AeroElectric-Archive.digest.vol-dx

January 16, 2005 - January 23, 2005



      
      Since I have never used an IFR certified WAAS receiver, possibly I  shouldn't 
      comment, but I have used three different handhelds that use WAAS  
      corrections.  Those units have all been very accurate and reliable.
      
      My gripe with WAAS is not with it's accuracy or it's reliability (I can't  
      begin to follow Keith's arguments as I don't have any idea how all that magic 
      
      works anyway), but with the way the FAA has chosen to implement that  accuracy.
      
      The LPV approaches, as designed under current development policy, primarily  
      provide a back up to existing ILS approaches. In order to execute an approach 
      
      much below three hundred AG, you must have some sort of ground based lighting 
       and/or markings to allow the transition to visual flight for the final 
      portion  of the approach.
      
      It is my feeling that we GA types would be better served if the FAA would  
      use the greater accuracy available with WAAS to tighten the error budget on the
      
      basic non precision approach so as to allow maximum use of existing TERPs  
      criteria to allow lower MDAs. 
      
      The current implementation policy for LPV approaches has, on  occasion, 
      actually caused circling minimums to be raised for the  accompanying NPAs.  That
      
      has resulted in NDB approaches to the same runway  having lower circling minima
      
      than does the vaunted WAAS approach.
      
      For some reason, which completely escapes me, the LNAV portion of an  RNAV 
      approach containing an LPV often has a lot higher MDA than did the GPS  which it
      
      replaces.
      
      Clearly, something is wrong with the implementation policy.
      
      Happy  Skies,
      
      Old Bob
      AKA
      Bob Siegfried
      Ancient Aviator
      Stearman  N3977A
      Brookeridge Airpark LL22
      Downers Grove, IL 60516
      630  985-8502
      
      
      
________________________________________________________________________________
From: Brian Lloyd <brianl(at)lloyd.com>
Subject: Re: TIS vs ADS-B
Date: Jan 16, 2005
On Jan 13, 2005, at 12:55 AM, Dj Merrill wrote: > Is ADS-B a "superset" of TIS? In other words, does > it display all of the TIS data, plus send your > aircraft position, or does it see only other ADS-B > traffic, and not include the radar info? > Which one is better overall for seeing more traffic? ADS-B is a system whereby each participating aircraft broadcasts its position and velocity to any listening station. TIS is a system whereby the ATC computers uplink their traffic information to an aircraft using a mode-S transponder. They are totally different systems. Now they can be combined as in ATC has ADS-B reception and repeats that information into TIS so you can see it in your cockpit but that does not equip you to see ADS-B traffic directly. Likewise, if you have ADS-B reception capability in your aircraft, it will only show you other ADS-B-equipped aircraft in your vicinity and not everything that ATC sees. Right now TIS appears to offer more information to the pilot since there are so few ADS-B-equipped aircraft in the lower 48. OTOH, TIS depends on you having transponder coverage and a link to ATC so it could go away along with all your traffic information. There are many places in the western US where you are not going to have RADAR/mode-S coverage. ADS-B is independent and distributed and so is pretty hard to break. In the long run I think that a distributed system like ADS-B is more desirable since it is going to be hard to break and is independent of anything on the ground. Brian Lloyd 6501 Red Hook Plaza brianl(at)lloyd.com Suite 201 +1.340.998.9447 St. Thomas, VI 00802 I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry ________________________________________________________________________________
From: Brian Lloyd <brianl(at)lloyd.com>
Subject: Re: RF Bypass
Date: Jan 16, 2005
On Jan 13, 2005, at 8:28 AM, richard dudley wrote: > > > Bob, > > I am using Van's + 0 - ammeter. I believe that Van's meters use an op > amp circuit. When I key my Comm2 transmitter, the meter pegs. This does > not happen with Comm1. I am suspecting that RF is the cause. I would > like to try a capacitor bypass from ammeter termnals to ground. What > capacitance would you suggest? .01 microfarad disc ceramic caps. Add ferrite beads to the wire also. Brian Lloyd 6501 Red Hook Plaza brianl(at)lloyd.com Suite 201 +1.340.998.9447 St. Thomas, VI 00802 I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry ________________________________________________________________________________
From: Brian Lloyd <brianl(at)lloyd.com>
Subject: Re: ultraviolet light dimmers
Date: Jan 16, 2005
On Jan 13, 2005, at 7:20 AM, lucky wrote: > > Speaking of Ultraviolet lights. Question for you all. In my WWII era > and post WWII era Dad's aircraft maintenance stuff there are a few > small boxes with rotary knobs on them that look like some kind of > ultraviolet light dimmers based upon the labelling. Was that that > type of light common in military transports and such back then? > Probably even into the 60s and early 70s? If so, why? Yes, it was common. Most instruments had their markings painted with florescent paint. They would glow green or yellow when illuminated with UV light. The advantage is that only the markings emitted light allowing you to see the instruments without a lot of glare that would compromise your night vision. The standard Nanachang CJ6A I fly is equipped with UV cockpit lighting. Most instrument overhaul shops can provide you with florescent instrument face markings if you request them. I did this when I replaced the Chinese altimeter, VSI, and manifold pressure gauges with US units. Brian Lloyd 6501 Red Hook Plaza brianl(at)lloyd.com Suite 201 +1.340.998.9447 St. Thomas, VI 00802 I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry ________________________________________________________________________________
From: Brian Lloyd <brianl(at)lloyd.com>
Subject: Re: ultraviolet light dimmers
Date: Jan 16, 2005
On Jan 13, 2005, at 10:11 AM, Kenneth Melvin wrote: > > > Most WW2-era aircraft were equipped with instruments with radium dials, > activated by ultraviolet cockpit lamps. Not quite. Many have Radium in their dials and they glow all the time without any UV light. The radioactive decay of the Radium provides the energy to make the markings glow. You could read the instruments even if you lost your electrical system. Later they did away with the Radium so you have to have the UV light source to make the instrument markings glow. It seems that the Chinese still use Radium or did until fairly recently. My 1984 CJ6A had Radium on the instrument and control markings. We had a bit of a scare when someone climbed into one with a geiger counter and discovered that nearly everything in the cockpit was radioactive! It turns out that the exposure is really small though. Brian Lloyd 6501 Red Hook Plaza brianl(at)lloyd.com Suite 201 +1.340.998.9447 St. Thomas, VI 00802 I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry ________________________________________________________________________________
Date: Jan 16, 2005
From: Kenneth Melvin <melvinke(at)direcway.com>
Subject: ultraviolet light dimmers
If you wish to quibble, I can tell you from personal experience that the flourescence in the AT6 and P51 Mustang dials (radium)was insignificant unless activated by the UV cockpit lamps. Kenneth Melvin. -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Brian Lloyd Subject: Re: AeroElectric-List: ultraviolet light dimmers On Jan 13, 2005, at 10:11 AM, Kenneth Melvin wrote: > > > Most WW2-era aircraft were equipped with instruments with radium > dials, activated by ultraviolet cockpit lamps. Not quite. Many have Radium in their dials and they glow all the time without any UV light. The radioactive decay of the Radium provides the energy to make the markings glow. You could read the instruments even if you lost your electrical system. Later they did away with the Radium so you have to have the UV light source to make the instrument markings glow. It seems that the Chinese still use Radium or did until fairly recently. My 1984 CJ6A had Radium on the instrument and control markings. We had a bit of a scare when someone climbed into one with a geiger counter and discovered that nearly everything in the cockpit was radioactive! It turns out that the exposure is really small though. Brian Lloyd 6501 Red Hook Plaza brianl(at)lloyd.com Suite 201 +1.340.998.9447 St. Thomas, VI 00802 I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry advertising on the Matronics Forums. ________________________________________________________________________________
From: "cgalley" <cgalley(at)qcbc.org>
Subject: Re: ultraviolet light dimmers
Date: Jan 16, 2005
I have a "radium" dial altimeter sitting on my desk. I have taken it into a pitch black room and I can't see anything. It is a ware surplus gage that came from the Bellanca factory in 1948. Still works fine and was built in 1943 by C.G. Conn a "real" instrument maker. says it is certified to 50,000 feet and has white alternated with green numerals on the dial. Cy Galley - Bellanca Champion Club Newsletter Editor-in-Chief & EAA TC www.bellanca-championclub.com Actively supporting Bellancas every day ----- Original Message ----- From: "Brian Lloyd" <brianl(at)lloyd.com> Subject: Re: AeroElectric-List: ultraviolet light dimmers > > > On Jan 13, 2005, at 10:11 AM, Kenneth Melvin wrote: > > > > > > > Most WW2-era aircraft were equipped with instruments with radium dials, > > activated by ultraviolet cockpit lamps. > > Not quite. Many have Radium in their dials and they glow all the time > without any UV light. The radioactive decay of the Radium provides the > energy to make the markings glow. You could read the instruments even > if you lost your electrical system. > > Later they did away with the Radium so you have to have the UV light > source to make the instrument markings glow. > > It seems that the Chinese still use Radium or did until fairly > recently. My 1984 CJ6A had Radium on the instrument and control > markings. We had a bit of a scare when someone climbed into one with a > geiger counter and discovered that nearly everything in the cockpit was > radioactive! It turns out that the exposure is really small though. > > Brian Lloyd 6501 Red Hook Plaza > brianl(at)lloyd.com Suite 201 > +1.340.998.9447 St. Thomas, VI 00802 > > I fly because it releases my mind from the tyranny of petty things . . . > Antoine de Saint-Exupry > > ________________________________________________________________________________
Date: Jan 16, 2005
From: Phil Birkelbach <phil(at)petrasoft.net>
Subject: Re: Cat 5
Category 5, 5e & 6 are all 4 unsheilded twisted pair wire for use in phone and computer networks. There are some very stringent requirements on the manufacturing of each that gives them suitable characteristics for the relatively high frequencies that they must carry. Most of these cables are solid conductor and most have PVC insulation. Tefzel insulation can handle heat much better than PVC. Both will give off noxious fumes when burning but Tefzel burns at a much higher temperature. You don't want to have any solid conductor wiring in your airplane. It won't hold up to vibration or stresses in installation nearly as well as stranded cable. The more strands the better. The normal aircraft grade tefzel wiring is very finely stranded which makes it much more flexible and robust. There is such thing as stranded Cat 5, it is generally used to make up patch cables. It is harder to find in rolls but you can buy some long patch cables and cut the ends off. If it were me I'd leave the Cat 5 in the network closet where it belongs and stick to aircraft grade wire. You can buy multi-conductor sheilded wire from a number of sources. I have some 5 conductor 26AWG, some 3 conductor 18AWG and some 4 conductor 24AWG tefzel wire in my plane. Then you have the comfort of knowing that you have wire in your airplane that was designed to be in an airplane. Godspeed, Phil Glen Matejcek wrote: > >Hi All- > >Can someone explain to me the significance of cat5 and or cat5e cable? >What makes it special? When would I want to use it vs a bundle of plain >old fashioned MS tefzel? > >Thanks guys- I haven't found any help locally! > > >Glen Matejcek >aerobubba(at)earthlink.net > > > > ________________________________________________________________________________
From: B Tomm <fvalarm(at)rapidnet.net>
Subject: avionics master
Date: Jan 16, 2005
How about a double pole master avionics switch with both poles wired in parellel to accomplish redundancy. Bevan RV7A fuse -----Original Message----- From: Rob Logan [SMTP:Rob(at)logan.com] Subject: AeroElectric-List: avionics master there are some items that don't have power buttons and one doesn't want on when you are trying to start the plane... in my case http://rob.com/lancair/Others/woody/2005.01/mahar-gp4-03-011205.pdf things like: FPD MFD AHRS T&B ALTRAK XPNDR ENCODER WSI WX500 so this is a perfect case for an avionics master.. as much as I hid in the lancair world http://lancair.net/lists/lml/ I must admit to having heard of this group and its distain for the avionics master switch... after some research it seemed to focus on "single point of failure" of the switch or relay feed. so what about two potter & brumfield switch/breakers to feed the avionics buss bar? this way either could feed the bar in the event the first failed. wouldn't that solve the single failure point and remove 9 switches for each thing on the avionics buss? Rob ________________________________________________________________________________
Date: Jan 16, 2005
From: Mickey Coggins <mick-matronics(at)rv8.ch>
Subject: Re: TIS vs ADS-B
> ... > > ADS-B is independent and distributed and so is pretty hard to break. > > In the long run I think that a distributed system like ADS-B is more > desirable since it is going to be hard to break and is independent of > anything on the ground. If the "pc revolution" and the internet have not convinced people that a distributed system is inherently more robust, then I guess nothing will. Do you know of any products for the experimental market that will at least broadcast ADS-B information? Not sure I can afford to receive it! -- Mickey Coggins http://www.rv8.ch/ #82007 Wiring ________________________________________________________________________________
From: "Glen Matejcek" <aerobubba(at)earthlink.net>
Subject: Cat 5
Date: Jan 16, 2005
Hi Guys- Thanks for your quick responses to my questions. I guess I should have read my post again before hitting send, as I worded it rather poorly. I have no particular desire to use the cat5 cables, but I have heard it mentioned and was wondering why. IE, what's the attraction. Does it have some special property, is it shielded, is it somehow superior for data transmission / EMI rejection, etc. Thanks again; you guys are a huge resource! Glen Matejcek aerobubba(at)earthlink.net ________________________________________________________________________________
From: Dww0708(at)aol.com
Date: Jan 16, 2005
Subject: Re: The dragon is slain . . . or at least hog-tied.
The ground fault system is pretty sensitive stuff. Kinda like if it ain t broke leave it be. Love hearing hangar floor stuff from a big shop. To make brake out boxes sounds devine but oh so expensive. Good Day ________________________________________________________________________________
From: BobsV35B(at)aol.com
Date: Jan 16, 2005
Subject: Re: ultraviolet light dimmers
In a message dated 1/16/2005 12:50:27 P.M. Central Standard Time, melvinke(at)direcway.com writes: If you wish to quibble, I can tell you from personal experience that the flourescence in the AT6 and P51 Mustang dials (radium)was insignificant unless activated by the UV cockpit lamps. Kenneth Melvin. Good Afternoon Kenneth, Just to quibble a bit, It All Depends on how old the instruments are, or were. When they were new, they glowed quite brightly even without the ultraviolet light. They also glowed better after some exposure to the UV lights, but that effect did wear down as the days went by. Getting in an airplane with brand new radium dials at night was an awesome experience. I didn't learn to fly until after WW II, but many of the airplanes that I worked on as an Aviation Electricians Mate were only a couple of years from brand new. Those panels glowed brightly at night long before we turned on the UV lights. Also, almost all of the airplanes in which I learned to fly in the late forties had surplus instruments which were no more than four or five years old. Those instruments glowed more than adequately with no UV lights installed in the airplane. Once Again, It All Depends! Happy Skies, Old Bob AKA Bob Siegfried Ancient Aviator Stearman N3977A Brookeridge Airpark LL22 Downers Grove, IL 60516 630 985-8502 ________________________________________________________________________________
From: BobsV35B(at)aol.com
Date: Jan 16, 2005
Subject: Re: WAAS or not
In a message dated 1/16/2005 2:24:30 P.M. Central Standard Time, cjensen(at)dts9000.com writes: I would think they'd want to focus on replacing/supplementing non-precision approaches with LNAV/VNAV instead of investing their time...and our money...in providing redundant service at aerodromes that already have ILS. I'm sure there's a logical explanation, but then, maybe they just didn't think about it when they were prioritizing--it happens. Chuck Good Afternoon Chuck, I have it on reasonably good authority that they started out trying to build those RNAVs at the small airports where they were most needed, but the air carrier and corporate types screamed bloody murder that they wanted to see that money spent where it would help them. The pressure they put on the FAA is a lot heavier than the pressure we produce. They are also the ones who have insisted that all approaches start out with the premise that they will eventually morph into a full automatic approach. To accommodate the fully automatic approach and landing, the approach path needs to be precisely lined up with the runway centerline. There needs to be a glide path available that will allow a constant angle all the way to touch down. When a high speed airplane is using that automatic approach, the flare maneuver is easier to accomplish if the rate of descent is low. In order to get a low rate of descent, you need to make a flat approach. Consequently, we end up with approaches that are perfectly aligned with the runway, that are capable of having a constant three degree glide path all the way to touch down and that have no fixes between the FAF and the DA or DH. All of that sounds good and I would like to have such an approach every place I have the need to land. Unfortunately, the obstacle environment of many small, lightly used, airports will not accommodate that style approach. Using a steeper approach path will work fine for any but automatic landings. One of the big reasons for using the MLS approach was that it was going to allow two approach segments, the first was much steeper with only the very last portion at something as flat as three degrees. There are quite few older approaches that have glide paths of four and a half degrees or more. Restricting us to the three degrees desired for high speed aircraft's automatic landing capability requires that fewer obstacles be in the approach area. If you tell the average competent Bonanza or Cessna Two Ten pilot to set up his own eyeballed glide path to the average small airport, you will find that most will set up about a four and a half degree angle of descent. In obstacle rich environments, it is common for the average pilot to use approach angles as steep a six degrees. IF the greater accuracy available with WAAS was to be used to allow us to get closer to obstacles, we could have lower minima If a steeper approach angle was used for Category A and B aircraft, we could get lower minima. IF the course was offset a few degrees so as to clear obstacles, we could get lower minima. IF suitable step downs were to be set up using that greater WAAS accuracy, we could get lower minima. Randy Kenagy of the AOPA staff is aware of these problems and is trying hard to get our voices heard, but the heavy iron boys speak with a stronger voice. Unless we are able to convince the appropriate local authorities to ask the FAA to build approaches the way we want them built, they will continue to build all approaches to accommodate the high speed, heavy aircraft that desire to make automatic landings. On top of that, the FAA is interpreting the rules in a way that is raising our circling minima at most runways that have a VLP. Very disgusting, and most folks don't even know it is happening! Happy Skies, Old Bob AKA Bob Siegfried Ancient Aviator Stearman N3977A Brookeridge Airpark LL22 Downers Grove, IL 60516 630 985-8502 ________________________________________________________________________________
Date: Jan 16, 2005
From: Graham Singleton <graham(at)gflight.f9.co.uk>
Subject: Re: AeroElectric-List Digest: 11 Msgs - 01/15/05
>The dragon is slain . . . or at least hog-tied. > > > >I think I mentioned that I've been extra ordinarily pre-occupied >with troubleshooting a tripping generator problem in a Beechjet for >the past few weeks. Thought I'd share some of the blood and gore >with our friends on the List. Fascinating Bob thanks for sharing that Graham, still in England -- Checked by AVG Anti-Virus. ________________________________________________________________________________
Date: Jan 16, 2005
From: D Fritz <dfritzj(at)yahoo.com>
Subject: Re: Dynon Efis
For those interested in how well the Dynon unit performs, I will give my impressions after using it for about 125 hours in a Thorp T-18. I bought the Dynon unit to act as backup to my Bluemountain Avionics EFIS-One in the Velocity I'm building. SInce I'm still a ways off from flying the Velocity and I had the Thorp at the time, I decided to mount it in the Thorp for some VFR evaluation of its performance. Overall, I was quite impressed with the performance of the unit AS A BACKUP, but would not launch into the weather with it as my only attitude reference (this was the original D-10 unit). The unit was quite stable in normal IFR flight (minor stepping in attitude as I maneuvered) and would serve just fine to perform an approach to full-stop landing. The unit was actually better than most of the backup attitude indicators I've had in the military aircraft I fly. I subjected the Dynon to a long test involving many 360 degree turns at progressively larger bank angles from 4 degrees to 60 degrees (try your patience sometime with a 4 degree banked 360 degree turn!) The Dynon performed flawlessly. However, on initial takeoff and chandelle type maneuvers (such as a closed pull-up, or first turn out of traffic), the unit had significant acceleration errors and frequently showed erroneous bank angles. This may have been addressed in future Dynon revisions; but was enough for me to swear off launching into the weather with only this unit as an attitude reference. This is all in keeping with what the Dynon folks are advertising as they say it is not intended for sole-source IFR flight. They have built a great little unit that I would trust for recovery and have used for several long night flights on moonless nights. Dan Fritz --------------------------------- ________________________________________________________________________________
From: Brian Lloyd <brianl(at)lloyd.com>
Subject: Re: Load Dump
Date: Jan 16, 2005
On Jan 12, 2005, at 4:58 PM, Paul Messinger wrote: > You may have a point as I do not think the regulator latched on unless > the > alternator is producing voltage above the battery alone voltage. It doesn't actually have to reach battery voltage level to turn on. The internally-regulated alternator 'bootstraps' itself into the on state. The regulator needs sufficient excitation to generate enough field current to activate the regulator. This can happen two ways: from the idiot light circuit or from the residual magnetism in the armature. When the idiot light is hooked up it provides just enough current to activate the regulator and provide a tiny field current (limited by the idiot lamp current). This is enough to begin to produce output in the unloaded stator. When the voltage rises high enough the diode trio conducts and provides power to the regulator independent of the idiot light circuit. As more current becomes available for the regulator to deliver to the field the greater power is available at the B+ terminal. Once it gets to that point the current is no longer needed from the idiot light circuit and the regulator stops drawing current from there. The idiot light then goes out. Most internally regulated alternators are self-exciting and don't need the idiot-light circuit. The residual magnetism in the armature is sufficient to produce enough power in the stator to power up the regulator. The regulator dumps that current into the field which produces more output. This process of positive feedback continues until the alternator is totally on. The only problem with this process is that you may have to spin the alternator up to a higher RPM to get this process to begin. Once on the regulator gets its power from the diode trio and you can't turn it off until you stop rotating the alternator. Some IR alternators have a separate input to provide initial excitation from the battery that is independent of the idiot-light circuit. In that case you just need to provide battery voltage on this terminal to provide the initial excitation to get the alternator to 'turn on' at low RPM. Once on this excitation is no longer needed and the alternator remains on until it stops rotating. If you want to operate an IR alternator as if it were an externally-regulated alternator, remove the diode trio and provide a lead from the battery bus to the input of the regulator. Now you can turn the alternator on and off just by controlling power on this lead. Brian Lloyd 6501 Red Hook Plaza brianl(at)lloyd.com Suite 201 +1.340.998.9447 St. Thomas, VI 00802 I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry ________________________________________________________________________________
From: BobsV35B(at)aol.com
Date: Jan 16, 2005
Subject: Re: WAAS or not
In a message dated 1/16/2005 4:24:16 P.M. Central Standard Time, deej(at)thayer.dartmouth.edu writes: They also don't have to add ground facilities to an airport to give it a decent WAAS GPS approach, so should be cheaper to add ILS-like approaches to many airports for the cost of a single ILS installation at a single airport. Good Evening DJ, That sounds good, but it doesn't work out well in practice. Getting down to two hundred feet above the ground and then trying to find that average small airport runway just doesn't work. Part and parcel of an ILS, or an ILS loo kalike guided by GPS, is the approach light system. Without the approach lights, there is no way you can have an approach that only requires one half mile visibility. Without such lighting, the visibility requirement is generally a minimum of one mile. So far so good. Let us suppose that the powers that be decide to draw an approach to Podunk Runway 30 that has nothing more than medium intensity runway lighting. Let's even say there are no obstacles in either the approach path or the departure path. It is not at all unlikely that a DH of 300 feet would be established. At three hundred feet on a three degrees glide path, the airplane would be almost one mile from the runway. If the ceiling is at three hundred feet, that means the pilot has one or two seconds to locate the runway and transition to a visual landing for that last mile. How good a chance do you think the average transient pilot would have of seeing that runway? I think that pilot would have much better chance of making a successful approach and landing if there was an MDA at four hundred feet and the visibility requirement was one mile. The pilot could descend to four hundred feet. He/she could then maintain level flight at that altitude until the runway was absolutely in sight. If the aircraft was then too close to the airport to land straight in, it would be duck soup to circle and land from a nice one eighty side approach. Much easier than trying to dive down and land on a suddenly appearing runway. Incidentally, if that airport truly does have absolutely no obstacles nearby, the lowest possible circling MDA could be three hundred feet. Circling at three hundred feet can be done safely, but it need to be trained for and such training is rarely, if ever, given. While such a low circling minima is possible, I know of none that are. Incidentally, the FAA has recently added the circling approach to the list of things that are to be accomplished on an Instrument Competency Check. I think that is great idea. All of the emphasis on shooting ILS and ILS lookalike approaches have meant that very few folks have any idea of the procedures required to safely and efficiently execute circling approaches in minimum weather conditions. Happy Skies, Old Bob AKA Bob Siegfried Ancient Aviator Stearman N3977A Brookeridge Airpark LL22 Downers Grove, IL 60516 630 985-8502 ________________________________________________________________________________
From: KITFOXZ(at)aol.com
Date: Jan 16, 2005
Subject: Re: avionics master
In a message dated 1/16/2005 3:12:19 P.M. Eastern Standard Time, fvalarm(at)rapidnet.net writes: How about a double pole master avionics switch with both poles wired in parellel to accomplish redundancy. Bevan RV7A fuse That still leaves you with a single point failure item: The mechanics of the single switch. John P. Marzluf Columbus, Ohio Kitfox Outback (out back in the garage) ________________________________________________________________________________
From: Brian Lloyd <brianl(at)lloyd.com>
Subject: Re: ultraviolet light dimmers
Date: Jan 16, 2005
On Jan 16, 2005, at 1:10 PM, Kenneth Melvin wrote: > > > If you wish to quibble, I can tell you from personal experience that > the > flourescence in the AT6 and P51 Mustang dials (radium)was insignificant > unless activated by the UV cockpit lamps. I wasn't quibbling. I was pointing out that some instruments had Radium/florescent paint and some had florescent-only paint (no Radium). The US stopped using Radium paint in the early '50s as I recall. Many WW-II vintage instruments are classified as radioactive waste and cannot be worked on by instrument shops because of the Radium in their markings. I know that the Radium paint doesn't glow brightly without the UV lights but it does glow and is readily readable in the dark when your eyes become dark-adapted even without the excitation of the UV light. I had an airplane with Radium-painted instruments and cockpit control markings and UV lighting. Brian Lloyd 6501 Red Hook Plaza brianl(at)lloyd.com Suite 201 +1.340.998.9447 St. Thomas, VI 00802 I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry ________________________________________________________________________________
From: Brian Lloyd <brianl(at)lloyd.com>
Subject: Re: ultraviolet light dimmers
Date: Jan 16, 2005
On Jan 16, 2005, at 2:00 PM, cgalley wrote: > > I have a "radium" dial altimeter sitting on my desk. I have taken it > into a > pitch black room and I can't see anything. It is a ware surplus gage > that > came from the Bellanca factory in 1948. Still works fine and was built > in > 1943 by C.G. Conn a "real" instrument maker. says it is certified to > 50,000 > feet and has white alternated with green numerals on the dial. If there is no discernible glow when in a dark room after your eyes are dark-adapted then the paint is probably Radium-free. A geiger counter or other detector of alpha particles will tell you but you may have to remove the glass face as glass will stop alpha particles. You can get florescent instrument markings without Radium. I suspect some WW-II instruments were so painted. Brian Lloyd 6501 Red Hook Plaza brianl(at)lloyd.com Suite 201 +1.340.998.9447 St. Thomas, VI 00802 I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry ________________________________________________________________________________
From: Brian Lloyd <brianl(at)lloyd.com>
Subject: Re: ultraviolet light dimmers
Date: Jan 16, 2005
On Jan 16, 2005, at 4:08 PM, BobsV35B(at)aol.com wrote: > Just to quibble a bit, It All Depends on how old the instruments are, > or > were. Radium-226, the material used in instrument markings, has a half-life of 1600 years. If the instrument faces were painted with florescent paint containing Radium, they would still be glowing about 97% as brightly now as when they were made 60 years ago. Nowadays Tritium (H3) is used for glow-in-the-dark marking on gun sights and wristwatches. It has a half-life of 12.3 years so it does indeed get noticeably dimmer with time. Brian Lloyd 6501 Red Hook Plaza brianl(at)lloyd.com Suite 201 +1.340.998.9447 St. Thomas, VI 00802 I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry ________________________________________________________________________________
Date: Jan 16, 2005
From: Steve Thomas <lists(at)stevet.net>
Subject: Turn and Push Knob
Hello aeroelectric-list, I'm looking for a high-quality turn and push switch. The turn function will scroll through a series of menu items and the push will select that function. Any suggestions from anyone who has found a good component? -- Best regards, Steve mailto:lists(at)stevet.net.nospam ________________________________________________________________________________
From: "Paul Messinger" <paulm(at)olypen.com>
Subject: Re: Load Dump
Date: Jan 16, 2005
Interesting, but you are not looking at the Jap alternators I have experience with, which are wired somewhat differently. They REQUIRE the external power on to start and then can NOT be turned off. Also they have a direct connection from the "B" lead to the regulator. The number of diodes and configuration vary but the ND, HI, and MI brands I have looked at, but all have direct internal connection to the "B" lead and no diodes in line etc.to the reg power. Thus its not the diodes you need to cut its the direct "B" lead connection and then also bring out the REG power lead in addition to needing the ON lead and in some cases the idiot light is an essential part of the circuit. Your point is important as EVERY brand and various models within a brand are somewhat different. USA brands are quite different (at least in those I have looked at) from the Jap brands. ALL the more reason to forget internally regulated alternators and use an external regulator. Paul ----- Original Message ----- From: "Brian Lloyd" <brianl(at)lloyd.com> Subject: Re: AeroElectric-List: Load Dump > > On Jan 12, 2005, at 4:58 PM, Paul Messinger wrote: > > You may have a point as I do not think the regulator latched on unless > > the > > alternator is producing voltage above the battery alone voltage. > > It doesn't actually have to reach battery voltage level to turn on. > > The internally-regulated alternator 'bootstraps' itself into the on > state. The regulator needs sufficient excitation to generate enough > field current to activate the regulator. This can happen two ways: from > the idiot light circuit or from the residual magnetism in the armature. > > When the idiot light is hooked up it provides just enough current to > activate the regulator and provide a tiny field current (limited by the > idiot lamp current). This is enough to begin to produce output in the > unloaded stator. When the voltage rises high enough the diode trio > conducts and provides power to the regulator independent of the idiot > light circuit. As more current becomes available for the regulator to > deliver to the field the greater power is available at the B+ terminal. > Once it gets to that point the current is no longer needed from the > idiot light circuit and the regulator stops drawing current from there. > The idiot light then goes out. > > Most internally regulated alternators are self-exciting and don't need > the idiot-light circuit. The residual magnetism in the armature is > sufficient to produce enough power in the stator to power up the > regulator. The regulator dumps that current into the field which > produces more output. This process of positive feedback continues until > the alternator is totally on. The only problem with this process is > that you may have to spin the alternator up to a higher RPM to get this > process to begin. Once on the regulator gets its power from the diode > trio and you can't turn it off until you stop rotating the alternator. > > Some IR alternators have a separate input to provide initial excitation > from the battery that is independent of the idiot-light circuit. In > that case you just need to provide battery voltage on this terminal to > provide the initial excitation to get the alternator to 'turn on' at > low RPM. Once on this excitation is no longer needed and the alternator > remains on until it stops rotating. > > If you want to operate an IR alternator as if it were an > externally-regulated alternator, remove the diode trio and provide a > lead from the battery bus to the input of the regulator. Now you can > turn the alternator on and off just by controlling power on this lead. > > Brian Lloyd 6501 Red Hook Plaza > brianl(at)lloyd.com Suite 201 > +1.340.998.9447 St. Thomas, VI 00802 > > I fly because it releases my mind from the tyranny of petty things . . . > Antoine de Saint-Exupry > > ________________________________________________________________________________
From: Brian Lloyd <brianl(at)lloyd.com>
Subject: Re: WAAS or not
Date: Jan 16, 2005
On Jan 16, 2005, at 4:44 PM, Dj Merrill wrote: > One reason I can think of is that ILS requires > ground facilities, and GPS does not. In theory, maintaining > the GPS system is cheaper in the long run than maintaining > all of the ground installations of ILS across the country. I am not sure that is true. As I recall, it was costing about $40M each for the LORAN and VOR/DME systems per year. GPS maintenance was over $2B per year. Big difference. I can't imagine that the ILS systems cost that much more. > They also don't have to add ground facilities to an airport > to give it a decent WAAS GPS approach, so should be cheaper to > add ILS-like approaches to many airports for the cost of > a single ILS installation at a single airport. The key point is, once you have paid for the GPS system, you may as well use it. OTOH, it ain't cheap. Brian Lloyd 6501 Red Hook Plaza brianl(at)lloyd.com Suite 201 +1.340.998.9447 St. Thomas, VI 00802 I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry ________________________________________________________________________________
From: "Sam Chambers" <schamber@glasgow-ky.com>
Subject: Re: avionics master
Date: Jan 16, 2005
Doesn't provide mechanical redundancy. See Aeroelectric Connection articles to determine if you really want/need an avionics master. Sam Chambers Long-EZ N775AM EAA Tech & Flt Advisor ----- Original Message ----- From: "B Tomm" <fvalarm(at)rapidnet.net> Subject: RE: AeroElectric-List: avionics master > > How about a double pole master avionics switch with both poles wired in parellel to accomplish redundancy. > > Bevan > RV7A fuse > > -----Original Message----- > From: Rob Logan [SMTP:Rob(at)logan.com] > Sent: Friday, January 14, 2005 4:02 PM > To: aeroelectric-list(at)matronics.com > Subject: AeroElectric-List: avionics master > > > there are some items that don't have power buttons > and one doesn't want on when you are trying to start > the plane... in my case > http://rob.com/lancair/Others/woody/2005.01/mahar-gp4-03-011205.pdf > things like: > > FPD > MFD > AHRS > T&B > ALTRAK > XPNDR > ENCODER > WSI > WX500 > > so this is a perfect case for an avionics master.. as much > as I hid in the lancair world http://lancair.net/lists/lml/ > I must admit to having heard of this group and its distain for > the avionics master switch... after some research it seemed > to focus on "single point of failure" of the switch or relay > feed. so what about two potter & brumfield switch/breakers > to feed the avionics buss bar? this way either could feed > the bar in the event the first failed. wouldn't that solve > the single failure point and remove 9 switches for each > thing on the avionics buss? > > Rob > > ________________________________________________________________________________
Date: Jan 16, 2005
From: Dj Merrill <deej(at)thayer.dartmouth.edu>
Subject: Re: WAAS or not
BobsV35B(at)aol.com wrote: > That sounds good, but it doesn't work out well in practice. Getting down to > two hundred feet above the ground and then trying to find that average small > airport runway just doesn't work. Part and parcel of an ILS, or an ILS loo > kalike guided by GPS, is the approach light system. Hi Bob, I'm not instrument rated yet, so take this for what it might not be worth... :-) There are bunches of smaller airports that don't have any approach, or at best an NDB approach. An ILS-like approach with WAAS, even if it has higher minimums, would seem to be an improvement for a lot of these airports. No additional ground facilities would have to be added. If there is some extra $$$, adding the extra lights to lower the minimums would be great, and still a lot cheaper since you don't have to add the ground radio ILS equipment. IMHO the positives of WAAS far outweigh any negatives that I can think of. GPS WAAS, TIS, ADS-B, in-flight weather, in-flight terrain, etc., are revolutionizing the way we think of IFR, IMHO. -Dj -- Dj Merrill deej(at)thayer.dartmouth.edu "TSA: Totally Screwing Aviation" ________________________________________________________________________________
From: Benford2(at)aol.com
Date: Jan 16, 2005
Subject: Re: WAAS or not
In a message dated 1/16/2005 1:24:30 PM Mountain Standard Time, cjensen(at)dts9000.com writes: > I would think they'd want to focus on > replacing/supplementing non-precision approaches with LNAV/VNAV instead of > investing their time...and our money...in providing redundant service at > aerodromes that already have ILS. I'm sure there's a logical explanation This comes from the same government that has us 7+ TRILLION in debt. The FAA has failed in the computer modernization, and just this week the news announced the 175 million FBI system to cross check info was a complete failure. My thoughts are to investigate all option, test all the systems and make a "logical" decision to fly behind a navagation source you feel comfortable with. IMHO the GPS system is pretty hard to beat unless it gets disabled by a offshore threat or some other malfunction. When that happens all hell will breakout... Ben Haas N801BH ________________________________________________________________________________
From: "cgalley" <cgalley(at)qcbc.org>
Subject: Re: WAAS or not
Date: Jan 16, 2005
Seems the numbers I heard was that ONE satellite was the cost of ONE ILS approach. There are only about 25 satellites but the are many more ILS approaches. there are at least 2 at our airport alone. Cy Galley EAA Safety Programs Editor Always looking for ideas and articles for EAA Sport Pilot ----- Original Message ----- From: "Brian Lloyd" <brianl(at)lloyd.com> Subject: Re: AeroElectric-List: WAAS or not > > On Jan 16, 2005, at 4:44 PM, Dj Merrill wrote: > > > One reason I can think of is that ILS requires > > ground facilities, and GPS does not. In theory, maintaining > > the GPS system is cheaper in the long run than maintaining > > all of the ground installations of ILS across the country. > > I am not sure that is true. As I recall, it was costing about $40M each > for the LORAN and VOR/DME systems per year. GPS maintenance was over > $2B per year. Big difference. I can't imagine that the ILS systems cost > that much more. > > > They also don't have to add ground facilities to an airport > > to give it a decent WAAS GPS approach, so should be cheaper to > > add ILS-like approaches to many airports for the cost of > > a single ILS installation at a single airport. > > The key point is, once you have paid for the GPS system, you may as > well use it. OTOH, it ain't cheap. > > Brian Lloyd 6501 Red Hook Plaza > brianl(at)lloyd.com Suite 201 > +1.340.998.9447 St. Thomas, VI 00802 > > I fly because it releases my mind from the tyranny of petty things . . . > Antoine de Saint-Exupry > > ________________________________________________________________________________
Date: Jan 16, 2005
From: Kevin Horton <khorton01(at)rogers.com>
Subject: Re: Dynon Efis
> >For those interested in how well the Dynon unit performs, I will >give my impressions after using it for about 125 hours in a Thorp >T-18. I bought the Dynon unit to act as backup to my Bluemountain >Avionics EFIS-One in the Velocity I'm building. SInce I'm still a >ways off from flying the Velocity and I had the Thorp at the time, I >decided to mount it in the Thorp for some VFR evaluation of its >performance. Overall, I was quite impressed with the performance of >the unit AS A BACKUP, but would not launch into the weather with it >as my only attitude reference (this was the original D-10 unit). >The unit was quite stable in normal IFR flight (minor stepping in >attitude as I maneuvered) and would serve just fine to perform an >approach to full-stop landing. The unit was actually better than >most of the backup attitude indicators I've had in the military >aircraft I fly. I subjected the Dynon to a long test involving many >360 degree turns at progressively larger bank angles from 4 > degrees > to 60 degrees (try your patience sometime with a 4 degree banked >360 degree turn!) The Dynon performed flawlessly. However, on >initial takeoff and chandelle type maneuvers (such as a closed >pull-up, or first turn out of traffic), the unit had significant >acceleration errors and frequently showed erroneous bank angles. >This may have been addressed in future Dynon revisions; but was >enough for me to swear off launching into the weather with only this >unit as an attitude reference. This is all in keeping with what the >Dynon folks are advertising as they say it is not intended for >sole-source IFR flight. They have built a great little unit that I >would trust for recovery and have used for several long night >flights on moonless nights. > >Dan Fritz > > I'd like to confirm one thing - did you have the Dynon EFIS connected to the pitot and static systems? The reason I ask is that I understand that they use the airspeed input to partially correct for acceleration errors. The unit might behave strangely if it saw accelerations but no airspeed. Thanks for the Dynon report. -- Kevin Horton RV-8 (finishing kit) Ottawa, Canada http://go.phpwebhosting.com/~khorton/rv8/ ________________________________________________________________________________
Date: Jan 16, 2005
From: "Richard E. Tasker" <retasker(at)optonline.net>
Subject: Re: avionics master
And the mechanics are the more likely to fail if the contacts are used within their ratings. Dick Tasker KITFOXZ(at)aol.com wrote: > > >In a message dated 1/16/2005 3:12:19 P.M. Eastern Standard Time, >fvalarm(at)rapidnet.net writes: > >How about a double pole master avionics switch with both poles wired in >parellel to accomplish redundancy. > >Bevan >RV7A fuse > > >That still leaves you with a single point failure item: The mechanics of the >single switch. > >John P. Marzluf >Columbus, Ohio >Kitfox Outback (out back in the garage) > > > > ________________________________________________________________________________
Subject: Re: WAAS or not
Date: Jan 16, 2005
From: "John Schroeder" <jschroeder(at)perigee.net>
Chuck - Where did you install your antenna? What kind of airplane is the CNX-80 installed in. We are about to install our antenna and your experience might be very helpful and timely. Thanks, John Schroeder Lancair ES > Only another single data point but I've been flying the CNX80 (ne Garmin > 480) with WAAS turned on and have yet to see a loss of signal, loss of > position or failure of RAIM to be sat for the approach. I can't imagine > that I'm favored with particularly good GPS service in Tennessee. Why > would > GPS be different then everything else in TN? ________________________________________________________________________________
From: BobsV35B(at)aol.com
Date: Jan 16, 2005
Subject: Re: avionics master
In a message dated 1/16/2005 6:48:14 P.M. Central Standard Time, gmcnutt(at)shaw.ca writes: It seems to me that a bigger problem would be a master switch that is slowly failing with burned contacts. Am I wrong in assuming a slowly failing switch will be running hot and will be detected when I run my hand along the back of my switch bank as I occasionally do after a flight? Do not archive. Good Evening George in Langley BC, While the folks here generally don't like Master Avionics Switches, one popular method is the one used by Beechcraft on their production airplanes. They use a master relay or contactor which is in the normally closed position. When the master switch is turned "off", it is actually closed and sends power to the contactor coil so as to open the circuit. The theory being that if the power to the switch fails, the contactor will fall to the closed position and power the Avionics Buss. My spam can came with such an arrangement and it has served me well for lo these many years. Happy Skies, Old Bob AKA Bob Siegfried Ancient Aviator Stearman N3977A Brookeridge Airpark LL22 Downers Grove, IL 60516 630 985-8502 ________________________________________________________________________________
From: BobsV35B(at)aol.com
Date: Jan 17, 2005
Subject: Re: WAAS or not
In a message dated 1/16/2005 9:11:52 P.M. Central Standard Time, deej(at)thayer.dartmouth.edu writes: An ILS-like approach with WAAS, even if it has higher minimums, would seem to be an improvement for a lot of these airports. Good Evening DJ, There is no question that the ILS lookalike is easier to fly. The problem is that when the weather is bad, you are going to have to miss an approach that could be safely conducted using a standard level flight segment non precision approach. It is my opinion that the vertically navigated approaches should be built, but they should also include a non precision approach if that approach will allow lower minima. We shoot approaches in bad weather to make a safe landing at an airport, not just to practice our flying skills. At airports located in high obstacle fields, the lowest minima will almost always be via a non precision level flight segment approach. In the situation where the required MDA is at six hundred feet or more, the circling approach is almost always going to allow a successful approach in conditions where a straight in approach would result in a miss. I don't think there is anyone, me included, who does not prefer the ILS look alike approach, but if the intent is to land rather than to just execute the approach, the NPA should be available as well as the vertically guided one. In addition to just providing that NPA, it should be built using the WAAS accuracy instead of the VOR accuracy currently being used. If that is done, the WAAS will be doing what it is capable of doing. Providing us with a safe method of operating in challenging weather conditions. Some folks never want to shoot approaches at all. They have an instrument rating to allow easier and safer enroute flight. Nothing wrong with that. Other folks regularly add a couple of hundred feet to every published minima. That is also a fine thing to do. No one should fly in any weather that does not feel comfortable to them. Those who do not feel qualified to execute the approaches that will allow the lowest minima should establish the minima they are comfortable with and divert to an alternate if minimum conditions exist. All of those options are appropriate, but for those of us who do have the training and equipment to execute approaches to the lowest minimums authorized, we should have such approaches available. The FAA regulations allow such approaches to be built, but they won't be built if we do not ask for them. Unfortunately, very few instructors are teaching the fine points of non precision approaches, let alone the quirks and twists required for safe and efficient circling approaches. The regulations allow them and they can be safely conducted if the pilot is properly trained and maintains adequate proficiency. Isn't that true of every thing we do with airplanes? Happy Skies, Old Bob AKA Bob Siegfried Ancient Aviator Stearman N3977A Brookeridge Airpark LL22 Downers Grove, IL 60516 630 985-8502 ________________________________________________________________________________
From: BobsV35B(at)aol.com
Date: Jan 17, 2005
Subject: WAAS or Not
In a message dated 1/16/2005 9:11:52 P.M. Central Standard Time, deej(at)thayer.dartmouth.edu writes: An ILS-like approach with WAAS, even if it has higher minimums, would seem to be an improvement for a lot of these airports. Good Evening DJ, There is no question that the ILS lookalike is easier to fly. The problem is that when the weather is bad, you are going to have to miss an approach that could be safely conducted using a standard level flight segment non precision approach. It is my opinion that the vertically navigated approaches should be built, but they should also include a non precision approach if that approach will allow lower minima. We shoot approaches in bad weather to make a safe landing at an airport, not just to practice our flying skills. At airports located in high obstacle fields, the lowest minima will almost always be via a non precision level flight segment approach. In the situation where the required MDA is at six hundred feet or more, the circling approach is almost always going to allow a successful approach in conditions where a straight in approach would result in a miss. I don't think there is anyone, me included, who does not prefer the ILS look alike approach, but if the intent is to land rather than to just execute the approach, the NPA should be available as well as the vertically guided one. In addition to just providing that NPA, it should be built using the WAAS accuracy instead of the VOR accuracy currently being used. If that is done, the WAAS will be doing what it is capable of doing. Providing us with a safe method of operating in challenging weather conditions. Some folks never want to shoot approaches at all. They have an instrument rating to allow easier and safer enroute flight. Nothing wrong with that. Other folks regularly add a couple of hundred feet to every published minima. That is also a fine thing to do. No one should fly in any weather that does not feel comfortable to them. Those who do not feel qualified to execute the approaches that will allow the lowest minima should establish the minima they are comfortable with and divert to an alternate if minimum conditions exist. All of those options are appropriate, but for those of us who do have the training and equipment to execute approaches to the lowest minimums authorized, we should have such approaches available. The FAA regulations allow such approaches to be built, but they won't be built if we do not ask for them. Unfortunately, very few instructors are teaching the fine points of non precision approaches, let alone the quirks and twists required for safe and efficient circling approaches. The regulations allow them and they can be safely conducted if the pilot is properly trained and maintains adequate proficiency. Isn't that true of every thing we do with airplanes? Happy Skies, Old Bob AKA Bob Siegfried Ancient Aviator Stearman N3977A Brookeridge Airpark LL22 Downers Grove, IL 60516 630 985-8502 ________________________________________________________________________________
From: "Werner Schneider" <glastar(at)gmx.net>
Subject: Re: Dynon Efis
Date: Jan 17, 2005
Fritz, what software version are you using, as they have a better sampling rate on the newest one I would love to hear what a new version will perform like in a chandelle type maneuvers. You would need at least version 1.10 (actual is 1.12). Keep us updated Werner BTW did you also compare the BMA EFIS in this conditions? ----- Original Message ----- From: "D Fritz" <dfritzj(at)yahoo.com> Subject: Re: AeroElectric-List: Dynon Efis > > For those interested in how well the Dynon unit performs, I will give my impressions after using it for about 125 hours in a Thorp T-18. I bought the Dynon unit to act as backup to my Bluemountain Avionics EFIS-One in the Velocity I'm building. SInce I'm still a ways off from flying the Velocity and I had the Thorp at the time, I decided to mount it in the Thorp for some VFR evaluation of its performance. Overall, I was quite impressed with the performance of the unit AS A BACKUP, but would not launch into the weather with it as my only attitude reference (this was the original D-10 unit). The unit was quite stable in normal IFR flight (minor stepping in attitude as I maneuvered) and would serve just fine to perform an approach to full-stop landing. The unit was actually better than most of the backup attitude indicators I've had in the military aircraft I fly. I subjected the Dynon to a long test involving many 360 degree turns at progressively larger bank angles from 4 > degrees > to 60 degrees (try your patience sometime with a 4 degree banked 360 degree turn!) The Dynon performed flawlessly. However, on initial takeoff and chandelle type maneuvers (such as a closed pull-up, or first turn out of traffic), the unit had significant acceleration errors and frequently showed erroneous bank angles. This may have been addressed in future Dynon revisions; but was enough for me to swear off launching into the weather with only this unit as an attitude reference. This is all in keeping with what the Dynon folks are advertising as they say it is not intended for sole-source IFR flight. They have built a great little unit that I would trust for recovery and have used for several long night flights on moonless nights. > > Dan Fritz > > > --------------------------------- > > ________________________________________________________________________________
From: Brian Lloyd <brianl(at)lloyd.com>
Subject: Re: WAAS or not
Date: Jan 17, 2005
On Jan 16, 2005, at 11:02 PM, cgalley wrote: > Seems the numbers I heard was that ONE satellite was the cost of ONE > ILS > approach. There are only about 25 satellites but the are many more ILS > approaches. there are at least 2 at our airport alone. I like GPS. It is wonderful. I have an IFR-certified GPS in each of my airplanes. It is not cheap though. The numbers from about five years back are as follows: Annual cost to operate LORAN -- $29M Annual cost to operate GPS -- $400M Cost to deploy GPS -- $10.5B Cost for WAAS was supposed to be -- $1B (it went way over budget) The costs have gone up substantially, especially for WAAS. The Europeans have it right with their system that will do WAAS by transmitting the corrections via LORAN. The nice thing is that their WAAS datalink acts as a backup area navigation. If their satellites go down for whatever reason, you can still find your way to your destination. The way that the FAA is going we will have no backup navigation system. I do not advocate getting rid of GPS -- far from it. We need GPS. It is just that it is monstrously more expensive than either VOR or LORAN for navigation and it is easily jammed. The WAAS system is very poorly designed. What it boils down to is that I *really* want the FAA to keep VOR and/or LORAN navigation around. I don't want to find out that some bad guy has laid hands on one of the $4000 Russian GPS jammers just as I am making a precision VLP approach to minimums on some dark and stormy night after the FAA has 'retired' the VOR and LORAN systems. Someone at the FAA needs to get a clue about systems design. Oh yeah, I forget: "Hi, I'm from the FAA and I am here to help." "Here at the FAA we're not happy until you're not happy!" Brian Lloyd 6501 Red Hook Plaza brianl(at)lloyd.com Suite 201 +1.340.998.9447 St. Thomas, VI 00802 I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry ________________________________________________________________________________
Date: Jan 17, 2005
Subject: Re: WAAS or not
From: "John Schroeder" <jschroeder(at)perigee.net>
Hey guys - I doubt if comparing the cost of installing and maintaining the ILS systems vs. the costs to the FAA of implementing WAAS can be done easily. Nor can we blame the loss of signal when not looking at the southern skies on the FAA, as Rob suggests. As Brian notes, the FAA bears little, if any of the cost of the basic GPS system. The architecture is designed for truly world-wide operations by the DOD - not for 95% reliability of navigation by us good GA users. I also believe that the Coast Guard is OPR for the Loran system. Like so many other items benefitting the citizenry, the DOD picks up the huge tab for this wonderful system - not only for U.S. citizens but for the entire world!! Terrorists, drug runners, thugs included. This phenom (almost complete loss of control of a strategic system by its owner) is probably one of the great case studies of public policy, along with the fairly large chunks of money Congress adds to the DOD budget for breast and prostate cancer research every year. And there are many more tucked away in the thousands of line items in that budget. Don't get me wrong. GPS and its progeny, such as moving maps, is perhaps the single most important technological contribution to general aviation in the last 50 years. Now all we need to do is lobby the Hill; get Congress to add a chunk of money to the DOD bill every year for about a decade and have it earmarked for building a 95% reliable WAAS system for us. :-)) Just some off-the-wall thoughts. Cheers, John Schroeder >> I am not sure that is true. As I recall, it was costing about $40M each >> for the LORAN and VOR/DME systems per year. GPS maintenance was over >> $2B per year. Big difference. I can't imagine that the ILS systems cost >> that much more. > > Hi Brian, > I don't have any reports or anything to refer to, but I remember > reading some time ago that this > was one of the selling points for them > moving towards it. The GPS system is maintained to serve > > multiple uses, not just aviation, so the overall cost to aviation of GPS > is cheaper than the > ILS/VOR/NDB cost times the number of installations at/near airports. > ________________________________________________________________________________
Date: Jan 17, 2005
From: D Fritz <dfritzj(at)yahoo.com>
Subject: Re: Dynon Efis
Yes, the Dynon was completely installed in the system, plumbed to pitot and static and running on ship's power. Incidentally, I was using the internal magnetometer vice the remote option; also, I did not experience any of the noise interference on my radio that other Dynon users had reported. Dan Fritz "I'd like to confirm one thing - did you have the Dynon EFIS connected to the pitot and static systems? The reason I ask is that I understand that they use the airspeed input to partially correct for acceleration errors. The unit might behave strangely if it saw accelerations but no airspeed. Thanks for the Dynon report. -- Kevin Horton RV-8 (finishing kit) Ottawa, Canada http://go.phpwebhosting.com/~khorton/rv8/" --------------------------------- ________________________________________________________________________________
Date: Jan 17, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: avionics master
> >if switch failure is still an issue for airplanes operated at the >relatively low frequency of most recreational GA aircraft then why not >just go ahead and replace the switch every 5 years or something and not >worry about it. > >Anyone on the list actually had a toggle switch fail on a GA aircraft? It's NOT just the switch . . . how about wires and terminals that route from the main bus to the "avionics bus"? If you review chapter 17 from the 'Connection at: http://aeroelectric.com/articles/Rev9/ch17-9.pdf . . . then consider what features you'd like for your airplane to carry when things are not going well with the electrical system. One feature of the e-bus concept is DUAL power pathways to the bus . . . one from what SHOULD be the most reliable power source in the airplane; the BATTERY. The second feature is automatic and very simple load-shedding to put the airplane into an ENDURANCE mode of en route operations that will ASSURE comforable arrival at the airport of intended destination . . . not at some remote field less than 30 minutes from your present location. The third feature is driven by the notion that an avionics master switch was conceived based on poor understanding of the relationship between solid state devices -AND- the power generation and distribution system. There is no foundation in physics or good design that calls for installation of what has become popularized as an avionics master switch. Rather than getting bogged down in debating the reliability of any particular switch or associated hardware, why not ASSUME that the switch or wires WILL fail at some point in time . . . What is your "Plan B" for dealing with that situation? I'll suggest that the dual supply path e-bus concept is at least one rational approach . . . if you have others to suggest, let's consider them. But most important: make your design decisions based on understanding of supporting simple ideas and be very wary of ol' hangar tales and well worn traditions that are not supported with physics. Bob . . . ________________________________________________________________________________
Date: Jan 17, 2005
From: D Fritz <dfritzj(at)yahoo.com>
Subject: Re: Dynon Efis
Werner, I had one of the early units and updated the software once or twice, probably not up to the 1.10 version. I can't say for sure as I've sold the aircraft and last flew it in May '04. I did not compare these results with the Bluemountain unit since it was not installed in the Thorp. I'll have to wait until the Velocity is flying to do that test; however, I'm told Bluemountain went to great lengths to successfully avoid these errors through the use of GPS aiding in their filters. Dan Fritz --------------------------------- ________________________________________________________________________________
From: "Wayne Sweet" <w_sweet(at)comcast.net>
Subject: Re: WAAS or not
Date: Jan 17, 2005
Brian, The LORAN I flew with for a few years was, well, adequate, but lost track several times in the most inopportune times. I was delighted to remove it and install the first GPS. Since then, zero lost tracks, zero problems with the Apollo 2001, UPS GX50 and now the GNS430. To use LORAN in conjunction with a GPS system is a bit bizarre. VOR's will go the way of NDB's. Never heard of a device that jams GPS signals. How does such equipment interfere with signals from 25 satellites over a wide geographical area? Wayne ----- Original Message ----- From: "Brian Lloyd" <brianl(at)lloyd.com> Subject: Re: AeroElectric-List: WAAS or not > > On Jan 16, 2005, at 11:02 PM, cgalley wrote: > >> Seems the numbers I heard was that ONE satellite was the cost of ONE >> ILS >> approach. There are only about 25 satellites but the are many more ILS >> approaches. there are at least 2 at our airport alone. > > I like GPS. It is wonderful. I have an IFR-certified GPS in each of my > airplanes. It is not cheap though. > > The numbers from about five years back are as follows: > > Annual cost to operate LORAN -- $29M > > Annual cost to operate GPS -- $400M > > Cost to deploy GPS -- $10.5B > > Cost for WAAS was supposed to be -- $1B (it went way over budget) > > The costs have gone up substantially, especially for WAAS. > > The Europeans have it right with their system that will do WAAS by > transmitting the corrections via LORAN. The nice thing is that their > WAAS datalink acts as a backup area navigation. If their satellites go > down for whatever reason, you can still find your way to your > destination. The way that the FAA is going we will have no backup > navigation system. > > I do not advocate getting rid of GPS -- far from it. We need GPS. It is > just that it is monstrously more expensive than either VOR or LORAN for > navigation and it is easily jammed. The WAAS system is very poorly > designed. > > What it boils down to is that I *really* want the FAA to keep VOR > and/or LORAN navigation around. I don't want to find out that some bad > guy has laid hands on one of the $4000 Russian GPS jammers just as I am > making a precision VLP approach to minimums on some dark and stormy > night after the FAA has 'retired' the VOR and LORAN systems. Someone at > the FAA needs to get a clue about systems design. > > Oh yeah, I forget: > > "Hi, I'm from the FAA and I am here to help." > > "Here at the FAA we're not happy until you're not happy!" > > Brian Lloyd 6501 Red Hook Plaza > brianl(at)lloyd.com Suite 201 > +1.340.998.9447 St. Thomas, VI 00802 > > I fly because it releases my mind from the tyranny of petty things . . . > Antoine de Saint-Exupry > > > Try www.SPAMfighter.com for free now! ________________________________________________________________________________
Date: Jan 17, 2005
From: Rob Logan <Rob(at)logan.com>
Subject: Re: Dynon Efis
|July 24, 2002) at 01/17/2005 11:15:51 AM, Serialize by Router on mtasmtp1-clev/P/SERVER/PHILIPS-CLE(Release 5.0.11 |July 24, 2002) at 01/17/2005 11:16:17 AM, Serialize complete at 01/17/2005 11:16:17 AM > on initial takeoff and chandelle type maneuvers (such as a closed > pull-up, or first turn out of traffic), the unit had significant > acceleration errors and frequently showed erroneous bank angles. The $15k certified xbow 500 in a lancair will do the same. Its better than any spinning tungsten because the kalman filter level it soon after. (no caging) enough so I take mine IMC with a backup T&B. the trick is to fly GPS barring and track (or Chelton velocity vector) for the first 2mins. Rob ________________________________________________________________________________
Date: Jan 17, 2005
From: Rob Logan <Rob(at)logan.com>
Subject: Re: WAAS or Not
|July 24, 2002) at 01/17/2005 11:16:35 AM, Serialize by Router on mtasmtp1-clev/P/SERVER/PHILIPS-CLE(Release 5.0.11 |July 24, 2002) at 01/17/2005 11:17:11 AM, Serialize complete at 01/17/2005 11:17:11 AM > At airports located in high obstacle fields, the lowest minima will almost > always be via a non precision level flight segment approach. while this is true, a CNX80 loaded with 2.0 software or any Chelton will provide vertical guidance below MDA from FAF to MAP via a perfect to hit dirt (yea its shallow) GS. with a Chelton one can do a "VFR" approach with any angle GS (all the way to dirt) but I'd prefer to take the surveyed path up high. For those that have actually pushed mins, ground lighting is extremely important.. heck, I've gone missed on an ILS twice and then went to an airport with centerline lighting and made it.. Lighting is extremely important. This and another experience makes me note the type of lighting (RAIL) before any approach. The point the original author of the thread was trying to make before it was hijacked was: Does the shutdown of your entire navigator if one very hard to receive SV signal is lost, increase safety? wouldn't some information be better than none? Bob's been waiving the MDA, LPV minima flag for 3+ years to keep us legal, and that's *very* important. but these navigators offer real life advantages, and lets hope that can be improved too. Rob ________________________________________________________________________________
Date: Jan 17, 2005
aeroelectric-list(at)matronics.com
From: Neil K Clayton <harvey4(at)earthlink.net>
Subject: Source for Alternator B+ lead
I read that the alternator output (B+) lead should be #6 AWG and shielded. I can't find a source for shielded #6 cable. Could someone pls direct me? Is the shielding grounded? both ends? one end? what kind of connection? Thanks Neil ________________________________________________________________________________
From: BobsV35B(at)aol.com
Date: Jan 17, 2005
Subject: Re: WAAS or not
In a message dated 1/17/2005 10:55:11 A.M. Central Standard Time, jschroeder(at)perigee.net writes: I doubt if comparing the cost of installing and maintaining the ILS systems vs. the costs to the FAA of implementing WAAS can be done easily. Nor can we blame the loss of signal when not looking at the southern skies on the FAA, as Rob suggests. As Brian notes, the FAA bears little, if any of the cost of the basic GPS system. The architecture is designed for truly world-wide operations by the DOD - not for 95% reliability of navigation by us good GA users. I also believe that the Coast Guard is OPR for the Loran system. Good Points John, Personally, I am just a user and can't comprehend all of the subtleties of finance involved. I just note that it works great and has never failed me even once in over fifteen years of use. I think the fact that it is a worldwide system and relied upon by so many others besides aviation will assure it's being adequately available to all. I have no doubt that there are good reasons to keep the Loran in operation, but I sure hope we GA type do not have to use it at all. When I had my IFR approved LORAN set, it always failed me when I wanted it the most. Every time I was in precipitation, it told me it was unreliable. That has never happened when I was using GPS. I realize just one operators experience doesn't make a valid case for all, but it sure impressed me. All of those brainy techies tell me that with better static wicks, better grounding of aircraft components and a newer, and yet to be developed, antenna, the LORAN problems will be mitigated. I am not so sure that will ever work for us small plane devotees. The last "H" style antenna I saw was so big it could never be used in a Bonanza let alone an RV. I can go to the K-Mart and buy a GPS for one hundred dollars that will work in a torrential downpour and still give me excellent positional accuracy anywhere on the planet Earth. I hope the LORAN dies and pleasant and honorable death. Happy Skies, Old Bob AKA Bob Siegfried Ancient Aviator Stearman N3977A Brookeridge Airpark LL22 Downers Grove, IL 60516 630 985-8502 ________________________________________________________________________________
Date: Jan 17, 2005
From: Scott Bilinski <bilinski@kyocera-wireless.com>
Subject: Re: Source for Alternator B+ lead
You can buy shielding sleeve and shield any wire. I have seen it, but dont know where to get it. > > >I read that the alternator output (B+) lead should be #6 AWG and shielded. > >I can't find a source for shielded #6 cable. >Could someone pls direct me? > >Is the shielding grounded? both ends? one end? what kind of connection? > >Thanks >Neil > > Scott Bilinski Eng dept 305 Phone (858) 657-2536 Pager (858) 502-5190 ________________________________________________________________________________
From: "Werner Schneider" <glastar(at)gmx.net>
Subject: Re: Dynon Efis
Date: Jan 17, 2005
Hello Dan, sorry for the name mismatch. Thanks for the update, from whom did you get this message about BMA? I just can remember, that BMA had severe problems even in 30 deg turns until about a year ago. As the 1.10 is from December last years you did fly with the old version of the Dynon. Thx for the update Werner ----- Original Message ----- From: "D Fritz" <dfritzj(at)yahoo.com> Subject: Re: AeroElectric-List: Dynon Efis > > Werner, > I had one of the early units and updated the software once or twice, probably not up to the 1.10 version. I can't say for sure as I've sold the aircraft and last flew it in May '04. I did not compare these results with the Bluemountain unit since it was not installed in the Thorp. I'll have to wait until the Velocity is flying to do that test; however, I'm told Bluemountain went to great lengths to successfully avoid these errors through the use of GPS aiding in their filters. > > Dan Fritz > > > --------------------------------- > > ________________________________________________________________________________
Date: Jan 17, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Source for Alternator B+ lead
> > >I read that the alternator output (B+) lead should be #6 AWG and shielded. > >I can't find a source for shielded #6 cable. >Could someone pls direct me? > >Is the shielding grounded? both ends? one end? what kind of connection? Where did you read this? I'm aware of no practical reason for shielding any lead wires to or from the alternator. This was done as part of the ADF installation kit on Cessnas back in the 60s. However, the kit also included a noise filter capacitor on the alternator's b-lead . . . Turns out that all benefits of the kit were realized by adding the capacitor. Shielding added nothing but labor and cost. We didn't have the knowledge or tools to deduce this at the time so yet another baseless fabrication philosophy was plowed into the fertile ground of tradition. Leave the shielding off. You're going to be just fine. If you do have a noise problem, it won't be due to lack of shielding on the alternator's wiring. Bob . . . ________________________________________________________________________________
Date: Jan 17, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Odyssey Battery
>Bob: > >" but don't lust after an Odyssey > if your budget is limited. There are other practical choices." > >I researched all batteries, and don't know what has changed in 3 months, >but you can get a New PC-680 Odyssey on eBay delivered for about $50 + $15 >shipping. (add $12 for MJ=metal jacket). I know B&C specialties sells a >little 12 volt 16 amp for $120. Ouch! I don't know what brand, they don't >mention it. > >I looked at all options, Panasonic, Power Sonic, Dyna-Bat, Yuasa, Hawker >Genesis (retagged odyssey), Universal, B & B, and a few others and the >Odyssey it the best Value, has the lowest internal resistance, fits the RV >aircraft box and has the better M6 female terminals. > >The "OTHERS" SLA / AGM batteries with the same approx "FIT" cost around >$32-$69 (or more). Why would you want anything else? The El Cheap-O's do >work for most under normal conditions, but one who tried the Odyssey and >then a Cheap-O notice that the cheap battery did not crank as vigorously >as the Odyssey. Likely due to the higher internal resistance, Example is a >Panasonic LC-XB1220P 20 amp does not crank like a 16 amp Odyssey. Also the >"others" have the Tabs, not the nice internal threaded M6 terminals. You >can get some "Other" Batteries with a M5 female terminal but end up >costing about $70. > >The Odyssey is affordable and the best choice; *(Odyssey may-be $12-$20 >bucks diff from the cheapest battery, which has less performance. You get >what you pay for AND shop around.) > >Show me where I am wrong. :- ) There is nothing "wrong" with the Odyssey battery . . . and nothing "wrong" with the selection of any other battery. My caution about designing a premium battery into you airplane is based on the notion that BATTERY MAINTENANCE should include either (1) periodic testing for CAPACITY such that you KNOW the battery will support the e-bus for duration of fuel aboard or (2) periodic replacement of the battery IN SPITE of the fact that it still cranks the engine very nicely. Even if you do periodic CAP TESTS, you'll be swapping the battery out long before it fails to crank the engine. This means that you not only expend $time$ to do the testing, you still swap the battery out before it's "dead". If you use the cheapest battery and swap it out every annual, then you have zero $time$ for testing and you minimize the cost per operating hour for batteries. If one uses a premium battery, there is an underlying desire on the part of most owners to take advantage of the capability of the premium product . . . i.e. run that puppy 'til it croaks just like we do in our cars and most of our airplanes. It depends on what your time and equipment costs are worth. Run the gold-plated battery if you wish but track it for capability and ditch it when capacity falls below your established minimums. Or, run the copper-plated battery for one year and pitch it. This isn't a decision driven so much by battery performance as the economics of $time$. Run any battery you like but please do so with understanding of how that product fits into your operating and maintenance goals. Which one is the better VALUE five years down the road? Bob . . . > >Thanks George > >PS I note that the Max temp specification limit is 45c and 80c, for the >Odyssey PC-680 and PC-680MJ respectively. I guess the $12 bucks for the >extra layer may be good. Any idea of temp under a RV-7 cowl on the firewall? > ________________________________________________________________________________
Date: Jan 17, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: avionics master
> > >For what it's worth, I have had a switch suddenly go open for no >apparent reason (while it was on and supplying power). The failure was >permanent - it would no longer turn on even though it would physically >toggle from off to on and back. Had one do it on a Beechjet last week. In this case, the switch carried TOO LITTLE current and was NEVER operated except in case of emergency . . . the contacts of this $high$ Microswitch product simply went open. I hooked a power supply to it and caused it to carry 20A constant current for a few dozen operations . . . it "recovered" and will probably run well for another 10 years. Bottom line is that the most reliable system design philosophy with respect to switches is figure out a way NOT to have the switch there in the first place. But if you MUST, then USE IT periodically, like every flight. This is the other side of the coin for "advantages" of not having to fiddle with radio switches when there's an avionics master switch in place . . . every radio power switch exists in a non-operating, ageing mode. Bob . . . ________________________________________________________________________________
From: "Tinne maha" <tinnemaha(at)hotmail.com>
Subject: Type I Contactor
Date: Jan 17, 2005
Listers, My battery contactor is a Type I, the kind where two flat surfaces come together to supply current through the big wire & one of the flat surfaces is formed by the internal end of the post to which we bolt our ring terminals. I'm sure it works great unless one of the posts is rotated & the flat surfaces are no longer parallel, thus preventing the maximum amount of surface area to come into contact. Well, the other day when tightening a bolt on my battery contactor, the post rotated some. Can anyone suggest how I can be positive that the post is rotated back to the optimum position? Thanks, Grant Krueger ________________________________________________________________________________
From: James Freeman <flyeyes(at)mac.com>
Subject: Re: Dynon Efis
Date: Jan 17, 2005
On Jan 17, 2005, at 1:58 PM, Werner Schneider wrote: > > > Hello Dan, > > sorry for the name mismatch. > > Thanks for the update, from whom did you get this message about BMA? I > just > can remember, that BMA had severe problems even in 30 deg turns until > about > a year ago. (snip) Werner, I know from personal experience that's not accurate (not sniping, just trying to squelch a rumor). There have been _lots_ of rumors swirling around most of the EFII. I had one of the earliest EFIS-One boxes (plastic case) which initially had some issues but the in-flight inertial performance was quite good as early as summer of '02. After a software upgrade at that time, I was unable to confuse the EFIS in flight in a Cessna 150 or 337 (I did hook up temporary pitot and GPS inputs) I tried aggressive maneuvering (within the flight envelopes of the cessnas), level acceleration and deceleration, and multiple turns (7 or 8 consecutive 360 degree turns at various bank angles). I was able to consistently confuse the TSOd vacuum gyros installed in the airplanes, but not the EFIS. I have flown a few hours behind an early EFIS Lite in an RV8A, and it works very well, except that you can saturate the sensors in a full-deflection roll. I won't dispute that BMA probably shipped stuff a little too soon, but Greg has worked aggressively to make things right. I was very disturbed after Sam Buchanan had his problems, and flew with my box to Copper hill. Greg bench checked my box, and then went flying with me for more than an hour until I was satisfied that it was working properly. I think his biggest problem right now is production, and the current flight planning and engine monitoring software have significant room for improvement. James Freeman ________________________________________________________________________________
From: Brian Lloyd <brianl(at)lloyd.com>
Subject: Re: WAAS or not
Date: Jan 17, 2005
On Jan 17, 2005, at 11:42 AM, Wayne Sweet wrote: > The LORAN I flew with for a few years was, well, adequate, but lost > track > several times in the most inopportune times. I was delighted to remove > it > and install the first GPS. You had to understand its limitations. The addition of the mid-continent chains and the availability of receivers to track multiple chains eliminated the coverage and geometry problems. > Since then, zero lost tracks, zero problems with > the Apollo 2001, UPS GX50 and now the GNS430. I have had problems with GPS. > To use LORAN in conjunction with a GPS system is a bit bizarre. Actually, it makes perfect sense. They both provide reliable area navigation. GPS has better absolute accuracy and LORAN has astounding repeatability. They work at completely separate frequencies so that a problem that jams one will not affect the other. LORAN is almost impossible to jam because the signal is just so bloody powerful and the required antenna is huge, i.e. hundreds of feet, not something you will cart around in the back of your car. Unlike GPS, you can't carry a LORAN jammer in your briefcase. And as the Europeans have shown, you can combine the two systems and get something much better. You can easily fly an approach to VOR or NDB minimums using LORAN reliably and safely. That is why it makes such a good backup for GPS. > Never heard of a device that jams GPS signals. How does such equipment > interfere with signals from 25 satellites over a wide geographical > area? Since all the satellites share a single frequency, you just need a jammer on that frequency. Since the satellites are so far away (14,000 mi) and transmitting a not-very-powerful signal, someone in a C-172 with the lunchbox-sized Russian 5-watt jamming transmitter could wipe out GPS for the whole of the Los Angeles basin or the whole of the Bay Area. You just have to get high enough that the GPS antennas on the aircraft can see your jammer too. Because the jammer is so much closer, it will completely swamp the signal from the satellites. And an even more devious hack would be to transmit valid but bogus satellite transmissions. You could make a single aircraft fly anywhere you wanted it to just by forcing the signals it hears to be what you want them to be. Imagine taking a single airliner and change the signals it receives so that it flies off-course into higher terrain while all the receivers on the airplane show it tracking the approach. It could be done and if I can think of it ... BTW, the Russsian jamming transmitter was selling for $4000 a couple of years back. They were showing it off at the Tail Hook convention in Reno a couple years back. The whole point of this is not to rant but to help people understand just how fragile GPS is. The way it is currently designed, it cannot be depended on as sole-source navigation where such navigation is life-critical. It is just too easy to make it not work. Brian Lloyd 6501 Red Hook Plaza brianl(at)lloyd.com Suite 201 +1.340.998.9447 St. Thomas, VI 00802 I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry ________________________________________________________________________________
From: "Richard Suffoletto" <rsuffoletto(at)hotmail.com>
Subject: Encoder test
Date: Jan 17, 2005
This may be a dumb question... Is there any way to test an encoder to see if it is working? Other than making sure all wiring is correct and votages are where they should be and proper. My encoder will be difficult to reach (not impossible) when I put the top skin on so I wanted to check it before closing it in. I know I can have an Avionics shop come out and test it but that is a bit difficult due to my location... thanks richard ________________________________________________________________________________
Date: Jan 17, 2005
From: Jay Brinkmeyer <jaybrinkmeyer(at)yahoo.com>
Subject: Cat 5
Cat 5 cable is typically used for Ethernet networks running at 10 or 100 Mbps... More than you want to know here: http://www.lanshack.com/cat5e-tutorial.asp Jay > >Hi All- > > > >Can someone explain to me the significance of cat5 and or cat5e cable? > >What makes it special? When would I want to use it vs a bundle of plain > >old fashioned MS tefzel? > > ===== __________________________________ ________________________________________________________________________________
From: "Wayne Sweet" <w_sweet(at)comcast.net>
Subject: Re: WAAS or not
Date: Jan 17, 2005
I fly regularly with other pilots with GPS equipped aircraft and have not heard a single complaint about GPS signal loss. BTW, I was flying the LORAN (Apollo 618) when all the chains were up. Still lost track one night going into Columbia Airport in the Sierra foothills and departing Arlington, WA. The latter was the last straw. Lost track frequently in the southwest. Have flown across the U.S., down to the southwest and the northwest, never lost track with the GPS. Oh, on one of the initial test flights, did lose track on the Apollo 2001, but a reposition of the antenna solved the problem. Wonder how many other lost tracks in aircraft can be attributed to poor antenna location. Wayne ----- Original Message ----- From: "Brian Lloyd" <brianl(at)lloyd.com> Subject: Re: AeroElectric-List: WAAS or not > > On Jan 17, 2005, at 11:42 AM, Wayne Sweet wrote: > >> The LORAN I flew with for a few years was, well, adequate, but lost >> track >> several times in the most inopportune times. I was delighted to remove >> it >> and install the first GPS. > > You had to understand its limitations. The addition of the > mid-continent chains and the availability of receivers to track > multiple chains eliminated the coverage and geometry problems. > >> Since then, zero lost tracks, zero problems with >> the Apollo 2001, UPS GX50 and now the GNS430. > > I have had problems with GPS. > >> To use LORAN in conjunction with a GPS system is a bit bizarre. > > Actually, it makes perfect sense. They both provide reliable area > navigation. GPS has better absolute accuracy and LORAN has astounding > repeatability. They work at completely separate frequencies so that a > problem that jams one will not affect the other. LORAN is almost > impossible to jam because the signal is just so bloody powerful and the > required antenna is huge, i.e. hundreds of feet, not something you will > cart around in the back of your car. Unlike GPS, you can't carry a > LORAN jammer in your briefcase. > > And as the Europeans have shown, you can combine the two systems and > get something much better. You can easily fly an approach to VOR or NDB > minimums using LORAN reliably and safely. That is why it makes such a > good backup for GPS. > >> Never heard of a device that jams GPS signals. How does such equipment >> interfere with signals from 25 satellites over a wide geographical >> area? > > Since all the satellites share a single frequency, you just need a > jammer on that frequency. Since the satellites are so far away (14,000 > mi) and transmitting a not-very-powerful signal, someone in a C-172 > with the lunchbox-sized Russian 5-watt jamming transmitter could wipe > out GPS for the whole of the Los Angeles basin or the whole of the Bay > Area. You just have to get high enough that the GPS antennas on the > aircraft can see your jammer too. Because the jammer is so much closer, > it will completely swamp the signal from the satellites. > > And an even more devious hack would be to transmit valid but bogus > satellite transmissions. You could make a single aircraft fly anywhere > you wanted it to just by forcing the signals it hears to be what you > want them to be. Imagine taking a single airliner and change the > signals it receives so that it flies off-course into higher terrain > while all the receivers on the airplane show it tracking the approach. > It could be done and if I can think of it ... > > BTW, the Russsian jamming transmitter was selling for $4000 a couple of > years back. They were showing it off at the Tail Hook convention in > Reno a couple years back. > > The whole point of this is not to rant but to help people understand > just how fragile GPS is. The way it is currently designed, it cannot be > depended on as sole-source navigation where such navigation is > life-critical. It is just too easy to make it not work. > > Brian Lloyd 6501 Red Hook Plaza > brianl(at)lloyd.com Suite 201 > +1.340.998.9447 St. Thomas, VI 00802 > > I fly because it releases my mind from the tyranny of petty things . . . > Antoine de Saint-Exupry > > > Try www.SPAMfighter.com for free now! ________________________________________________________________________________
From: "Wayne Sweet" <w_sweet(at)comcast.net>
Subject: Re: Encoder test
Date: Jan 17, 2005
Always assume you WILL have to get to the avionics and make access an hatche(s) to provide such access. My plans called for riveting the bottom skin panel, but I realize that to access behind the instrument panel would be impossible for all but a 4 foot midget avionics tech., so that bottom skin was screws and nutplates, about 50 of them. It takes 30 minutes to remove it, then the fuel distribution system. Then I can sit on a creeper and get up behind the panel with complete access to all the stuff. I have updated the avionics several times and that one feature made it possible. Otherwise, no way. Wayne ----- Original Message ----- From: "Richard Suffoletto" <rsuffoletto(at)hotmail.com> Subject: AeroElectric-List: Encoder test > > > > This may be a dumb question... Is there any way to test an encoder to see > if > it is working? Other than making sure all wiring is correct and votages > are > where they should be and proper. My encoder will be difficult to reach > (not > impossible) when I put the top skin on so I wanted to check it before > closing it in. > > > I know I can have an Avionics shop come out and test it but that is a bit > difficult due to my location... > > thanks > > richard > > > Try www.SPAMfighter.com for free now! ________________________________________________________________________________
From: James Freeman <flyeyes(at)mac.com>
Subject: Re: Encoder test
Date: Jan 17, 2005
On Jan 17, 2005, at 5:34 PM, Richard Suffoletto wrote: > Is there any way to test an encoder to see if > it is working? snip > > I know I can have an Avionics shop come out and test it but that is a > bit > difficult due to my location... > snip Jim Weir wrote an article about making an encoder "test box" a few years ago, but I can't seem to find it on the web. Someone may have a copy stashed. If you are building at an airport, see if you can find someone with a well-equipped late model IFR airplane with the BF Goodrich Skywatch. It would be trivial to turn the skywatch on and see if it can see your transponder and (ground) altitude ________________________________________________________________________________
From: "Larry McFarland" <larrymc(at)qconline.com>
Subject: Re: Encoder test
Date: Jan 17, 2005
Richard, The encoder has to be tested by an authorized instrument repairman that can tag it for use in controlled airspace. There are methods available for you to do it, but I wouldn't get too excited about that. The system coupled with your altimeter will be tested to 20,000 ft the first time in an installation. Your Airworthiness Cert will require you have this done beforehand. Additionally, I'd recommend you look at making the forward top skin removable so you can check this system and so many others as often as you like. My forward top skin comes off in 10 minutes with my canopy tilted forward so that I can check the engine mount attachments and service the other wiring, plumbing etc. If you're interested in this, both the inspection process is in my journal 7 or 8 along with pictures of the removable forward top skin and how it was done. I've had it off probably 15 times since April of 2004. Site is www.macsmachine.com Good question. Larry McFarland - 601HDS Stratus with Ram Heads at 50 hours. Subject: AeroElectric-List: Encoder test > > > > This may be a dumb question... Is there any way to test an encoder to see > if > it is working? Other than making sure all wiring is correct and votages > are > where they should be and proper. My encoder will be difficult to reach > (not > impossible) when I put the top skin on so I wanted to check it before > closing it in. > > > I know I can have an Avionics shop come out and test it but that is a bit > difficult due to my location... > > thanks > > richard ________________________________________________________________________________
Date: Jan 17, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Type I Contactor
> >Listers, > >My battery contactor is a Type I, the kind where two flat surfaces come >together to supply current through the big wire & one of the flat surfaces >is formed by the internal end of the post to which we bolt our ring >terminals. I'm sure it works great unless one of the posts is rotated & the >flat surfaces are no longer parallel, thus preventing the maximum amount of >surface area to come into contact. > >Well, the other day when tightening a bolt on my battery contactor, the post >rotated some. Can anyone suggest how I can be positive that the post is >rotated back to the optimum position? You can't without taking the lid off and then it's trash anyhow. Bob . . . ________________________________________________________________________________
Date: Jan 17, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Encoder test
> > > >This may be a dumb question... Is there any way to test an encoder to see if >it is working? Other than making sure all wiring is correct and votages are >where they should be and proper. My encoder will be difficult to reach (not >impossible) when I put the top skin on so I wanted to check it before >closing it in. > > >I know I can have an Avionics shop come out and test it but that is a bit >difficult due to my location... No real easy way. I use an Airsport transponder receiver and display which you can view at: http://www.airsport-corp.com/ For most transponders, you can lay a 115 vac drillmotor on a stool right under the transponder antenna. Tie the switch ON with a rubber band. Brush noise from the motor will cause the transponder to "reply" continuously. You can read the altitude being reported directly from the Airsport receiver's panel. Put a small hand vacuum pump on the static system. These work well: http://www.jcwhitney.com/autoparts/ProductDisplay/c-10101/s-10101/p-161626/mediaCode-ZX/appId-385312 I use a pint mason jar with a couple of hose fittings soldered to the lid for a vacuum accumulator. A brass needle valve from an aquarium supplies store provides a precision leak-down valve to control rate of descent. Plumb a calibrated altimeter into this system and you can do your own static system checks with the same degree of precision as the $high$ guys. Bob . . . ________________________________________________________________________________
From: Bikcrzy(at)aol.com
Date: Jan 18, 2005
Subject: Fuse-link
Hello List, I need an explanation why the wire coming off the master switch connecting to the main power bus on the Z-11 generic light aircraft system drawing needs a fuse-link instead of a standard fuse? Is it because the fuse-link will handle spikes better than a fuse? I don't see any special path that would require a break before a fuse? There probably is an easy answer but this stuff is somewhat new to me. Thanks in advance. John Robinson RV-7A. ________________________________________________________________________________
From: "Paul McAllister" <paul.mcallister(at)qia.net>
Subject: Re: Encoder test
Date: Jan 17, 2005
Richard, You might want to re think access. The avionics shop will need to adjust the offset and gain to match your altimeter. My shop let me take in the encoder and altimeter separately and then they performed a leak test latter. If you really have to bury it inside your aircraft then this might me an option. My encoder drifted out of calibration (an ACK30) 5 months latter, so they do fail sometimes. Paul ________________________________________________________________________________
Date: Jan 18, 2005
From: Mickey Coggins <mick-matronics(at)rv8.ch>
Subject: Re: Type I Contactor
I think this was discussed recently, but I can't find it in the archives. Does anyone have a good source for the type II battery contactors? Thanks, Mickey > Replace it with a type II? -- Mickey Coggins http://www.rv8.ch/ #82007 Wiring ________________________________________________________________________________
From: "Glen Matejcek" <aerobubba(at)earthlink.net>
Subject: cat 5
Date: Jan 18, 2005
Thanks Jay, that was just what I was looking for! Glen Matejcek aerobubba(at)earthlink.net ________________________________________________________________________________
Date: Jan 18, 2005
From: Ken <klehman(at)albedo.net>
Subject: Re: Fuse-link
clamav-milter version 0.80j on juliet.albedo.net Hi John Good question. Basically the answer is that fuse are fast acting and circuit breakers are very slow acting. If you put a fuse in there (even a large one) it will pop before the downstream Alt Field circuit breaker can open in an OV (overvoltage) situation. I don't think that is a major problem but then you might as well not install the CB, and after an OV occurrence, you'd have to install a new fuse if you wanted to restart the alternator to check that it was a real OV. Since real OV's are pretty rare I think either approach might be reasonable.... Ken Bikcrzy(at)aol.com wrote: > >Hello List, > >I need an explanation why the wire coming off the master switch connecting >to the main power bus on the Z-11 generic light aircraft system drawing needs >a fuse-link instead of a standard fuse? Is it because the fuse-link will >handle spikes better than a fuse? I don't see any special path that would require >a break before a fuse? There probably is an easy answer but this stuff is >somewhat new to me. Thanks in advance. John Robinson RV-7A. > > > > ________________________________________________________________________________
From: Brian Lloyd <brianl(at)lloyd.com>
Subject: Re: WAAS or not
Date: Jan 18, 2005
On Jan 17, 2005, at 9:41 PM, Wayne Sweet wrote: > > > I fly regularly with other pilots with GPS equipped aircraft and have > not > heard a single complaint about GPS signal loss. BTW, I was flying the > LORAN > (Apollo 618) when all the chains were up. Still lost track one night > going > into Columbia Airport in the Sierra foothills and departing Arlington, > WA. > The latter was the last straw. Lost track frequently in the southwest. > Have flown across the U.S., down to the southwest and the northwest, > never > lost track with the GPS. I put almost 3000 hours on my Arnav R-40 IFR-certifed LORAN in my Comanche before replacing it with an Apollo GX-60. I flew a lot of hard IFR using that LORAN. I overlaid the LORAN data atop of every VOR and NDB approach I flew. The LORAN was much more accurate than either of those and made shooting those approaches safer. LORAN wasn't a panacea tho'. I found it had a geometry problem at the colorado river E of Los Angeles no matter what I did and I lost it once in severe p-static in a snowstorm over the Atlantic. That p-static also took out my HF transceiver and my VHF transceiver. There was a multi-chain receiver that was built for heavy iron. It would navigate using all the chains (GRIs) and all the secondaries it could hear, not just the single primary and two secondaries that most aviation LORAN receivers used. It did not suffer from the availability problems because it worked around the problems of geometry and propagation. Think of it as the LORAN equivalent of the 12-channel parallel GPS receiver. If someone started building LORAN again you can bet that they would build a multi-chain receiver since the processing power needed to make it work is now cheap. I am not arguing the advantages of LORAN vs. GPS. I am arguing that LORAN can be used to deliver WAAS data to your GPS receiver AND if the GPS system goes down, your LORAN can be used as an area navigation system to get you to your destination safely. The GPS system right now depends on the same technology to deliver the WAAS data as it does to deliver position information and the WAAS channel delivers only WAAS data and nothing else. Through minor modifications the Europeans are going to take their existing LORAN system and have it transmit the WAAS data at a cost much, much lower than we paid for a satellite-based WAAS that provides no other backup. So the sort version is, the European system will provide all the advantages of our system at a lower cost AND their WAAS channel will provide backup navigation. That sounds a whole hell of a lot better system analysis and design to me. Brian Lloyd 6501 Red Hook Plaza brianl(at)lloyd.com Suite 201 +1.340.998.9447 St. Thomas, VI 00802 I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry ________________________________________________________________________________
Date: Jan 18, 2005
From: Rob Logan <Rob(at)logan.com>
Subject: Re: WAAS or Not
|July 24, 2002) at 01/18/2005 11:07:54 AM, Serialize by Router on mtasmtp1-clev/P/SERVER/PHILIPS-CLE(Release 5.0.11 |July 24, 2002) at 01/18/2005 11:08:20 AM, Serialize complete at 01/18/2005 11:08:20 AM > At airports located in high obstacle fields, the lowest minima > will almost always be via a non precision level flight segment while this is true, a CNX80 loaded with 2.0 software or any Chelton will provide vertical guidance below MDA from FAF to MAP via a perfect to hit dirt (yea its shallow) GS. with a Chelton one can do a "VFR" approach with any angle GS (all the way to dirt) but I'd prefer to take the surveyed path up high. For those that have actually pushed mins, ground lighting is extremely important.. heck, I've gone missed on an ILS twice and then went to an airport with centerline lighting and made it.. Lighting is extremely important. This and another experience makes me note the type of lighting (RAIL) before any approach. The point the original author of the thread was trying to make before it was hijacked was: Does the shutdown of your entire navigator if one very hard to receive SV signal is lost, increase safety? wouldn't some information be better than none? Bob's been waiving the MDA, LPV minima flag for 3+ years to keep us legal, and that's *very* important. but these navigators offer real life advantages, and lets hope that can be improved too. Rob ________________________________________________________________________________
Date: Jan 18, 2005
From: Rob Logan <Rob(at)logan.com>
Subject: Re: Dynon Efis
|July 24, 2002) at 01/18/2005 11:09:17 AM, Serialize by Router on mtasmtp1-clev/P/SERVER/PHILIPS-CLE(Release 5.0.11 |July 24, 2002) at 01/18/2005 11:09:39 AM, Serialize complete at 01/18/2005 11:09:39 AM > on initial takeoff and chandelle type maneuvers (such as a closed > pull-up, or first turn out of traffic), the unit had significant > acceleration errors and frequently showed erroneous bank angles. The $15k certified xbow 500 in a lancair will do the same. Its better than any spinning tungsten because the kalman filter level it soon after. (no caging) enough so I take mine IMC with a backup T&B. the trick is to fly GPS barring and track (or Chelton velocity vector) for the first min. Rob ________________________________________________________________________________
From: "Leo J. Corbalis" <leocorbalis(at)sbcglobal.net>
Subject: Re: Encoder test
Date: Jan 18, 2005
If you enjoy drilling out rivets carry on. The tech doesn't have contortionist as part of his job skills. If it's inaccible it will break. MURPHY'S LAWS RULE !!!! Leo Corbalis archive Original Message ----- From: "Richard Suffoletto" <rsuffoletto(at)hotmail.com> Subject: AeroElectric-List: Encoder test > > > This may be a dumb question... Is there any way to test an encoder to see if > it is working? Other than making sure all wiring is correct and votages are > where they should be and proper. My encoder will be difficult to reach (not > impossible) when I put the top skin on so I wanted to check it before > closing it in. > > > I know I can have an Avionics shop come out and test it but that is a bit > difficult due to my location... > > thanks > > richard > > ________________________________________________________________________________
Date: Jan 18, 2005
From: D Fritz <dfritzj(at)yahoo.com>
Subject: Re: Dynon Efis
Werner, All information I have about the BMA units is gleaned from the discussion pages on their web site - I recall their acceleration/attitude problems as having been well earlier than a year ago, but they've apparently solved them nevertheless. I did some research and the most recent software I flew with my Dynon was 1.09. Also, I had the original, D-10, hardware; they have since improved their hardware to a D-10A unit and I've not seen it in action yet. Dan Fritz --------------------------------- ________________________________________________________________________________
From: DWENSING(at)aol.com
Date: Jan 18, 2005
Subject: Re: Encoder test
In a message dated 1/18/05 12:02:42 AM Eastern Standard Time, b.nuckolls(at)cox.net writes: > I use a pint mason jar with a couple of hose fittings soldered > to the lid for a vacuum accumulator. A brass needle valve from > an aquarium supplies store provides a precision leak-down valve > to control rate of descent. A needle valve from a model airplane carburetor also works well. > > Plumb a calibrated altimeter into this system and you can > do your own static system checks with the same degree of > precision as the $high$ guys. > > Yes, we but can't certify it and make the log book entry. Correct? Dale Ensing ________________________________________________________________________________
Date: Jan 18, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Encoder test
> >In a message dated 1/18/05 12:02:42 AM Eastern Standard Time, >b.nuckolls(at)cox.net writes: > > > > I use a pint mason jar with a couple of hose fittings soldered > > to the lid for a vacuum accumulator. A brass needle valve from > > an aquarium supplies store provides a precision leak-down valve > > to control rate of descent. > > A needle valve from a model airplane carburetor also works well. > > > > > Plumb a calibrated altimeter into this system and you can > > do your own static system checks with the same degree of > > precision as the $high$ guys. > > > > > Yes, we but can't certify it and make the log book entry. Correct? Of course not . . . Bob . . . ________________________________________________________________________________
Date: Jan 18, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Type I Contactor
> > >I think this was discussed recently, but I can't find >it in the archives. Does anyone have a good source >for the type II battery contactors? > >Thanks, >Mickey No "good" ones. These are expensive. I used to handle them for Lancair IVP builders. See data sheet for 6041H105 contactor at: http://www.aeroelectric.com/Reference_Docs/Eaton Last time I sold one (about 5 years ago) it was about $175. Bob . . . ________________________________________________________________________________
Date: Jan 18, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Fuse-link
Good explanation Ken. The fusible link is a VERY slow acting fuse that protects wire from fuseblock/bus up to the circuit breaker. If one elects to run a 700-2-3 battery master, then a pullable breaker is still indicated for doing battery only ground maintenance and disabling the alternator. Bob . . . >Hi John > >Good question. Basically the answer is that fuse are fast acting and >circuit breakers are very slow acting. If you put a fuse in there (even >a large one) it will pop before the downstream Alt Field circuit breaker >can open in an OV (overvoltage) situation. I don't think that is a major >problem but then you might as well not install the CB, and after an OV >occurrence, you'd have to install a new fuse if you wanted to restart >the alternator to check that it was a real OV. Since real OV's are >pretty rare I think either approach might be reasonable.... > >Ken > >Bikcrzy(at)aol.com wrote: > > > > >Hello List, > > > >I need an explanation why the wire coming off the master switch connecting > >to the main power bus on the Z-11 generic light aircraft system drawing > needs > >a fuse-link instead of a standard fuse? Is it because the fuse-link will > >handle spikes better than a fuse? I don't see any special path that > would require > >a break before a fuse? There probably is an easy answer but this stuff is > >somewhat new to me. Thanks in advance. John Robinson RV-7A. > > > > > > > > > > >-- >Checked by AVG Anti-Virus. > > >-- incoming mail is certified Virus Free. >Checked by AVG Anti-Virus. Bob . . . -------------------------------------------------------- < Throughout history, poverty is the normal condition > < of man. Advances which permit this norm to be > < exceeded -- here and there, now and then -- are the > < work of an extremely small minority, frequently > < despised, often condemned, and almost always opposed > < by all right-thinking people. Whenever this tiny > < minority is kept from creating, or (as sometimes > < happens) is driven out of a society, the people > < then slip back into abject poverty. > < > < This is known as "bad luck". > < -Lazarus Long- > <------------------------------------------------------> http://www.aeroelectric.com ________________________________________________________________________________
Date: Jan 18, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Fix for radio noise
> > >I thought I would post the results of noise fix. I installed both mag >filters. (tedious) and fixed the noise. charlie heathco ATL. Thank you Charlie. For other folks on the list, Charlie called a couple of weeks ago complaining of magneto noise in radio. He had already wired per Z-figures and was reasonably sure spark plug harnesses were okay. I suggested magneto p-lead noise filters. He's now reporting success with the noise problem. This is the first time since I've been publishing the 'Connection that I've become aware of a mag noise problem so intractable as to require the p-lead filters in addition to ordinary shielding. Bob . . . ________________________________________________________________________________
Date: Jan 18, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Z13a Pre-flight alt test procedure?
> > >Bob, using Z13A, what would the approved pre-flight check for the Primary >Alt and SD8 be? It's normally off, with the primary alt normally on. Bus >voltage over 13+ would indicate that the primary is working so would you >shut it off and turn the SD8 on and check the battery bus voltage again. If >so, there is that Alt off while running load dump thing again. (?) > >What would the approved preflight sequence look like? If you have an EXTERNALLY regulated alternator, you can turn this puppy ON or OFF at any time without risk to alternator or other components in the aircraft. So, during magneto/ignition run-up, turn the aux alternator ON and main alternator OFF to observe that the alternator output loadmeter comes up. At the usual mag/ign run up speeds (1800 rpm) you're going to get an alternator speed of about 2500 rpm. According to B&C data at: http://bandc.biz/Sd-8.pdf . . . one can expect only 4 to 5 amps from the alternator which means it may not support present system loads. The bus voltage may sag but ignore this. If the alternator comes up at all, it's probably fine. Then turn the main alternator ON and aux alternator OFF and continue with the rest of the pre-flight check. If you have an internally regulated alternator, I would wait until you've taxied out to approach end of runway and before you advance the throttle for magneto/ignition check, turn aux alternator ON and main alternator OFF with engine at idle RPM. I presume also that you've installed the recommended b-lead protection transorb. Run rpm up and see that aux alternator loadmeter shows some activity. Reduce rpm to idle before bringing main alternator back ON and turning aux alternator OFF. Bob . . . ________________________________________________________________________________
Date: Jan 18, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Installing a DAVTRON Outside Air Temp instrument.
> > >I have installed a Davtron OAT gauge 307FC - on the instrument panel. See >A.C.S. catalogue, page 353. I would like to wire it now for mounting just >inside the inner inspection plate of the right wing (RV-9A). I would like >to cut the red/black wires for an AMP terminal block in the wing root, as >well as one additional knife/disconnect connection. > >My question. Would the two connections compromise the capability of the >instrument as well as the accuracy of the gauge? I live in Northern >Ontario. OAT is a significant question. Thanks. I believe the Davtron temp sensor is a solid state 10mv/degreeK device that tolerates long wires and connectors very nicely. Just for warm fuzzies, check your installation with an ice cube. The OAT should read very close to 32F/0C as installed using an ice cube to cool the installed sensor. Bob . . . ________________________________________________________________________________
Date: Jan 18, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Aircraft Development Expense
> > > > >> When I hear that designs are fixed due to the HUGE cost of FAA > >> certification, I don't believe it. The FAA is a bureaucracy but they > >> respond to standard engineering documents. > >I disagree: check out this month's Aviation Consumer on page 20 to see just >how this mindset is holding us back.. >SCott in VAncover I can personally attest to the differences in today's certification efforts as compared to 30 years ago. The differences are HUGE. It can take as long as 2 years to get a TSO'd part on a type certificated airplane. The quantity of no-value-added paperwork is aggravated by the fact that step by step approvals can have up to 90 days of turn-around time to get document submissions back from your FAA handler. As engineers, we spend about as much time in communion with our FAA watchdogs as we do in real design work. Further, it's so difficult to get a product to market that once certification is achieved, any progressive product improvements are all but impossible to incorporate. We've learned a lot in the past 30 years . . . things that could save weight and dollars in for our customers but just won't happen because of poor return on investment for the effort. Type certificated aircraft are frozen in time, OBAM aircraft evolve with the marketplace. I can't imagine why anyone would buy a new C-172 when an RV runs circles around it for both performance and price for half the dollars. Further, if you want/need to modify it, the task is done with a tiny fraction of $time$ compared to the certified ship. Bob . . . ________________________________________________________________________________
Date: Jan 18, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Modified Z-12 comments
> >I have a builder buddy (not on list) that is in the process of wiring his >plane using a slightly modified Z-12 with the addition of an aux battery >wired in per Figure 17-6. He's asked me for my comments on the >"modifications" he made and I'm not too sure how to respond. It a "I would >not do it this way, but that doesn't mean he shouldn't", kinda thing. First, Z-12 was never intended as a solution for a new design. It's a snap-shot of what the certified world is doing to add the SD-20 alternator to an existing airplane that doesn't have an e-bus nor does the owner/operator have the option of making changes with out expending a lot of time and dollars. If one is going to have dual batteries with two very capable alternators, then Z-14 is the ticket. >The main parts of Z-12 are not changed other than adding the second battery >and contactor I mentioned above. The thing he changed was in the switching >of the main/aux batteries and the main/aux alternators. E-bus is run off >the main battery only - just like in Figure 17-6. > >For the switches, he has used 2 DPST switches - one simultaneously activates >the main battery and main alternator together, and the second activates the >aux battery and the aux alternator together. There is no single "master" >switch in this combination, but there is also no way to run the aux >alternator from the main battery only. There are still two ways to send >power to the main bus - main on, aux on (or both of those on), and the e-bus >can be powered from the main battery via a separate e-bus switch. However, >there is now no way to isolate an alternator only from it's respective >battery. Did he explain why he departed from the recommended switch configuration? As shown, Z-12 allows the pilot to shut off the main alternator while leaving the battery on line (S700-2-10 progressive transfer switch). Except for the e-bus replacing an "avionics bus" this is the way the C-210 is wired. >Now, for you "theory" folks out there...is this an acceptable design >modification? It certainly saves panel switch space (two vs 4 switch >holes), but I'd like to hear some of the "knows more than me" crowd's >opinions on coupling the battery and alt switches together. I'm also mystified why he installed two batteries when there are two robust alternators. If he's using B&C hardware throughout, he already has the most reliable alternators on the market so it's VERY unlikely that he'll find himself in a battery-only modus operandi. There are no "acceptable" or "unacceptable" modifications. The "best" modifications are accomplished with rational attention to failure mode effects analysis, parts count reduction and operational simplicity. If you would ask him to detail the reasons for whatever changes he made, only then can I or any one else on the List offer analysis of the reasoning. Several times a month I get drawings in the mail where a builder says, "Did everything you recommended in Figure Z-xx with just a few changes." The builder almost never states what the changes were and what perceived failure mode drove the changes. I simply don't have time to second guess the builder's desires or intentions. Ask your friend to tell us why two batteries and then, given that there are two robust alternators, why not Figure Z-14? Bob . . . ________________________________________________________________________________
Date: Jan 18, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Load dump and shutdown procedures
> >With all the discussion on load dump ever wondered why now and not 50 years >ago? Except for Bonanza/Baron style architecture (separate switches for alternator and battery-master, there's no great risk of generating a load-dump event by manipulation of controls. >One reason is then (and now) I have learned and then taught that the >alternator was turned on only after the engine was started and both the >battery and the alternator was only turned off AFTER the engine was >completely stopped. > >Recently I have seem and observed first hand cases where the ammeter was >checked during runup by turning the alternator off. Also the alternator and >master were turned off before shutting down the engine. > >The latter procedure assures load dump and the former prevents load dump. > >Any one know when the latter procedure became popular in some circles??? > >The above does not include emergency or failure conditions. For the most part, it doesn't matter on certified ships. None that I know of have alternators with built in regulators. There's no overpowering reason for either of the techniques cited to take presidence over the other. Bob . . . ________________________________________________________________________________
Date: Jan 18, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Load dump and PM alternators
><Gilles.Thesee@ac-grenoble.fr> > >Hi Eric and all, > >Please pardon me for having followed the load dump thread with a casual eye. > > > Load dump is an issue with any source of power that uses a rotating > > conductor in a magnetic field. By the way, overvoltage and load dump are > > related in that they both have associated overvoltages. Load dump is a > > strictly transient OV condition caused by disconnecting a load, but an > > overvoltage condition can be caused by a failed regulator or other causes > > and may be long term. Both need to be addressed. > > > >Question : is the load dump issue the same for permanent magnet alternators >? At first glance I would say there are differences, but would one of you >experts tell me if I have to reconsider my "ordinary" crowbar OV module >setup ? No, only the internally regulated alternators with Figure Z-24 wiring. There are no special concerns for alternators with external regulators or permanent magnet alternators. Bob . . . ________________________________________________________________________________
From: dsvs(at)comcast.net
Subject: P-Mag Wiring
Date: Jan 18, 2005
Bob, I am in the process of setting up my electrical system and have a "Switch" question. The P-mag needs a P-lead type switch and a power switch. To save space I would like to use one switch for both operations. A three position switch could be used for this if one with the needed configuration is available. do you know of such a switch? Thanks. Don Bob, I am in the process of setting up my electrical system and have a "Switch" question. The P-mag needs a P-lead type switch and a power switch. To save space I would like to use one switch for both operations. A three position switch could be used for this if one with the needed configuration is available. do you know of such a switch? Thanks. Don ________________________________________________________________________________
From: "Eric M. Jones" <emjones(at)charter.net>
Subject: Re: Aircraft Development Expense
Date: Jan 18, 2005
> >> When I hear that designs are fixed due to the HUGE cost of FAA certification, I don't believe it. The FAA is a bureaucracy but they respond to standard engineering documents. Call me hopelessly optimistic. I have dealt a bit with the FAA and have found them reasonable. But I have dealt a whole lot more with the FDA--and they can't be so very different in terms of paperwork and complications. I have dealt with UL, ETL, and a dozen test labs. I have also dealt with corporate bureaucrats who would have been ratted out to the FBI and shot as saboteurs in WWII.... But I digress....Here's the plan: Since the economic well-being of ...oh, pick a name out of the air...Raytheon, depends greatly on an efficient FAA certification process, it would behoove Raytheon management to get their state representatives to wake up and smell the av-gas. Or else. But apparently it does not interest anybody in management enough to speed up the process. For that matter you could organize to vote the FAA out of existence if they are really holding up the process. Keep the lawyers and anyone else who benefits from lengthening the process out of it. Okay, so I'm much too optimistic---but I think this is a solvable problem. I knew a young Chinese engineer who remarked that gourmet chefs usually failed in trying to run Chinese restaurants. But he and his other engineer friends looked upon it as input-process-and-output. And they hire gourmet chefs. Okay--Hopelessly Naive.... Regards, Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge MA 01550-2705 Phone (508) 764-2072 Email: emjones(at)charter.net ________________________________________________________________________________
Date: Jan 18, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: LOAD dump comments
> > > > > -----Original Message----- > > From: "Paul Messinger" <paulm(at)olypen.com> > > To: > > Date: Fri, 7 Jan 2005 09:04 (CDT) > > Subject: AeroElectric-List: LOAD dump comments > > > > > > Eric has a packaged assy that is easier to > > install but a few more $$. > > > > > > Its worse if you have the standalone OVP and an internally regulated > > alternator IF the OVP trips during flight; here is what happens. (This > combo > > is not recommended as I understand by Vans. And I agree! at least with any > > type of crowbar OVP device.) > >Ok, so let me get this right. > >If I add the "Whackjack" http://www.periheliondesign.com/whackjack18.htm >to my currently installed Vans 60amp internally regulated alternator and >Bob Nuckolls OV protection setup which includes a crowbar, then I will be >ok and I won't fry my alternator. > >I don't mind paying a little extra for a part, if I know it is going to do >the job, because somebody has done the test and knows that it will do the >job. You guys spent some time working on this. > >What about it Bob Nuckolls, is this going to do what we need it do? Does >it have your blessings? You can do anything on your OBAM aircraft that you wish and certainly without my blessings. Van's hasn't a clue as to why any particular ov protection system should or should not be incorporated. In fact, I don't believe any of the factory ships have ov protection of any kind. Crowbar ov protection has been flying for over 15 years in what must no be 2000-3000 airplanes carrying B&C's LR series regulators. Last time I talked with Femi (Zeftronics guy) at OSH about ten years ago, he was impressed with the low parts count and improved performance of crowbar over then popular ov relays. I believe several of his certified after-market regulators now feature crowbar ov protection. Crowbar ov protection is included in B&C's SD-20 installations on certified ships. I'll bet there's over 1000 of those installations flying by now. It still amuses me that some folks are happy to have circuit breakers interrupt current to a faulted wire but get their shorts in a bunch when we deliberately fault a wire downstream of a breaker to corral a runaway alternator. The SAME fault currents flow in both instances. Yes, it's certainly hundreds of amps. But irrespective of WHY the breaker or fuse opens, the event terminates in milliseconds, effects on the rest of the system are the same and of no particular significance. The Beechjet I've been working on for the last month experiences a 1000+ amp inrush when the a/c motor is switched on. Yes, there are trashy little gremlins launched into the system every time . . . but none exceed DO-160 expectations and 750+ Beechjets have been living happily with this condition for over 30 years. So when folks start tossing around gawd-awful current numbers and attributing high-risk consequences, please be both skeptical and calm. Probability is that these conditions have been considered as part an parcel of the system design and do not represent a reason to start ripping things out of your airplane. It isn't the crowbar ov module that causes the load-dump event on an internally regulated alternator. Note that Van's customers reported the problem after turning the system OFF and ON while the alternator was loaded. Results would have been the same whether or not a crowbar ov module or ANY OTHER ov protection system were installed. The simple-ideas underlying this discussion are concerned with a narrow range of instances where an internally regulated alternator wired for aircraft service per Figure Z-24 and IS NOT CAPABLE of standing off its own load-dumps. Let's focus on that issue and deduce the elegant solution for risk mitigation to the alternator. Figure Z-24 has been in print for many years and I'll suggest that most alternators incorporated in that configuration ARE capable of standing off their own load-dumps. I suspect this includes the population of alternators that are OEM configuration junk-yard take-offs with original regulators installed. There's been a boat-load of wild-eyed traffic on this topic on the list, and directly to B&C and myself over the past several weeks. This is not a big deal folks. Just a little clear air turbulence. The risks are low, the solution is simple and not worthy of great concerns. Bob . . . ________________________________________________________________________________
Date: Jan 18, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Load Dump
> >Bob > >I have some procedure questions. > >I have my plane wired per Z14. In the event of a low volt warning. Do I just >turn on the crossfeed contactor? or do I pull the circuit breaker going to >the B&C regulator and then turn on the crossfeed contactor. If your master switches are 2-10 then simply turn off the alternator on the 'dead' side and close the crossfeed contactor. If the main alternator fails, then your COMBINED bus loads must be reduced to 20A or less. Optionally, you could simply shut down the 'dead' side and treat the working side as an endurance mode operation thus saving all battery energies for approach to landing. >Is there any problem if the crossfeed contactor is accidentally turned on >with both system working properly? It doesn't hurt anything. If the SD-20 voltage is set higher than the main alternator, it might cause the loadmeter on the SD-20 to peg but this isn't a big deal if you catch it in a few minutes. I presume you have a CROSSFEED ON indicator light? Bob . . . ________________________________________________________________________________
Date: Jan 18, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Load dump and shutdown procedures
> >I totally agree. The auto alternator was designed to NEVER be disconnected >from the battery. Once you add the variable of battery on/off you open >another can of worms. Its not that it cannot be done just it was never a >design requirement for autos. I'm not sure this is true. The load-dump phenomenon is not new. It's been around since day-one with all alternators but particularly the internally regulated devices. The automotive industry is far more cognizant of design induced failures than the aircraft industry. Little glitches can generate recall and/or maintenance events numbering in the MILLIONS where we produce perhaps 50 or 75 of any one airplane every year. I'd bet a dollar to a donut that most internally regulated alternators are designed to withstand their own load-dump events. Bob . . . ________________________________________________________________________________
Date: Jan 18, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: RE: Digital Photos
> >Bob, > >What do you use for camera/lense and any special settings for the photos you >provide. We (at least me) would appreciate some clues on how to get >digitals with the same sharpness and fine detail. I use a Cannon C-5050 at the present time. This is the third digital camera I've owned. The C-5050 is a technically great machine but not ready for prime time. On a ferry trip from Puerto Rico to Culebra last winter, two or three little drops of salt water got through the zipper on my camera case when a wave broke over the bow. After a couple of hours, I could see signs of moisture on the inside surface of the LCD screen cover. Ever since, it acts up in humid conditions. I keep it stored in a plastic canister loaded with silica-gel and it always works for a few hours after I take it out on the road. But during a trip to San Antonio last spring, it started fussing after a few days. I could still shoot in the viewfinder mode without flash or LCD screen but all the really nice features were hosed. This camera will shoot through my binocular microscope to produce images like: http://www.aeroelectric.com/Pictures/HiRes1.jpg Would you belive this is a "failed" switch contact? Event without the microscope, it offers excellent close focus capability like: http://www.aeroelectric.com/Pictures/sm_switch_cutaway.jpg This switch is about .6" long and suffered the "failed" contact illustrated above. Except for the vulnerability to moisture ingress, I've been very satisfied with this camera. Due to it's "crippled" condition, I'll probably not sell it when I upgrade. My next purchase will probalby be the digital version of the Cannon EOS with interchangeable lenses. It remains to be seen how well that camera works through the microscope so I'll keep the C-5050 around until it croaks completely. I used digital photography extensively both on works for the 'Connection and for my job at RAC. Virtually all my memos and reports are liberally illustrated. It's so easy, there's no reason not to do it. Along with a camera, you need a minimalist editing and captioning program. Take a look at LView Pro. http://www.lview.com/index1024.htm It's very intuitive and easy to use. Bob . . . ________________________________________________________________________________
Date: Jan 18, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Load dump and shutdown procedures
> > > >>In my opinion internally regulated alternators have NO place in > aircraft regardless of availability etc. Bob used to have the same > opinion but I suspect he had to cave in to the widespread use and at > least attempt to make them safe to use.<< > >Your comments are well placed. But the problem is not "internally >regulated" per se . . . just internally regulated by a device that was >designed for a vehicle that could be pulled over and parked on the side of >the road. > >We have developed an internal regulator that has none of the problems you >describe and is designed to avoid the single point failure modes, etc, >that are inherent in the automotive incarnation of the integrated >alternator/regulator. I think it's simpler still George. The internal regulator is not an automatic negative irrespective of the vehicle it's used in. The prudent designer needs to be aware of limits in all system components and compare those with known stresses. I have to belive that ND and any other alternator designers have been aware of the effects of load-dump for a very long time. They've learned how to live with it harmoniously just as your own design has been crafted to well considered requirements. This whole tempest-in-a-teapot bubbled up for mostly wrong or poorly considered reasons. I believe the vast majority of pilots flying internally regulated machines have little to worry about with respect to self-immolation-by-load-dump. The only thing "special" about our application is the desire to exercise operating panel control over all power sources including alternators. This means there is a switch that either (1) opens the field excitation path or (2) opens a b-lead disconnect contactor. Adding OV protection to EITHER configuration is easy. (2) is a special case where normal operation of a control may produce a load-dump transient. The alternator in question was probably designed to tolerate it. But facts not in evidence go to whether the smoked alternators were in their OEM configuration. The safest thing to do is assume that all such alternators are at-risk and mitigate the risk by prudent design. It's easy and cheap to do. In any case the load dump induced failure is no more perilous to aircraft or pilot than a failure for any other reason (loose b-lead nut, broken belt, etc.). Bob . . . ________________________________________________________________________________
Date: Jan 18, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Aircraft Theft Protection
From time to time we've participated in discussions about aircraft security with respect to theft with many builders gravitating toward key switches, hidden switches, etc. I've often offered the story about bringing a rental airplane home after I'd lost the key by simply breaking the p-leads loose from the mag switch and propping the engine. After I got home, I dug up the spare key, cut a replacement for the lost key and crimped new terminals on the p-leads. I think my overall favorite anti-theft technique involves use of a covered length of hard chain and an equally hard lock looped over the propeller blades. This morning I was walking in from another look at the "Beechjet from Hell" and saw this airplane sitting on the ramp: http://www.aeroelectric.com/Pictures/AC_Theft_Protection.jpg Like most aircraft of the genre, once you're inside the airplane, it belongs to you. But the simple addition to the left propeller is about as forceful a deterrent to flight as I can imagine. Bob . . . -------------------------------------------------------- < Throughout history, poverty is the normal condition > < of man. Advances which permit this norm to be > < exceeded -- here and there, now and then -- are the > < work of an extremely small minority, frequently > < despised, often condemned, and almost always opposed > < by all right-thinking people. Whenever this tiny > < minority is kept from creating, or (as sometimes > < happens) is driven out of a society, the people > < then slip back into abject poverty. > < > < This is known as "bad luck". > < -Lazarus Long- > <------------------------------------------------------> http://www.aeroelectric.com ________________________________________________________________________________
Date: Jan 18, 2005
From: Dj Merrill <deej(at)thayer.dartmouth.edu>
Subject: Re: Fix for radio noise
Robert L. Nuckolls, III wrote: > This is the first time since I've been publishing the 'Connection > that I've become aware of a mag noise problem so intractable as > to require the p-lead filters in addition to ordinary shielding. > > Bob . . . BTW, I used your suggestion of installing the Radio Shack 10A noise filters on my strobe power supplies, and it completely cleaned up the noise I was hearing in my headset. Thanks! :-) -Dj -- Dj Merrill deej(at)thayer.dartmouth.edu "TSA: Totally Screwing Aviation" ________________________________________________________________________________
From: "earl_schroeder(at)juno.com" <earl_schroeder(at)juno.com>
Date: Jan 19, 2005
Subject: GPS wiring?
I have a 'surplus' mouse type GPS receiver purchased from ebay. It works fine with my laptop via the USB port. I would like to use this GPS receiver to provide data to a TruTrak autopilot which needs NEMA 0183 provided by this GPS. I have determined that the outer two USB pins provide power but which of the two center pins is data? And I assume it is referenced to the negative side of the power? If I wanted to use a scope to see the data, what 'load' should be placed on the data line? Maybe someone could point to a URL to obtain this info. I've tried email to the mfg but no response. Thanks, Earl (if this is outside the scope of this list, surely someone will let me know) ________________________________________________________________________________
From: "cgalley" <cgalley(at)qcbc.org>
Subject: Re: Aircraft Theft Protection
Date: Jan 18, 2005
Unless that chain is looped around the left hand blade and you can't tell from the picture, It has NO Protection ----- Original Message ----- From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> Subject: AeroElectric-List: Aircraft Theft Protection > > From time to time we've participated in discussions about aircraft > security with respect to theft with many builders gravitating > toward key switches, hidden switches, etc. > > I've often offered the story about bringing a rental airplane > home after I'd lost the key by simply breaking the p-leads loose > from the mag switch and propping the engine. After I got > home, I dug up the spare key, cut a replacement for the > lost key and crimped new terminals on the p-leads. > > I think my overall favorite anti-theft technique involves > use of a covered length of hard chain and an equally hard > lock looped over the propeller blades. This morning I was > walking in from another look at the "Beechjet from Hell" > and saw this airplane sitting on the ramp: > > http://www.aeroelectric.com/Pictures/AC_Theft_Protection.jpg > > Like most aircraft of the genre, once you're inside the airplane, > it belongs to you. But the simple addition to the left propeller > is about as forceful a deterrent to flight as I can imagine. > > > Bob . . . > > > -------------------------------------------------------- > < Throughout history, poverty is the normal condition > > < of man. Advances which permit this norm to be > > < exceeded -- here and there, now and then -- are the > > < work of an extremely small minority, frequently > > < despised, often condemned, and almost always opposed > > < by all right-thinking people. Whenever this tiny > > < minority is kept from creating, or (as sometimes > > < happens) is driven out of a society, the people > > < then slip back into abject poverty. > > < > > < This is known as "bad luck". > > < -Lazarus Long- > > <------------------------------------------------------> > http://www.aeroelectric.com > > ________________________________________________________________________________
From: "Brian Kraut" <brian.kraut(at)engalt.com>
Subject: GPS wiring?
Date: Jan 18, 2005
I doubt that you are going to have any luck here because NMEA data is standard at 4,800 baud and is in a specific serial format. I am not a USB expert, but I suspect that the USB data coming from the antenna is vastly different than what you need. I am also not familiar with the Trutrack autopilot, but I am very familiar with marine autopilots and 99% of the marine autopilots are looking mainly for crosstrack error from the GPS when you have the GPS programmed to steer to a waypoint. When you are not steering to a waypoint the only usefull data that the pilot uses from the GPS is speed. Since you can not program a waypoint without the computer hooked up your autopilot might not care less even if you do get the data from the GPS into it. By the way, I manufacture a NMEA splitter that provides six independent outputs from a single input. I sell a ton of them in the marine industry because it is common to interface GPSs, speed logs, sounders, etc. to sometimes a dozen or more pieces of equipment that use the data. I am not sure how common a problem it is on aircraft to run out of drive capability on your GPS, but if there is any interest click on MARINE PRODUCTS on my web site. I also make a handheld NMEA simulator and do other custom interface solutions. Brian Kraut Engineering Alternatives, Inc. www.engalt.com -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of earl_schroeder(at)juno.com Subject: AeroElectric-List: GPS wiring? I have a 'surplus' mouse type GPS receiver purchased from ebay. It works fine with my laptop via the USB port. I would like to use this GPS receiver to provide data to a TruTrak autopilot which needs NEMA 0183 provided by this GPS. I have determined that the outer two USB pins provide power but which of the two center pins is data? And I assume it is referenced to the negative side of the power? If I wanted to use a scope to see the data, what 'load' should be placed on the data line? Maybe someone could point to a URL to obtain this info. I've tried email to the mfg but no response. Thanks, Earl (if this is outside the scope of this list, surely someone will let me know) ________________________________________________________________________________
Date: Jan 18, 2005
From: Rob Logan <Rob(at)logan.com>
Subject: Re: Dynon Efis
> on initial takeoff and chandelle type maneuvers (such as a closed > pull-up, or first turn out of traffic), the unit had significant > acceleration errors and frequently showed erroneous bank angles. The $15k certified xbow 500 in my lancair will display a slight tilt too.. very distracting, but far from "significant". Its still way better than any spinning tungsten because the kalman filter level it within a min. (no caging) enough so I trust mine IMC with a backup T&B. the trick is to fly GPS barring and track (or Chelton velocity vector) for the first min. Rob ________________________________________________________________________________
Date: Jan 18, 2005
From: Rob Logan <Rob(at)logan.com>
Subject: Re: WAAS or Not
> At airports located in high obstacle fields, the lowest minima > will almost always be via a non precision level flight segment while this is true, a CNX80 loaded with 2.0 software or any Chelton will provide vertical guidance below MDA from FAF to MAP via a perfect to hit dirt (yea its shallow) GS. with a Chelton one can do a "VFR" approach with any angle GS (all the way to dirt) but I prefer to take the surveyed path up high. For those that have pushed mins, ground lighting is extremely important.. heck, I've gone missed on an ILS twice and then went to an airport with centerline lighting and made it.. Lighting is extremely important. This and another experience makes me note the type of lighting (RAIL) before any approach. The point the original author of the thread was trying to make before it was hijacked was: Does the shutdown of your entire navigator if one very hard to receive SV signal is lost, increase safety? wouldn't some information be better than none? Bob's been waiving the MDA, LPV minima flag for 3+ years to keep us legal, and that's *very* important. but these navigators offer real life advantages, and lets hope that can be improved too. Rob ________________________________________________________________________________
Date: Jan 18, 2005
From: Rob Logan <Rob(at)logan.com>
Subject: Re: GPS wiring?
> I have a 'surplus' mouse type GPS receiver purchased from ebay. there is a block in the middle of the cable that's rs232 to usb. cut that out and you have: red 6-40vdc black ground blue rx white tx green (rx for dgps, leave n/c) from http://www.garmin.com/manuals/GPS35LPSeries_TechnicalSpecification.pdf Rob ________________________________________________________________________________
From: "Werner Schneider" <glastar(at)gmx.net>
Subject: Re: Fix for radio noise
Date: Jan 19, 2005
What kind (brand/type) of noise filters were used here? Thx Werner ----- Original Message ----- From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> Subject: Re: AeroElectric-List: Re: Fix for radio noise > > > > > > > >I thought I would post the results of noise fix. I installed both mag > >filters. (tedious) and fixed the noise. charlie heathco ATL. > > > Thank you Charlie. For other folks on the list, Charlie called a couple > of weeks ago complaining of magneto noise in radio. He had already > wired per Z-figures and was reasonably sure spark plug harnesses > were okay. I suggested magneto p-lead noise filters. He's now reporting > success with the noise problem. > > This is the first time since I've been publishing the 'Connection > that I've become aware of a mag noise problem so intractable as > to require the p-lead filters in addition to ordinary shielding. > > Bob . . . > > ________________________________________________________________________________
Subject: Aircraft Theft Protection
Date: Jan 19, 2005
From: "George Braly" <gwbraly(at)gami.com>
Bob, Oh! Boy! Can't wait to see the first NTSB accident report on this one. Not a question of "if" - - only a question of when. Besides, who would want to steal THAT thing??? And what would you do with it after you sole it? Regards, George -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L. Nuckolls, III Subject: AeroElectric-List: Aircraft Theft Protection From time to time we've participated in discussions about aircraft security with respect to theft with many builders gravitating toward key switches, hidden switches, etc. I've often offered the story about bringing a rental airplane home after I'd lost the key by simply breaking the p-leads loose from the mag switch and propping the engine. After I got home, I dug up the spare key, cut a replacement for the lost key and crimped new terminals on the p-leads. I think my overall favorite anti-theft technique involves use of a covered length of hard chain and an equally hard lock looped over the propeller blades. This morning I was walking in from another look at the "Beechjet from Hell" and saw this airplane sitting on the ramp: http://www.aeroelectric.com/Pictures/AC_Theft_Protection.jpg Like most aircraft of the genre, once you're inside the airplane, it belongs to you. But the simple addition to the left propeller is about as forceful a deterrent to flight as I can imagine. Bob . . . -------------------------------------------------------- < Throughout history, poverty is the normal condition > < of man. Advances which permit this norm to be > < exceeded -- here and there, now and then -- are the > < work of an extremely small minority, frequently > < despised, often condemned, and almost always opposed > < by all right-thinking people. Whenever this tiny > < minority is kept from creating, or (as sometimes > < happens) is driven out of a society, the people > < then slip back into abject poverty. > < > < This is known as "bad luck". > < -Lazarus Long- > <------------------------------------------------------> http://www.aeroelectric.com --- --- ________________________________________________________________________________
From: "Chris Horsten" <airplanes(at)sympatico.ca>
Subject: GPS wiring?
Date: Jan 19, 2005
Earl, Not sure I can offer any help - but I have a question about the mouse type GPS. I take it you mean a simple black blob with no display or buttons? If so, what use will it serve you when connected to your autopilot? If its function is to simply provide position info, how will this make your AP useful except to hold course? I have a 296 which I have interfaced to my TRIO AP. The idea is that you enter a goto on the GPS and then the TRIO picks it up and follows it. Am I missing something here with your setup? Chris -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of earl_schroeder(at)juno.com Subject: AeroElectric-List: GPS wiring? --> I have a 'surplus' mouse type GPS receiver purchased from ebay. It works fine with my laptop via the USB port. I would like to use this GPS receiver to provide data to a TruTrak autopilot which needs NEMA 0183 provided by this GPS. I have determined that the outer two USB pins provide power but which of the two center pins is data? And I assume it is referenced to the negative side of the power? If I wanted to use a scope to see the data, what 'load' should be placed on the data line? Maybe someone could point to a URL to obtain this info. I've tried email to the mfg but no response. Thanks, Earl (if this is outside the scope of this list, surely someone will let me know) advertising on the Matronics Forums. ________________________________________________________________________________
Date: Jan 19, 2005
From: Bikcrzy(at)aol.com
Subject: Re: Fuse-link
Thanks Bob and Ken, Your answers regarding the fuse-link cleared up the mystery. Back to wiring. JR ________________________________________________________________________________
Date: Jan 19, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Aircraft Theft Protection
> >Bob, > >Oh! Boy! Can't wait to see the first NTSB accident report on this one. Wouldn't read much differently than for the pilot who took off with surface locks, pitot covers, or engine cooling inlet covers in place . . . >Not a question of "if" - - only a question of when. > >Besides, who would want to steal THAT thing??? Drug runners >And what would you do with it after you stole it? Run drugs . . . or part it out. There are plenty of countries wherein folks are not particularly concerned with the pedigree of repair parts. Once the airplane is on the ground south of the border, it could easily disappear into dozens if not hundreds of small boxes and crates. Bob . . . ________________________________________________________________________________
Date: Jan 19, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: GPS wiring?
> > >I doubt that you are going to have any luck here because NMEA data is >standard at 4,800 baud and is in a specific serial format. I am not a USB >expert, but I suspect that the USB data coming from the antenna is vastly >different than what you need. > >I am also not familiar with the Trutrack autopilot, but I am very familiar >with marine autopilots and 99% of the marine autopilots are looking mainly >for crosstrack error from the GPS when you have the GPS programmed to steer >to a waypoint. When you are not steering to a waypoint the only usefull >data that the pilot uses from the GPS is speed. How about present course? We've done several GPS implementations for targets at RAC that hold present course or steer to new course before implementing a more precise course + CTE steering. Bob . . . ________________________________________________________________________________
Date: Jan 19, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Aircraft Theft Protection
> >Unless that chain is looped around the left hand blade and you can't tell >from the picture, It has NO Protection It is looped around two blades. Bob . . . ________________________________________________________________________________
Subject: Re: Aircraft Development Expense
Date: Jan 19, 2005
From: "Chuck Jensen" <cjensen(at)dts9000.com>
Eric wrote... But I digress....Here's the plan: Since the economic well-being of ...oh, pick a name out of the air...Raytheon, depends greatly on an efficient FAA certification process, it would behoove Raytheon management to get their state representatives to wake up and smell the av-gas. Or else. I think your on to something--Naivety. Mainly, that Raytheon, Boeing, et al care about the certification process, TSO, et al. They are engineering monsters with a whole organization geared toward paper-piling and pencil-whipping. Look at one of the recent Citations that went through certification--less than two years. And Airbus, with their new flying football field, the shakedown and flight testing is schedule for about 12 months. By comparison, it takes two years to TSO a single component that doesn't do anything in a certified aircraft. The certification process is bureaucratic--granted. The certification process is archaic--true. But, there are a lot of lazy aircraft companies (can you say "Cessna") that used the certification process as an excuse for not upgrading/improving/innovating new products and improvements--also true. Cirrus didn't seem all that hamstrung in the certification process. So yes, we should work at changing the system, but it shouldn't be used as an excuse for not pushing forward. Chuck ________________________________________________________________________________
Date: Jan 19, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Aircraft Development Expense
> >Eric wrote... > >But I digress....Here's the plan: Since the economic well-being of ...oh, >pick a name out of the air...Raytheon, depends greatly on an efficient FAA >certification process, it would behoove Raytheon management to get their >state representatives to wake up and smell the av-gas. Or else. > > >I think your on to something--Naivety. Mainly, that Raytheon, Boeing, et >al care about the certification process, TSO, et al. They are engineering >monsters with a whole organization geared toward paper-piling and >pencil-whipping. Look at one of the recent Citations that went through >certification--less than two years. And Airbus, with their new flying >football field, the shakedown and flight testing is schedule for about 12 >months. > >By comparison, it takes two years to TSO a single component that doesn't >do anything in a certified aircraft. The certification process is >bureaucratic--granted. The certification process is archaic--true. But, >there are a lot of lazy aircraft companies (can you say "Cessna") that >used the certification process as an excuse for not >upgrading/improving/innovating new products and improvements--also >true. Cirrus didn't seem all that hamstrung in the certification >process. So yes, we should work at changing the system, but it shouldn't >be used as an excuse for not pushing forward. This may be an over-simplification. But it's true that industry (not necessarily limited to aircraft) have been trending toward more no-value-added-activities over the years. The shift has come from MANY forces not the least of which are legal departments, demands from the outside to conform to ISO this, EPA that, and OSHA something else. 75 years ago, Walter Beech personally presided over a few dozen engineers and if he wanted to know how the development efforts were going, it was all happening in one hangar right outside. When a new project involves hundreds of engineers, hundreds of suppliers, hundreds of assembly workers, the paper mountain grows exponentially. Yes, everyone worries about not letting things fall through cracks . . . so they write more rules, policies and procedures. There is a sort of faith that once a requirement is codified in black and white that the subject worry about which the document was crafted will magically go away. Problem is that every new rule must be presided over by somebody . . . no-value-added labor (and subsequent delays) is proportional to weight of the rules documents. What we're experiencing is a global shift from individuals with skill, creativity and dedication being able to operate largely "leaderless" with respect to the details of their craft. Now, everyone is expected to know and follow all the procedures, work instructions, policies, etc to the letter. Show this will result in the perfect product being pushed out the door. This is why the "skunk works" style environments like Cirrus and Lancair seem to move forward with such dispatch . . . Walter would be proud of them. Walter knew that real leadership involves setting goals and the flavor of the product and then making it a priority to clear away any obstacles that impede the progress of a skilled staff. I now see individuals at gate reviews reporting on the most minute details of their efforts to folks very high up on the management ladder . . . have no idea if the managers really understand what they're hearing/seeing but the new policies and procedures require that they go through the motions. This is happening both inside offices of the regulators and the regulated . . . it's almost as if there's some like of a contest to see who can preside over the most complete set of rules. Did some work for these folks about a year ago: http://questaircraft.com/specifications.htm This whole project is driven by perhaps 30 folks in one building up in the cold north country. Walter would be proud of these guys too. Bob . . . ________________________________________________________________________________
From: "Glen Matejcek" <aerobubba(at)earthlink.net>
Subject: Aircraft theft protection
Date: Jan 19, 2005
Hi Bob- While I certainly and whole heartedly agree with your comments on theft protection, it seems to me that in the photo you provided that turning the prop 180 degrees by hand would defeat the depicted arrangement.... Glen Matejcek aerobubba(at)earthlink.net ________________________________________________________________________________
Subject: Re: Aircraft Development Expense
Date: Jan 19, 2005
From: "Chuck Jensen" <cjensen(at)dts9000.com>
In the nuclear industry, we've gone through the complete conversion from relying on people to relying on procedures. When something goes wrong, instead of people being held accountable, the blame is directed first to deficient procedures, then failure to adhere to procedures, then inadequate training. Rarely is personal stupidity cited as the casual factor, though it is high on the list of real reasons. I suspect the size and complexity of an organization dictates some of this migration to paper and policies. You can manage 30 engineers, but 300 engineers must be controlled. And the controls of choice are codes, regulations, procedures and policies. In the end, if you want to spend big bucks and make press releases, think BIG. If you need to get something done expeditiously and at a reasonable cost, think SMALL. Chuck Bob wrote.. What we're experiencing is a global shift from individuals with skill, creativity and dedication being able to operate largely "leaderless" with respect to the details of their craft. Now, everyone is expected to know and follow all the procedures, work instructions, policies, etc to the letter. Show this will result in the perfect product being pushed out the door. This is why the "skunk works" style environments like Cirrus and Lancair seem to move forward with such dispatch . . . Walter would be proud of them. Walter knew that real leadership involves setting goals and the flavor of the product and then making it a priority to clear away any obstacles that impede the progress of a skilled staff. I now see individuals at gate reviews reporting on the most minute details of their efforts to folks very high up on the management ladder . . . have no idea if the managers really understand what they're hearing/seeing but the new policies and procedures require that they go through the motions. This is happening both inside offices of the regulators and the regulated . . . it's almost as if there's some like of a contest to see who can preside over the most complete set of rules. Did some work for these folks about a year ago: http://questaircraft.com/specifications.htm This whole project is driven by perhaps 30 folks in one building up in the cold north country. Walter would be proud of these guys too. Bob . . . ________________________________________________________________________________
Date: Jan 19, 2005
From: rv-9a-online <rv-9a-online(at)telus.net>
Subject: Re: P-Mag Wiring
I'm not Bob, but I've ordered my p-mag/e-mag set. I had the factory review my schematic and they provided some useful tips. I'm using a seperate 'P-Lead' ACS ignition switch, and a Dual pole switch for mag power. E-Mag Ignitions recommends having each mag on it's own seperate power feed/breaker. I chose to have two breakers and my dual pole switch. They say that a switchable/pullable break is also acceptable (allows pre-flight testing of p-mag). So whatever you come up with, have E-mag Ignitions check it over, they are very helpful Vern Little RV-9A C-FRVL waiting for engine (and e-mag/p-mags) dsvs(at)comcast.net wrote: > > >Bob, >I am in the process of setting up my electrical system and have a "Switch" question. The P-mag needs a P-lead type switch and a power switch. To save space I would like to use one switch for both operations. A three position switch could be used for this if one with the needed configuration is available. do you know of such a switch? Thanks. Don > > >Bob, >I am in the process of setting up my electrical system and have a "Switch" question. The P-mag needs a P-lead type switch and a power switch. To save space I would like to use one switch for both operations. A three position switch could be used for this if one with the needed configuration is available. do you know of such a switch? Thanks. Don > > > > ________________________________________________________________________________
From: <bakerocb(at)cox.net>
Subject: Encoder test
Date: Jan 19, 2005
> From: "Larry McFarland" <larrymc(at)qconline.com> > Subject: Re: AeroElectric-List: Encoder test > > > > Richard, > The encoder has to be tested by an authorized instrument repairman that > can > tag it > for use in controlled airspace. There are methods available for you to do > it, but I wouldn't > get too excited about that. The system coupled with your altimeter will > be > tested to 20,000 ft > the first time in an installation. Your Airworthiness Cert will require > you > have this done beforehand......skip....... 1/19/2005 Hello Larry, Not true. In fact there may be some advantage in waiting to have your initial inspection done and Airworthiness Cert in hand before you have your FAR Sec. 91.413 transponder check done. If you have your transponder check done before the initial inspection and then don't pass the initial inspection for some reason you could waste a portion of the two years that the transponder check is good for before you start flying. Also if someone is not going to fly in airspace that requires a transponder (See FAR Sec. 91.215 (b) (1) through (5)) then he may not have a transponder installed and that alone would not prevent issuance of the Airworthiness Cert at the time of the initial inspection. OC -- Checked by AVG Anti-Virus. ________________________________________________________________________________
Date: Jan 19, 2005
From: Harley <harley(at)AgelessWings.com>
Subject: Re: Aircraft theft protection
The chain is around TWO blades...it's not big enough to drop off both of them, or come off first one then the other. Harley Glen Matejcek wrote: > >Hi Bob- > >While I certainly and whole heartedly agree with your comments on theft >protection, it seems to me that in the photo you provided that turning the >prop 180 degrees by hand would defeat the depicted arrangement.... > >Glen Matejcek >aerobubba(at)earthlink.net > > > > Checked by AVG Anti-Virus. ________________________________________________________________________________
From: "Bob White" <bob(at)whitek.com>
Subject: Re: Aircraft theft protection
Date: Jan 19, 2005
One certainly wouldn't think that trolling was necessary on this list. Bob White ----- Original Message ----- From: "Glen Matejcek" <aerobubba(at)earthlink.net> Subject: AeroElectric-List: Aircraft theft protection Hi Bob- While I certainly and whole heartedly agree with your comments on theft protection, it seems to me that in the photo you provided that turning the prop 180 degrees by hand would defeat the depicted arrangement.... Glen Matejcek aerobubba(at)earthlink.net ________________________________________________________________________________
From: <bakerocb(at)cox.net>
Subject: Lycoming starter on ebay
Date: Jan 19, 2005
Avionics-List message previously posted by: Hopperdhh(at)aol.com > I was browsing ebay and came across this starter for airboats. Why > airboats? Is it because of liability? It looks like the price is pretty > good > for a new starter.....skip....... Dan Hopper 1/19/2005 Hello Dan, FAR Sec. 21.303 says "....no person may produce a modification or replacement part for sale for installation on a type certificated product unless it is produced pursuant to a Parts Manufacturer Approval issued under this subpart." I would suspect that the person producing these starters does not have PMA for them so in order to avoid violating FAR Sec. 21.303 he says they are strictly for airboats. The regulations preventing people from installing these starters on type certificated aircraft are a little more indistinct or unknown and a person could install one on a type certificated aircraft either out of ignorance of the regulations or outright flouting of the regulations.** There is no regulation that would prevent a person from using such a starter on an amateur built experimental aircraft. OC **PS: What FAR prevents the installation of non approved parts in type certificated aircraft? The closest that I can come to such a prohibition is FAR Sec 43.13 (b) which says "Each person maintaining or altering, or performing preventive maintenance, shall do that work in such a manner and use materials of such a quality, that the condition of the aircraft, airframe, aircraft engine, propeller, or appliance worked on will be at least equal to its original or properly altered condition with regard to aerodynamic function, structural strength, resistance to vibration and deterioration, and other qualities affecting airworthiness." -- Checked by AVG Anti-Virus. ________________________________________________________________________________
From: <bakerocb(at)cox.net>
Subject: Lighting Source
Date: Jan 19, 2005
1/19/2005 Hello Fellow Builders, This lighting source may be well known to many of you, but I just learned of it and thought I'd share the info. https://ssl.perfora.net/gs-air.com/sess/utn;jsessionid=1541ee915db8cd2/shopdata/index.shopscript Eric M. Jones, I'd be interested in your comments on their LED based light offerings. OC -- Checked by AVG Anti-Virus. ________________________________________________________________________________
From: "Bob White" <bob(at)whitek.com>
Subject: Re: Encoder test
Date: Jan 19, 2005
What is this authorized instrument repairman that you speak of? I'm familiar with IA and A&P, but I've always wondered if avionics required a licensed repairman. Bob White ----- Original Message ----- From: <bakerocb(at)cox.net> Subject: AeroElectric-List: Encoder test > From: "Larry McFarland" <larrymc(at)qconline.com> > Subject: Re: AeroElectric-List: Encoder test > > > > Richard, > The encoder has to be tested by an authorized instrument repairman that > can > tag it > for use in controlled airspace. There are methods available for you to do > it, but I wouldn't > get too excited about that. The system coupled with your altimeter will > be > tested to 20,000 ft > the first time in an installation. Your Airworthiness Cert will require > you > have this done beforehand......skip....... 1/19/2005 Hello Larry, Not true. In fact there may be some advantage in waiting to have your initial inspection done and Airworthiness Cert in hand before you have your FAR Sec. 91.413 transponder check done. If you have your transponder check done before the initial inspection and then don't pass the initial inspection for some reason you could waste a portion of the two years that the transponder check is good for before you start flying. Also if someone is not going to fly in airspace that requires a transponder (See FAR Sec. 91.215 (b) (1) through (5)) then he may not have a transponder installed and that alone would not prevent issuance of the Airworthiness Cert at the time of the initial inspection. OC -- Checked by AVG Anti-Virus. ________________________________________________________________________________
Date: Jan 19, 2005
From: Mickey Coggins <mick-matronics(at)rv8.ch>
Subject: Re: Fix for radio noise
Hi Dj, Are these filters between the power supply and the 12v input or the ground? Where did you have them grounded when you had the noise? Thanks, Mickey > BTW, I used your suggestion of installing > the Radio Shack 10A noise filters on my strobe > power supplies, and it completely cleaned up the > noise I was hearing in my headset. > > Thanks! :-) > > -Dj > -- Mickey Coggins http://www.rv8.ch/ #82007 Wiring ________________________________________________________________________________
Date: Jan 19, 2005
From: Mickey Coggins <mick-matronics(at)rv8.ch>
Subject: Re: GPS wiring?
Hi Chris, How did you wire it up? Did you get a PC cable from Garmin and chop it up? Thanks, Mickey > I have a 296 which I have interfaced to my TRIO AP. The idea is that you > enter a goto on the GPS and then the TRIO picks it up and follows it. Am I > missing something here with your setup? > -- Mickey Coggins http://www.rv8.ch/ #82007 Wiring ________________________________________________________________________________
From: "Larry McFarland" <larrymc(at)qconline.com>
Subject: Re: Encoder test
Date: Jan 19, 2005
You're absolutely right. I posted from the myopic view of my own experience where I couldn't fly from my airport without the transponder. The inspector was aware of the circumstances and said that he expected these things to be in order before issuance of the Certification. I made the assumption that everyone flies in and out of the controlled fields that carries a transponder. Obviously not true. I'm based where jets are in regular schedule at a C-controlled field and it's sometimes busy enough to justify it. Thanks for pointing that out. The more important point of the installation is, keep the thing accessible for troubleshooting and the next inspection because you cannot predict when you're going to have to get to it again. Larry McFarland Your Airworthiness Cert will require you have this done beforehand......skip....... > > 1/19/2005 > > Hello Larry, Not true. In fact there may be some advantage in waiting to > have your initial inspection done and Airworthiness Cert in hand before > you > have your FAR Sec. 91.413 transponder check done. > > If you have your transponder check done before the initial inspection and > then don't pass the initial inspection for some reason you could waste a > portion of the two years that the transponder check is good for before you > start flying. > > Also if someone is not going to fly in airspace that requires a > transponder > (See FAR Sec. 91.215 (b) (1) through (5)) then he may not have a > transponder > installed and that alone would not prevent issuance of the Airworthiness > Cert at the time of the initial inspection. > > OC > > > -- > Checked by AVG Anti-Virus. ________________________________________________________________________________
From: "Steve Sampson" <steve(at)lbho.freeserve.co.uk>
Subject: RE: [rvsqn] 1/4 wave groundplane
Date: Jan 19, 2005
Oops! That was meant to go to aeroelectric > -----Original Message----- > From: Steve Sampson [mailto:Steve(at)lbho.freeserve.co.uk] > Sent: 19 January 2005 18:09 > To: RV Squadron (E-mail) > Subject: [rvsqn] 1/4 wave groundplane > > Bob - I would welcome your comments. > > In the bumph the PFA (roughly the British EAA) gives out there is some > stuff about aerials. It includes...... > > "Even some professional radio installers seem to think that if the braid > of the feeder coax is firmly connected to the metal fuselageat the base of > the aerial, then it will do the job. Wrong! At any given frequency the > length of the driven element ...is calculated to be resonant as a 1/4 > wavelength................................But the 'counterpoise' or other > half must also be of similar dimensions so as to present the trans/rec > witha 1/2 wavelength total. The entire fuselage however presents no such > thing and completely unbalances the system................causing a > variety of problems, not least interference and much degraded > performance........ At the base of the aerial the braid should also be > connected to a tuned groundplane either in the form of a down going > insulated wire or number of wires measuring 5% less in length than the > driven element..........................It doe not matter that the > airframe is also connected at its centre..................the oscilating > pulses in the aerial will choose the resonant path both > ways........................................." > > What is your reaction to this? I have never seen this reccomendation > before. He seems to be trying to turn a 1/4 wave into a dipole with half > the aerial inside and half outside. Surely this would cause energy to > bounce around inside a metal aircraft? > > > Thanks, Steve. > RV9a > > -- > Checked by AVG Anti-Virus. > > -- Checked by AVG Anti-Virus. ________________________________________________________________________________
From: "Paul Messinger" <paulm(at)olypen.com>
Subject: Re: Load dump
Date: Jan 19, 2005
Load Dump is Identical when an internally regulated alternator is modified and used with an external regulator. IE the same alternator produces an Identical Load dump when the internal regulator is deleted and an external regulator is used. The type and location of the regulator is not part of the Load dump conditions. I have demonstrated this in my testing. There seems to be some confusion over regulator control/failure etc vs load dump. That some regulators seem to fail in an unclamped load dump and the only reported brand is the Vans rebuilt units is interesting, but so far I have not seen any evidence that the Vans alternator is defective. Perhaps Vans is getting a bad rap, Sadly no one seems interested in finding out what is really the cause of these "reported" failures. Load dump is independent of where the regulator is, and as far as I can determine, what type of regulator. Load Dump is simply what happens when any inductor or inductive device is suddenly hit with a step function reduction if its operating current. When you remove power from a relay in your system that relay coil has a load dump. The "flywheel" diode provides a current path to allow the current to slowly stop using the internal resistance of the coil. With an alternator, the opening of the "B" lead during current production results in a self contained event where the internal parts of the alternator must absorb the load dump event. If there is an internally placed regulator it is the first line of defense and the regulator contains a load dump device that clamps the internal alternator "B" lead voltage to under 40 volts. If the alternator does not have an internal regulator the Load dump event internal voltage increases until the rectifier diodes internal to the alternator break down and clamp the voltage. In this case the internal voltage can be as high as 200 volts. However these diodes are normally not damaged. Load dump is simple and its simply the sudden shedding of a load like turning lights off or simply turning your Com off. The magatitude of the current being removed and the condition of the rest of the electrical system bus determine what happens. With a battery connected, not a ripple is likely. However disconnect the battery when its under heavy charge (charging at say 40 amps) and its likely that a huge voltags spike will occur. There is a large amount of energy (at least by my standards) that needs to be clamped. If a 20 amp average current pulse for 1/5 of a second is small to you, ignore the load dump. But note the current pulse can easilly produce momentary bus voltages in excedes of 40V. If you think everything that might be connected during this event is protected, DREAM ON. Paul ----- Original Message ----- From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> Subject: Re: AeroElectric-List: Load dump and PM alternators > > > ><Gilles.Thesee@ac-grenoble.fr> > > > >Hi Eric and all, > > > >Please pardon me for having followed the load dump thread with a casual eye. > > > > > Load dump is an issue with any source of power that uses a rotating > > > conductor in a magnetic field. By the way, overvoltage and load dump are > > > related in that they both have associated overvoltages. Load dump is a > > > strictly transient OV condition caused by disconnecting a load, but an > > > overvoltage condition can be caused by a failed regulator or other causes > > > and may be long term. Both need to be addressed. > > > > > > >Question : is the load dump issue the same for permanent magnet alternators > >? At first glance I would say there are differences, but would one of you > >experts tell me if I have to reconsider my "ordinary" crowbar OV module > >setup ? > > No, only the internally regulated alternators with Figure Z-24 > wiring. There are no special concerns for alternators with external > regulators or permanent magnet alternators. > > Bob . . . > > ________________________________________________________________________________
Date: Jan 20, 2005
From: Frank & Dorothy <frankv(at)infogen.net.nz>
Subject: Microlight battery sizing
clamav-milter version 0.80j on dbmail-mx4.orcon.co.nz Hi I have recently bought a microlight project which includes a Kawasaki 440 (26 cu in) engine with alternator and electric start. I'm trying to figure out what size battery I should buy... The documentation I've found on the engine says that I need a battery capable of delivering 18A or so cranking current. I guess that's reasonable, since BobN uses a figure of 250A for (I guess) something like an O320, which is 10 times as big. BobN recommends a RG type as providing better cranking current than a standard flooded cell battery. There's really no essential electrical load... the only electrical equipment is a handheld radio, perhaps a GPS, perhaps an MP3 player... all of them can run off batteries. I've found a cheap CGB brand (made in China, 12V 7Ah) RG battery for sale. A Net search showed up 25 milli-ohms internal resistance for this battery. Is this going to be suitable? Frank ________________________________________________________________________________
From: "Chris Horsten" <airplanes(at)sympatico.ca>
Subject: GPS wiring?
Date: Jan 19, 2005
Mickey, Actually my cables were made up for me by Stein Air. I provided them with a connector which I bought from Garmin. The other end had bare wires for just such a purpose. Stein used one or two wires from the Garmin and left one or two for power. The rest aren't used. It's the only way to tap into the Garmin unless you hack it up. Mine is still under warranty so not gonna happen. The cable with the bare ends was bout $25 I think. Chris -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Mickey Coggins Subject: Re: AeroElectric-List: GPS wiring? --> Hi Chris, How did you wire it up? Did you get a PC cable from Garmin and chop it up? Thanks, Mickey > I have a 296 which I have interfaced to my TRIO AP. The idea is that > you enter a goto on the GPS and then the TRIO picks it up and follows > it. Am I missing something here with your setup? > -- Mickey Coggins http://www.rv8.ch/ #82007 Wiring ________________________________________________________________________________
From: "Paul Messinger" <paulm(at)olypen.com>
Subject: Re: LOAD dump comments
Date: Jan 19, 2005
First the circuit breakers (several brands) all took more than a few MS to open. The first application of overcurrent with a cold sitting overnight CB took from 70-100 MS to open and when warmed up took around 50 ms to open. To me a few is always less than 10. Thus its likely that the fault time to open will be at least 50 ms and more likely 70+ ms for an unplanned overcurrent. Second batteries have come a long way in the last few years. Short circuit current ability has more than tripled from the flooded cell of the 60's to today's AGM type. The avionics present in the cockpit nay contain devices that measure the earth's magnetic field that are far less able to withstand being around the magnetic field of an arc welder (actually many times what the typical welding current) and that's what we produce with a unlimited current short that the crow bar produces. Its true that any CB can be presented with a dead short load and MAY produce the same current as the Crowbar. The crow bar is Designed to produce huge currents far in excess of what is needed to perform the function and even more than is needed to minimize the trip time. I think its time to leap forward and look at the entire system again in light of modern avionics and batteries etc and consider a new approach to the design of overvoltage protection current production etc. I wonder how many avionics manufacturers would approve of your asking for permission to do welding in the cockpit near the their equipment with an arc welder. The addition of a simple resistor in the crow bar design would completely eliminate the huge currents and have zero effect on the trip time or functional usage of the OVP. The use of solid state switches VS fuses and or CB provide simple ways to protect and NOT produce huge fault currents. I have seen far too often what happens when a system design is slowly updated over the years and there is never a updated total design review to see what the result of a new mod will do the "old" design. Just consider replacing the battery with one that increases the short current max from 300 amps to 2000 amps. Then when the Fuse or CB pops you are getting a pre pop current of 2000 amps vs. what was originally considered OK of 300 amps. (Exaggerated for effect) Now lets remove the whiskey compass and install integrated magnetometers designed for extremely low magnetic fields. Even exposing that device to a 300 amp current generated field needs review not considering what a 2000 amp field could do. What upsets me is the concept of deliberately producing a huge short current to open a relay. Why just design a OVP that opens a circuit ,not shorts it, and then depends on another device to open so a third device opens finally doing the intended job. We have the OVP a CB and finally a contactor. Why not have the OVP do it all or at least directly open the contactor. I know its over simplification here but one solid state modern device can do all the functions of the contactor and OVP as well as the CB in the sense of being able to disconnect the "B" lead. Think about it. We are rehashing the electrical system and piecemeal upgrading a system designed 50 years ago and avionics had tubes. We have modern avionics we need modern electrical systems to match. I am following up with a more specific email on modern electrical design. Paul > It still amuses me that some folks are happy to have > circuit breakers interrupt current to a faulted > wire but get their shorts in a bunch when we > deliberately fault a wire downstream of a breaker > to corral a runaway alternator. The SAME fault currents > flow in both instances. Yes, it's certainly hundreds > of amps. But irrespective of WHY the breaker or fuse > opens, the event terminates in milliseconds, effects > on the rest of the system are the same and of no > particular significance. ________________________________________________________________________________
From: "Larry McFarland" <larrymc(at)qconline.com>
Subject: Re: Encoder test
Date: Jan 19, 2005
Bob, There are levels of authorization for repair of Avionics and instruments that provide a level of assurance for IFR flight, qualify insurance and these are coupled with the equipment that go along with FAA approved facilities. The transponder is one which you can test, but if you fly into controlled airspace, you'd best be carrying the tags on your altimeter and transponder to show you have the legal equipment & authorization to fly there. We have a facility on our field that does such work on jets to private aircraft and I'm glad they're there. They are Quad City Aviation & Instruments, 309-507-1280, Mgr Tim McKune Web site, Quad_City_Aviation(at)hotmail.com. Tim worked quite a while setting up the facility and is repairing radios, instruments, testing transponders and has the authorization to overhaul or repair any instrument or transceiver, etc. Very good people that work well with the little guy like myself. Larry McFarland - 601hds - Stratus - 50 hrs. www.macsmachine.com Subject: Re: AeroElectric-List: Encoder test > > What is this authorized instrument repairman that you speak of? I'm > familiar with IA and A&P, but I've always wondered if avionics required a > licensed repairman. > > Bob White ________________________________________________________________________________
From: "Ron Raby" <ronr(at)advanceddesign.com>
Subject: Re: Load Dump
Date: Jan 19, 2005
Bob, Thanks for the response. The system is wired to a double pole double throw switch. one side switches the return to the battery contactor. the other is wired from the main buss to a 5 amp pullable circuit breaker, then to the other pole of the switch, and on to terminal 6 on the LR3C -14 voltage regulator. I do have the crossfeed on light, it is built into the switch. Should I ajust the voltage's on both systems to be the same? The voltage readouts are picked up after the battery contactors. EDM 900 and on the Dynon. If I hit the crossfeed I am then reading the voltages from the one system. Would it make sense to get these readouts from the battery buss? That way If you shut a system off you would still have an indication to what was going on with the battery you shut off. Regards Ron Raby ----- Original Message ----- From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> Subject: Re: AeroElectric-List: Load Dump > > > >> >> >>Bob >> >>I have some procedure questions. >> >>I have my plane wired per Z14. In the event of a low volt warning. Do I >>just >>turn on the crossfeed contactor? or do I pull the circuit breaker going to >>the B&C regulator and then turn on the crossfeed contactor. > > If your master switches are 2-10 then simply turn off the alternator > on the 'dead' side and close the crossfeed contactor. If the main > alternator fails, then your COMBINED bus loads must be reduced to > 20A or less. Optionally, you could simply shut down the 'dead' side > and treat the working side as an endurance mode operation thus saving > all battery energies for approach to landing. > > >>Is there any problem if the crossfeed contactor is accidentally turned on >>with both system working properly? > > It doesn't hurt anything. If the SD-20 voltage is set higher than > the main alternator, it might cause the loadmeter on the SD-20 to > peg but this isn't a big deal if you catch it in a few minutes. > I presume you have a CROSSFEED ON indicator light? > > Bob . . . > > > ________________________________________________________________________________
Date: Jan 19, 2005
Subject: Rotary Switch
From: Bonnie & August Lehmann <blehmann(at)pris.bc.ca>
Searching for a 5-position, six wire contacts on the back, rotary switch with capacity of 25A (1.5HP) 120V A.C. Background: Mist, blowing snow etc. resulted to my battery booster/engine starter (6V, 12V & 24V) being run over by a ground vehicle. Brand name of the booster/engine starter is SOLAR, model 1670. Upon disassembly I was surprised that the only damage was the volt selector switch. It is manufactured by ARK-LES. Part numbers on the broken switch are 96-07 with 271-91-116A beneath it. I have tracked down the manufacturer of the switch on the net, who referred me to their regional wholesaler who has not replied to any inquiries. One west coast source could provide me with one if I ordered a minimum of 1000 of them. Local retailers who sell the whole unit are eager to sell me another whole unit, but deny having access to any parts for it's repair. As we are constantly bombarded by various conservation concerns to reduce, repair & re-use, it is ironic for me to look at spending up to $600 to replace the whole unit instead of just replacing the switch. Any leads to a sealed rotary, 5 positon, switch with six contact leads at the back, with 25A 120VAC capacity, would help me survive the cold season right now. And I'd be twice as glad if its not an ARK-LES, as I find it objectionable to support a business that appears to be totally unconcerned about backing up people who buy their products. Thank you, List providers for allowing me to post my cry for help. August Lehmann Cyclone 180 builder ________________________________________________________________________________
From: "Werner Schneider" <glastar(at)gmx.net>
Subject: Re: GPS wiring?
Date: Jan 19, 2005
Mickey, there is a cable available which says power data cable (eg. for the 196 it is 010-10082-00 see http://shop.garmin.com/accessory.jsp?sku=010%2D10082%2D00 ) I did use this one for my trutrak and my 196, just did hook it up directly to the ships power system. similar things are available for the 296. And believe it or not, even here in Switzerland =(;o) Take care Werner ----- Original Message ----- From: "Chris Horsten" <airplanes(at)sympatico.ca> Subject: RE: AeroElectric-List: GPS wiring? > > Mickey, > > Actually my cables were made up for me by Stein Air. I provided them with a > connector which I bought from Garmin. The other end had bare wires for just > such a purpose. Stein used one or two wires from the Garmin and left one or > two for power. The rest aren't used. It's the only way to tap into the > Garmin unless you hack it up. Mine is still under warranty so not gonna > happen. The cable with the bare ends was bout $25 I think. > > Chris > > > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Mickey > Coggins > To: aeroelectric-list(at)matronics.com > Subject: Re: AeroElectric-List: GPS wiring? > > --> > > Hi Chris, > > How did you wire it up? Did you get a PC cable from Garmin and chop it up? > > Thanks, > Mickey > > > I have a 296 which I have interfaced to my TRIO AP. The idea is that > > you enter a goto on the GPS and then the TRIO picks it up and follows > > it. Am I missing something here with your setup? > > > > -- > Mickey Coggins > http://www.rv8.ch/ > #82007 Wiring > > ________________________________________________________________________________
From: "Leo J. Corbalis" <leocorbalis(at)sbcglobal.net>
Subject: Re: Rotary Switch
Date: Jan 19, 2005
If you only use one voltage setting you should be able to replace it with a heavy duty SPST switch. Another choice could be an ordinary rotary switch operating several starter solonoid type relays to handle the heavy lifting. Leo Corbalis ----- Original Message ----- From: "Bonnie & August Lehmann" <blehmann(at)pris.bc.ca> Subject: AeroElectric-List: Rotary Switch > > Searching for a 5-position, six wire contacts on the back, rotary switch > with capacity of 25A (1.5HP) 120V A.C. > > Background: > Mist, blowing snow etc. resulted to my battery booster/engine starter (6V, > 12V & 24V) being run over by a ground vehicle. Brand name of the > booster/engine starter is SOLAR, model 1670. Upon disassembly I was > surprised that the only damage was the volt selector switch. It is > manufactured by ARK-LES. Part numbers on the broken switch are 96-07 with > 271-91-116A beneath it. > > I have tracked down the manufacturer of the switch on the net, who referred > me to their regional wholesaler who has not replied to any inquiries. One > west coast source could provide me with one if I ordered a minimum of 1000 > of them. Local retailers who sell the whole unit are eager to sell me > another whole unit, but deny having access to any parts for it's repair. > > As we are constantly bombarded by various conservation concerns to reduce, > repair & re-use, it is ironic for me to look at spending up to $600 to > replace the whole unit instead of just replacing the switch. > > Any leads to a sealed rotary, 5 positon, switch with six contact leads at > the back, with 25A 120VAC capacity, would help me survive the cold season > right now. And I'd be twice as glad if its not an ARK-LES, as I find it > objectionable to support a business that appears to be totally unconcerned > about backing up people who buy their products. > > Thank you, List providers for allowing me to post my cry for help. > > August Lehmann > Cyclone 180 builder > > ________________________________________________________________________________
From: "James Redmon" <james(at)berkut13.com>
Subject: Re: GPS wiring?
Date: Jan 19, 2005
For those of you interested in making a wiring harness for your Garmin GPS, you can get the special plug at the following URL and make you own for a fraction of the cost! http://pfranc.com/projects/g45contr/g45_idx.htm Enjoy, James Redmon Berkut #013 N97TX http://www.berkut13.com > there is a cable available which says power data cable (eg. for the 196 it > is 010-10082-00 see > http://shop.garmin.com/accessory.jsp?sku=010%2D10082%2D00 ) I did use this > one for my trutrak and my 196, just did hook it up directly to the ships > power system. similar things are available for the 296. >> Actually my cables were made up for me by Stein Air. I provided them with > a >> connector which I bought from Garmin. The other end had bare wires for > just >> such a purpose. Stein used one or two wires from the Garmin and left one > or >> two for power. The rest aren't used. It's the only way to tap into the >> Garmin unless you hack it up. Mine is still under warranty so not gonna >> happen. The cable with the bare ends was bout $25 I think. ________________________________________________________________________________
From: "Eric M. Jones" <emjones(at)charter.net>
Subject: Re: Rotary Switch
Date: Jan 19, 2005
>>Searching for a 5-position, six wire contacts on the back, rotary switch with capacity of 25A (1.5HP) 120V A.C. Try these guys--- http://www.surplussales.com/Switches/ Regards, Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge MA 01550-2705 Phone (508) 764-2072 Email: emjones(at)charter.net ________________________________________________________________________________
From: Speedy11(at)aol.com
Date: Jan 19, 2005
Subject: Re: WAAS or Not
John, Your thoughts were not off-the-wall. On the contrary, they were dead on accurate. Stan Sutterfield Tampa www.rv-8a.net In a message dated 1/18/2005 2:59:25 AM Eastern Standard Time, aeroelectric-list-digest(at)matronics.com writes: I doubt if comparing the cost of installing and maintaining the ILS systems vs. the costs to the FAA of implementing WAAS can be done easily. Nor can we blame the loss of signal when not looking at the southern skies on the FAA, as Rob suggests. As Brian notes, the FAA bears little, if any of the cost of the basic GPS system. The architecture is designed for truly world-wide operations by the DOD - not for 95% reliability of navigation by us good GA users. I also believe that the Coast Guard is OPR for the Loran system. Like so many other items benefitting the citizenry, the DOD picks up the huge tab for this wonderful system - not only for U.S. citizens but for the entire world!! Terrorists, drug runners, thugs included. This phenom (almost complete loss of control of a strategic system by its owner) is probably one of the great case studies of public policy, along with the fairly large chunks of money Congress adds to the DOD budget for breast and prostate cancer research every year. And there are many more tucked away in the thousands of line items in that budget. Don't get me wrong. GPS and its progeny, such as moving maps, is perhaps the single most important technological contribution to general aviation in the last 50 years. Now all we need to do is lobby the Hill; get Congress to add a chunk of money to the DOD bill every year for about a decade and have it earmarked for building a 95% reliable WAAS system for us. :-)) Just some off-the-wall thoughts. ________________________________________________________________________________
Date: Jan 19, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: 1/4 wave groundplane?
> > >Oops! That was meant to go to aeroelectric > > > -----Original Message----- > > From: Steve Sampson [mailto:Steve(at)lbho.freeserve.co.uk] > > Sent: 19 January 2005 18:09 > > To: RV Squadron (E-mail) > > Subject: [rvsqn] 1/4 wave groundplane > > > > Bob - I would welcome your comments. > > > > In the bumph the PFA (roughly the British EAA) gives out there is some > > stuff about aerials. It includes...... > > > > "Even some professional radio installers seem to think that if the braid > > of the feeder coax is firmly connected to the metal fuselageat the base of > > the aerial, then it will do the job. Wrong! At any given frequency the > > length of the driven element ...is calculated to be resonant as a 1/4 > > wavelength................................But the 'counterpoise' or other > > half must also be of similar dimensions so as to present the trans/rec > > witha 1/2 wavelength total. The entire fuselage however presents no such > > thing and completely unbalances the system................causing a > > variety of problems, not least interference and much degraded > > performance........ At the base of the aerial the braid should also be > > connected to a tuned groundplane either in the form of a down going > > insulated wire or number of wires measuring 5% less in length than the > > driven element..........................It doe not matter that the > > airframe is also connected at its centre..................the oscilating > > pulses in the aerial will choose the resonant path both > > ways........................................." > > > > What is your reaction to this? I have never seen this reccomendation > > before. He seems to be trying to turn a 1/4 wave into a dipole with half > > the aerial inside and half outside. Surely this would cause energy to > > bounce around inside a metal aircraft? The writer is not "wrong" but he's making a mountain out of a molehill. An airplane is not a perfect world for antennas. Further, his concerns for "degraded performance" generally don't surface as significant realities. VHF Comm antennas have been installed on aircraft for over 60 years. Installations range from nearly ideal (antenna sits on large area of metal "radiating" several wavelengths in all directions. 747s and their like make really good airborne antenna farms. As the airplane gets smaller, the real estate for ground plane goes down. As the airplane becomes fabric over tube, opportunities for using existing features on the airplane as a ground plane or "counterpoise" degrades further and ultimately becomes non-existent on the glass-n- plastic machines. Yes, if you went to the antenna range and quantified performance of the various compromise antennas that have flown on ultra-lights through 747s, one could cheer the data plots on the 747 installation and cry in lots of beer over the results of tests for the ultra-light. Let us consider the most compromised antenna of all - the "rubber duckie" common to bizillions of hand held radios ranging from CB frequencies (27 Mhz) to near microwave (wi-fi products at 5 Ghz). NONE of these products are favored with anything like the ideal antenna when it comes to ground planes. Your hand-held vhf comm transceiver not only has a foreshortened antenna (it should be 23.6 inches long), it has only your very small body capacity to couple thorough to approach anything like a useful ground plane. Bottom line for USEFULNESS of ANY antenna installation is whether or not it serves the intended purpose while avoiding interference with other systems (some folks can use the outside-antenna comm transceiver with no problems while hand-held comm with rubber-duck in cockpit drives some panel mounted stuff zonkers). I've often remarked here on the list about the disparity of comments on Bob Archer's wing tip comm antennas (VERY compromised). One user says, "piece of crap" while another says, "greatest thing since sliced bread". Turns out that one guy never needs to talk to stations more than 10 miles away and the other guy was gunching about not hitting an RCO 40 miles away while he was flying 2000 feet above the terrain. We KNOW that a hand-held performs MUCH better plumbed into the ship's external antenna (no matter how compromised) than it does using just a rubber-duck from the cockpit. However, I'm not going to pitch the rubber-ducks on my hand-helds in favor of an "ideal" antenna with an optimal ground plane. This umbrella sized device would be difficult to open and use in the cockpit. All this stuff applies only to resonant, un-amplified antennas that drive low impedance feedlines (50 ohm coax). There's a whole other world of antennas like amplified GPS antennas, loran antennas, ADF antennas, AM antenna on your car, etc. which are e-field receptors and have their own special worlds that do not (indeed some cannot) depend on any kind of resonant counterpoise or ground plane. The writer was perfectly founded in the physics of the ideal antenna structure but appears unaware of the practical realities of antenna compromise that have performed to the degree EXPECTED and ACCEPTED on airplanes of all sizes for for decades. He may be familiar with the efforts that antenna designers expend to get the most from a broadcast or ground based communications antenna where the GOAL is ANTENNA performance. Our goal is to optimize FLIGHT SYSTEM performance wherein most situations will tolerate "degraded" antenna performance. Please feel free to forward this note to the original author and invite him to join us here on the List. Bob . . . ________________________________________________________________________________
Date: Jan 19, 2005
From: BobsV35B(at)aol.com
Subject: Re: WAAS or Not
Rob Logan Wrote: "while this is true, a CNX80 loaded with 2.0 software or any Chelton will provide vertical guidance below MDA from FAF to MAP via a perfect to hit dirt (yea its shallow) GS. with a Chelton one can do a "VFR" approach with any angle GS (all the way to dirt)" Good Evening Rob, I am having something of a hard time following what you are saying. Is it your contention that following a glide path beyond the published DA without meeting regulatory vision requirements is a safe thing to do? If that is your point, I strongly disagree. While I do think that many of our approaches are poorly drawn (due to policy, not due to the efforts of the folks who have to follow that policy) and that a change in the policy of implementation would be likely to yield much lower minimums at many of those airports located in high obstacle areas, I absolutely do not ever want to encourage anyone to bust minima. If the FEDs use the accuracy available with WAAS to it's optimum advantage, we would gain the greatest good. That is all I am suggesting Following a WAAS generated, or any other glide path, all the away to the dirt when the route to that dirt has not been found clear of obstacles borders on suicide. Happy Skies, Old Bob ________________________________________________________________________________
From: Dww0708(at)aol.com
Date: Jan 20, 2005
Subject: Re: Aircraft Theft Protection
During" oneday on the flight line "an old man started his 182 with one of those chain gangs on the prop, snapped three of the four engine mounts before he realized what he had done. I mean you could see the cross grain of the castings where they exceeded their yield strength, probably makes you go sentimental. That BE 1900 looks like it is covered in Gill Liner internally. Did yall do that cargo mod. I did a few cargo mods on some DO228 s. Love hearing stuff from the Big Shops. David ________________________________________________________________________________
From: "Rob Logan" <rob(at)logan.com>
Subject: Re: Odyssey Battery
Date: Jan 20, 2005
> There is nothing "wrong" with the Odyssey battery . . . > the notion that BATTERY MAINTENANCE should include either ... > replacement of the battery IN SPITE of the fact that it still cranks Odyssey PC680 battery is listed as > 30% state of charge still provides sufficient starting amps > 50% state of charge after 2 years if stored at room temperature > eight year design life or > 400 [cycles] when fully discharged or > 500 [cycles] when discharged to 80% so at 150 cycles a year, that replace every third annual. but http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=4519882933 claims its 7.27'' x 3.11'' x 6.67'' in http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=4520579883 claims its 7.0" in length, 3.0" wide, and 6 9/16" tall. not sure what http://www.bandc.biz/BC116-1.pdf is but its claims 7.1" 6.6" 3.0" did the first guy just get his size wrong or am I missing something or how big is the non MJ PC680? ________________________________________________________________________________
Subject: Re: GPS wiring?
Date: Jan 20, 2005
From: "Lockamy, Jack L" <jack.lockamy(at)navy.mil>
Mickey, Go to www.ebay.com. Do a search for Garmin 010-10082-00. This should get you a large list of available cables at much better prices than you will get from buying direct from Garmin. I think I paid $10 for the cable I'm using on my Garmin 196 connected to a TRIO Avionics Autopilot. Jack Lockamy Camarillo, CA -7A FWF (almost done...) ________________________________________________________________________________
Date: Jan 20, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Aircraft Theft Protection
> >During" oneday on the flight line "an old man started his 182 with one of >those chain gangs on the prop, snapped three of the four engine mounts >before >he realized what he had done. I mean you could see the cross grain of the >castings where they exceeded their yield strength, probably makes you go >sentimental. That BE 1900 looks like it is covered in Gill Liner >internally. Did >yall do that cargo mod. I did a few cargo mods on some DO228 s. Love >hearing stuff from the Big Shops. David At least he didn't get off the ground before he became aware of a critical check-list item. Wonder if he looked into his fuel tanks too . . . Don't know anything about this particular airplane. It was sitting inside the avionics hangar at RAS Wichita two weeks ago during the ice storm and was outside on the ramp Monday when I took the picture. Bob . . . ________________________________________________________________________________
From: "Terry Watson" <terry(at)tcwatson.com>
Subject: Re: Odyssey Battery
Date: Jan 20, 2005
Rob, Here's a page that has a PDF reference for the specs on Odyssey batteries: http://www.batterymart.com/c-odyssey.html Terry did the first guy just get his size wrong or am I missing something or how big is the non MJ PC680? ________________________________________________________________________________
From: "Steve Sampson" <steve(at)lbho.freeserve.co.uk>
Subject: Dynon Efis
Date: Jan 20, 2005
Kevin - thanks for that. I was testing the ASI the other day in the hanger by pressurising the pitot line and was amazed to see the Dynon compass swing quite aggressively. I guess it percieved it as an acceleration as the pressure came on and the software moved the compass to counteract the non existant acceleration error. (It was facing about 240)I think that clears that up. This is a D10 with a remote compass and the software that was current last year at S&F. I dont have the version number to hand. Steve. RV9a 9036 G-IINI PS Have you tested your entire pitot system with the Dynon Pitot/AoA head on. I dont see how to do it because Dynon have a built in leak. Its very small but they have confirmed it is meant to be there. > I'd like to confirm one thing - did you have the Dynon EFIS connected to the pitot and static systems? The reason I ask is that I understand that they use the airspeed input to partially correct for acceleration errors. The unit might behave strangely if it saw accelerations but no airspeed. Thanks for the Dynon report. -- Kevin Horton RV-8 (finishing kit) Ottawa, Canada -- Checked by AVG Anti-Virus. ________________________________________________________________________________
From: "Malcolm Thomson" <mdthomson(at)attglobal.net>
Subject: Re: 1/4 wave groundplane?
Date: Jan 20, 2005
Bob, I have been given some conflicting information regarding "ground planes" and this post leaves me still more confused about this business of ground planes. I have an airplane which is nearly all carbon. Unlike fiberglass, I am told that all antenna's must be on the outside of the carbon structure just like you would place them on an metal airplane. The basis for this is that "carbon acts like metal and does not let the radio frequencies through". With this said, one might assume then that the carbon will also act as a ground plane but I am also told that it does not. So, do I need to add a ground plane? If so, what would be the approach? Should I install some thin aluminum inside the aircraft, mount the antenna's on the outside, their bolts passing through the carbon and aluminum thereby making the electrical connection to the ground plane? What is the smallest ground plane you'd recommended for a COM antenna and does the antenna have to be mounted in the middle of it? Thanks Malcolm. -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L. Nuckolls, III Subject: AeroElectric-List: Re: 1/4 wave groundplane? --> > > >Oops! That was meant to go to aeroelectric > > > -----Original Message----- > > From: Steve Sampson [mailto:Steve(at)lbho.freeserve.co.uk] > > Sent: 19 January 2005 18:09 > > To: RV Squadron (E-mail) > > Subject: [rvsqn] 1/4 wave groundplane > > > > Bob - I would welcome your comments. > > > > In the bumph the PFA (roughly the British EAA) gives out there is > > some stuff about aerials. It includes...... > > > > "Even some professional radio installers seem to think that if the > > braid of the feeder coax is firmly connected to the metal fuselageat > > the base of the aerial, then it will do the job. Wrong! At any given > > frequency the length of the driven element ...is calculated to be > > resonant as a 1/4 wavelength................................But the > > 'counterpoise' or other half must also be of similar dimensions so > > as to present the trans/rec witha 1/2 wavelength total. The entire > > fuselage however presents no such thing and completely unbalances > > the system................causing a variety of problems, not least > > interference and much degraded performance........ At the base of > > the aerial the braid should also be connected to a tuned groundplane > > either in the form of a down going insulated wire or number of wires > > measuring 5% less in length than the driven > > element..........................It doe not matter that the airframe > > is also connected at its centre..................the oscilating > > pulses in the aerial will choose the resonant path both > > ways........................................." > > > > What is your reaction to this? I have never seen this reccomendation > > before. He seems to be trying to turn a 1/4 wave into a dipole with > > half the aerial inside and half outside. Surely this would cause > > energy to bounce around inside a metal aircraft? The writer is not "wrong" but he's making a mountain out of a molehill. An airplane is not a perfect world for antennas. Further, his concerns for "degraded performance" generally don't surface as significant realities. VHF Comm antennas have been installed on aircraft for over 60 years. Installations range from nearly ideal (antenna sits on large area of metal "radiating" several wavelengths in all directions. 747s and their like make really good airborne antenna farms. As the airplane gets smaller, the real estate for ground plane goes down. As the airplane becomes fabric over tube, opportunities for using existing features on the airplane as a ground plane or "counterpoise" degrades further and ultimately becomes non-existent on the glass-n- plastic machines. Yes, if you went to the antenna range and quantified performance of the various compromise antennas that have flown on ultra-lights through 747s, one could cheer the data plots on the 747 installation and cry in lots of beer over the results of tests for the ultra-light. Let us consider the most compromised antenna of all - the "rubber duckie" common to bizillions of hand held radios ranging from CB frequencies (27 Mhz) to near microwave (wi-fi products at 5 Ghz). NONE of these products are favored with anything like the ideal antenna when it comes to ground planes. Your hand-held vhf comm transceiver not only has a foreshortened antenna (it should be 23.6 inches long), it has only your very small body capacity to couple thorough to approach anything like a useful ground plane. Bottom line for USEFULNESS of ANY antenna installation is whether or not it serves the intended purpose while avoiding interference with other systems (some folks can use the outside-antenna comm transceiver with no problems while hand-held comm with rubber-duck in cockpit drives some panel mounted stuff zonkers). I've often remarked here on the list about the disparity of comments on Bob Archer's wing tip comm antennas (VERY compromised). One user says, "piece of crap" while another says, "greatest thing since sliced bread". Turns out that one guy never needs to talk to stations more than 10 miles away and the other guy was gunching about not hitting an RCO 40 miles away while he was flying 2000 feet above the terrain. We KNOW that a hand-held performs MUCH better plumbed into the ship's external antenna (no matter how compromised) than it does using just a rubber-duck from the cockpit. However, I'm not going to pitch the rubber-ducks on my hand-helds in favor of an "ideal" antenna with an optimal ground plane. This umbrella sized device would be difficult to open and use in the cockpit. All this stuff applies only to resonant, un-amplified antennas that drive low impedance feedlines (50 ohm coax). There's a whole other world of antennas like amplified GPS antennas, loran antennas, ADF antennas, AM antenna on your car, etc. which are e-field receptors and have their own special worlds that do not (indeed some cannot) depend on any kind of resonant counterpoise or ground plane. The writer was perfectly founded in the physics of the ideal antenna structure but appears unaware of the practical realities of antenna compromise that have performed to the degree EXPECTED and ACCEPTED on airplanes of all sizes for for decades. He may be familiar with the efforts that antenna designers expend to get the most from a broadcast or ground based communications antenna where the GOAL is ANTENNA performance. Our goal is to optimize FLIGHT SYSTEM performance wherein most situations will tolerate "degraded" antenna performance. Please feel free to forward this note to the original author and invite him to join us here on the List. Bob . . . ________________________________________________________________________________
From: "Rob Logan" <rob(at)logan.com>
Subject: Re: Odyssey Battery
Date: Jan 20, 2005
> http://www.batterymart.com/c-odyssey.html this lists the PC680 as Length 7 in. Width 3 1/16 in. Height 6 5/8 in. but has a link to http://www.batterymart.com/pdf_files/odyssey_guide.pdf that lists the PC680 as 7.27" 3.11" 6.67" so I'm still confused.... how big is a PC680? will it fit in a box I made for a B&C 16Ah battery? Rob ________________________________________________________________________________
From: "Rob Logan" <rob(at)logan.com>
Subject: Re: 1/4 wave groundplane?
Date: Jan 20, 2005
> What is the smallest ground plane you'd recommended for a COM antenna > and does the antenna have to be mounted in the middle of it? mounted my antennas to the outside carbon, but attached 4 copper radials (striped house wire) to the nut plates... the length of the ground planes isn't nearly as critical as the vertical. what matters is the SWR, or reflected energy back into the radio, this can be adjusted by coax feed length if you can't cut your floxed in radials like me. http://mars.comportco.com/~w5alt/antennas/notes/ant-notes.php?pg=22 > The writer is not "wrong" but he's making a mountain out of > a molehill. An airplane is not a perfect world for antennas. 4 radials of "close" size are easy to glass in (3 would work, but more than 4 is overkill) and fine tune SWR with feed length.. no math required... one would notice loss of impedance fuel level converters for 30secs long before the tower asks you to "say again" -Rob ________________________________________________________________________________
From: "Steve Sampson" <steve(at)lbho.freeserve.co.uk>
Subject: Re: 1/4 wave groundplane?
Date: Jan 20, 2005
Bob - thanks for that. As I thought, theoretically correct but not pragmatic. The story of so much in UK engineering in the last 60 years. Steve. -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Robert L. Nuckolls, III Subject: AeroElectric-List: Re: 1/4 wave groundplane? -- Checked by AVG Anti-Virus. ________________________________________________________________________________
Date: Jan 20, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: 1/4 wave groundplane?
> > >Bob, I have been given some conflicting information regarding "ground >planes" and this post leaves me still more confused about this business >of ground planes. > >I have an airplane which is nearly all carbon. Unlike fiberglass, I am >told that all antenna's must be on the outside of the carbon structure >just like you would place them on an metal airplane. The basis for this >is that "carbon acts like metal and does not let the radio frequencies >through". Correct . . . > With this said, one might assume then that the carbon will >also act as a ground plane but I am also told that it does not. . . . sorta correct. We tried using carbon fiber as ground plane on several projects and abandoned the idea. It's EASY to add a good ground plane in most cases . . . so why not? >So, do I need to add a ground plane? If so, what would be the approach? >Should I install some thin aluminum inside the aircraft, mount the >antenna's on the outside, their bolts passing through the carbon and >aluminum thereby making the electrical connection to the ground plane? >What is the smallest ground plane you'd recommended for a COM antenna >and does the antenna have to be mounted in the middle of it? The ground plane is easiest to fabricate and install if you cut strips of aluminum or copper foil about 1" wide and 22 inches long. RADIATE minimum of 4, maximum of 8 radials from base of antenna on inside of fuselage. Run along contours. If you have to "hop" over structure or stiffeners, don't change length of material, just run it, secure it with adhesive and let it be. The radials should connect to a common plate under the footprint of the antenna. If you make the plate out of brass and the radials out of brass shim stock, all can be neatly soldered together at the center. On a graphite airplane, a solid pieced of brass shim stock conformed to the inside contours for as far as practical in each direction with a max desired dimension of 22" from base of antenna would be an attractive compromise too. Other antennas are built the same way . . . transponder antennas can use a full circular disk of brass or aluminum, 5.2" in diameter. See chapter on antennas in the 'Connection. Now, if for some reason you can only get three or two radials installed, the thing will probably do just fine anyhow. Antennas on airplanes can be VERY poor compared to the best-we-know-how-to- do and still function adequately. Bob . . . ________________________________________________________________________________
From: "Malcolm Thomson" <mdthomson(at)attglobal.net>
Subject: Re: 1/4 wave groundplane?
Date: Jan 20, 2005
Bob, how significant is the use of brass vs. aluminum? Thanks. -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L. Nuckolls, III Subject: RE: AeroElectric-List: Re: 1/4 wave groundplane? --> > > >Bob, I have been given some conflicting information regarding "ground >planes" and this post leaves me still more confused about this business >of ground planes. > >I have an airplane which is nearly all carbon. Unlike fiberglass, I am >told that all antenna's must be on the outside of the carbon structure >just like you would place them on an metal airplane. The basis for >this is that "carbon acts like metal and does not let the radio >frequencies through". Correct . . . > With this said, one might assume then that the carbon will also act >as a ground plane but I am also told that it does not. . . . sorta correct. We tried using carbon fiber as ground plane on several projects and abandoned the idea. It's EASY to add a good ground plane in most cases . . . so why not? >So, do I need to add a ground plane? If so, what would be the approach? >Should I install some thin aluminum inside the aircraft, mount the >antenna's on the outside, their bolts passing through the carbon and >aluminum thereby making the electrical connection to the ground plane? >What is the smallest ground plane you'd recommended for a COM antenna >and does the antenna have to be mounted in the middle of it? The ground plane is easiest to fabricate and install if you cut strips of aluminum or copper foil about 1" wide and 22 inches long. RADIATE minimum of 4, maximum of 8 radials from base of antenna on inside of fuselage. Run along contours. If you have to "hop" over structure or stiffeners, don't change length of material, just run it, secure it with adhesive and let it be. The radials should connect to a common plate under the footprint of the antenna. If you make the plate out of brass and the radials out of brass shim stock, all can be neatly soldered together at the center. On a graphite airplane, a solid pieced of brass shim stock conformed to the inside contours for as far as practical in each direction with a max desired dimension of 22" from base of antenna would be an attractive compromise too. Other antennas are built the same way . . . transponder antennas can use a full circular disk of brass or aluminum, 5.2" in diameter. See chapter on antennas in the 'Connection. Now, if for some reason you can only get three or two radials installed, the thing will probably do just fine anyhow. Antennas on airplanes can be VERY poor compared to the best-we-know-how-to- do and still function adequately. Bob . . . ________________________________________________________________________________
From: <tgrazian(at)bellsouth.net>
Subject: Switching GPS Data Signals
Date: Jan 20, 2005
I am currently wiring the panel for my Zodiac 601XL. I am installing a Trio EZ Pilot II autopilot, which accepts NMEA 0183 signals for tracking. I also have on order a Blue Mountain EFIS Lite Gen 3, which has a built in GPS. I would like to be able to use my Garmin 295 and the EFIS Lite to supply the GPS data. Does anyone have any comments on the advisability of using a "2-8" type DPDT switch to change the GPS data in/out from the above two sources? I have no idea if putting the signals through a switch would result in unacceptable signal loss. Tony Graziano Zodiac 601XL; N493TG ________________________________________________________________________________
Date: Jan 20, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Effects of feedline length on Standing Wave Ratio
> > What is the smallest ground plane you'd recommended for a COM antenna > > and does the antenna have to be mounted in the middle of it? > >mounted my antennas to the outside carbon, but attached 4 >copper radials (striped house wire) to the nut plates... the >length of the ground planes isn't nearly as critical as >the vertical. what matters is the SWR, or reflected energy >back into the radio, this can be adjusted by coax feed >length if you can't cut your floxed in radials like me. >http://mars.comportco.com/~w5alt/antennas/notes/ant-notes.php?pg=22 > > > The writer is not "wrong" but he's making a mountain out of > > a molehill. An airplane is not a perfect world for antennas. >4 radials of "close" size are easy to glass in (3 would work, but >more than 4 is overkill) and fine tune SWR with feed length.. no >math required... one would notice loss of impedance fuel level >converters for 30secs long before the tower asks you to "say again" Antenna feedline has no effect on SWR. When SWR is very poor, the transmitter may be HAPPIER attempting to transfer energy to the antenna/feedline system but SWR is SWR is SWR. The PRIMARY effect on SWR is overall length of the radiating element . . . i.e. the antenna itself. SECONDARY effects that stack on top of each other is the sum of the reactances of what purports to be a 'ground plane' combined with any attempts with lumped constant inductors and capacitors to optimize the 1/4-wave antenna feed-point impedance to 50 ohms. It naturally falls close to 35 ohms. It's always a good thing to do an SWR plot of a multi-frequency antenna (COMM runs 118-135 MHz) and see if the SWR is MINIMUM near the center of the range of interest (126.5) and that it doesn't get outrageously high at the ends. SWR of 3:1 is generally quite acceptable. It may be that minimum occurs somewhere OTHER than right in the middle but as long as it's less than 3:1 over the range, the antenna is at least a reasonable LOAD for energies put out by the transmitter. This says NOTHING about the antenna's efficiency as a radiator (and conversely a receptor) of radio frequency energies. One WISHES that the whole 50 ohms impedance of a 1:1 antenna also represents its RADIATION resistance as well. Never quite so. Very sad antennas can have RADIATION resistances in the 1-10 ohm range while the rest is resistive losses. A 50 ohm resistor has an impedance of 50 ohms but a radiation resistor in the milliohms range. This is why they make good "DUMMY LOADS". See: http://www.aeroelectric.com/Pictures/DummyLoad.jpg . . . this is a VERY poor antenna but the transmitter doesn't know it. SWR is 1:1 but it radiates little or nothing. Be very suspicious of any instructions suggesting that you "adjust the length of the feedline for improved matching or reduction of SWR". This is a big red flag that says something is seriously wrong with the design of the antenna and/or feedline system. Bob . . . ________________________________________________________________________________
Date: Jan 20, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: 1/4 wave groundplane?
> > >Bob, how significant is the use of brass vs. aluminum? Brass and copper can be soldered to . . . VERY long lived joints. Aluminum is an acceptable performer but must be "fastened" with high pressure methods to achieve and maintain gas-tight joints over the lifetime of the airplane. If you must use aluminum, I'd rivet the radials on. When a rivet swells in the properly sized hole . . . it's about as gas tight as you can get . . . but my personal preference is for copper or brass. I just LUV soldering things together. Bob . . . ________________________________________________________________________________
Date: Jan 20, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Switching GPS Data Signals
> >I am currently wiring the panel for my Zodiac 601XL. I am installing a >Trio EZ Pilot II autopilot, which accepts NMEA 0183 signals for >tracking. I also have on order a Blue Mountain EFIS Lite Gen 3, which has >a built in GPS. I would like to be able to use my Garmin 295 and the EFIS >Lite to supply the GPS data. > >Does anyone have any comments on the advisability of using a "2-8" type >DPDT switch to change the GPS data in/out from the above two sources? I >have no idea if putting the signals through a switch would result in >unacceptable signal loss. Digital signals are essentially "lossless" . . . and dependent on how much LOAD the receiving device places on the transmitting device. My designs are always robust with respect to the transmitter. My gizmos can "talk" to dozens of devices interested in serial data with no degradation. When you have multiple transmitters or sources, then some kind of either-or switching arrangement is in order. Given that most GPS data is one-way (meaning that it's simply spewed out with no regard for how the receiving equipment is accepting it) a simple single pole, two position switch (1-3) should suffice to select between the two sources. All the grounds can run together and the switch used to select which source signal line drives the receivers. Bob . . . ________________________________________________________________________________
Date: Jan 20, 2005
From: rv-9a-online <rv-9a-online(at)telus.net>
Subject: Re: Switching GPS Data Signals
One issue with the Garmin 295 is (I believe) that it's serial output does not put out true-RS-232C signal levels, but rather TTL level signals. Normally, this should not be a problem, but it may may make the GPS serial data signals more susceptible to interference. Level converters are available to fix this, send me an email off-line if you are interested and I'll send you a link. Vern Little, RV-9A tgrazian(at)bellsouth.net wrote: > >I am currently wiring the panel for my Zodiac 601XL. I am installing a Trio EZ Pilot II autopilot, which accepts NMEA 0183 signals for tracking. I also have on order a Blue Mountain EFIS Lite Gen 3, which has a built in GPS. I would like to be able to use my Garmin 295 and the EFIS Lite to supply the GPS data. > >Does anyone have any comments on the advisability of using a "2-8" type DPDT switch to change the GPS data in/out from the above two sources? I have no idea if putting the signals through a switch would result in unacceptable signal loss. > >Tony Graziano >Zodiac 601XL; N493TG > > > > ________________________________________________________________________________
From: "Turbo Tom" <turbotom(at)mindspring.com>
Subject: Bent whip "radiators" question
Date: Jan 20, 2005
> > See: http://www.aeroelectric.com/Pictures/DummyLoad.jpg > > . . . this is a VERY poor antenna but the transmitter > doesn't know it. SWR is 1:1 but it radiates little or > nothing. > That was very well-explaned, Bob! The super-low SWR but non-radiator illustration was outstanding. I for one, would like to know just what effects the bending of the typical 1/4-wave whip 'aft' would have on radiation [transmission and reception]. How do those composite streamlined "Commant" [sp] stack up against a straight or bent wire on the bottom of the fuselage of the typical RV? They all seem to work "OK", but do you have an opinion on which is best, or worse. I've seen quite a few bent wires lately that were swept completely aft, and not all that far from the belly. Are there practical differences? One last related question; if the antenna is mounted between the gearlegs, [mine are aluminum] does that have a real-world effect? TT RV-8 ATL GA ________________________________________________________________________________
From: "Brian Kraut" <brian.kraut(at)engalt.com>
Subject: Switching GPS Data Signals
Date: Jan 20, 2005
NMEA standard is RS-422, not 232, although it is quite common for devices to put out TTL levels which works fine. RS-422 is much more imune to noise than 232. RS-422 is a differential signal that goes to +5V on a logic 1 and -5V on a logic 0. TTL goes to +5V on a logic 1 and 0V on a logic 0. Since in their infinite wisdom the originators of NMEA decided to use a RS-422 transmitter as standard and an optocoupler as an input in this weird mismatched arrangement the -5V gets clipped to 0V by the optocoupler in the receiver end so it is essentially TTL anyway. Because some transmitters, including the devices I manufacture, use a real RS-422 driver where the A and B signal lines are isolated from ground and some use TTL with a ground reference I recommend using a double pole, double throw toggle switch to switch both sides of the signal simultaneously. The shields can all be tied together. While a single pole switch works almost all of the time, a double pole switch works every time. Some manufacturers also have a shield connection at the receive side of the signal, but it is normally common practice, in marine electronics anyway, to connect the shield only on the transmit side to prevent ground loops. Brian Kraut Engineering Alternatives, Inc. www.engalt.com -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of rv-9a-online Subject: Re: AeroElectric-List: Switching GPS Data Signals One issue with the Garmin 295 is (I believe) that it's serial output does not put out true-RS-232C signal levels, but rather TTL level signals. Normally, this should not be a problem, but it may may make the GPS serial data signals more susceptible to interference. Level converters are available to fix this, send me an email off-line if you are interested and I'll send you a link. Vern Little, RV-9A tgrazian(at)bellsouth.net wrote: > >I am currently wiring the panel for my Zodiac 601XL. I am installing a Trio EZ Pilot II autopilot, which accepts NMEA 0183 signals for tracking. I also have on order a Blue Mountain EFIS Lite Gen 3, which has a built in GPS. I would like to be able to use my Garmin 295 and the EFIS Lite to supply the GPS data. > >Does anyone have any comments on the advisability of using a "2-8" type DPDT switch to change the GPS data in/out from the above two sources? I have no idea if putting the signals through a switch would result in unacceptable signal loss. > >Tony Graziano >Zodiac 601XL; N493TG > > ________________________________________________________________________________
Date: Jan 20, 2005
From: rv-9a-online <rv-9a-online(at)telus.net>
Subject: Re: Switching GPS Data Signals
The Trio datasheet appears to allow either RS-422 single ended, RS-422 differential, RS-232, or perhaps even TTL inputs. Of these, the most robust would be RS-422 differential, but not many GPS devices provide it. Many devices (Garmin panel units for example) provide RS-232 levels (+/- 10 volts approx), and some (portable GPS) provide TTL levels. Of the last two, the RS-232 level is more noise immune (the marking level of -10V has about 11 volts of noise immunity, the spacing level of +10 volts around 8 volts of noise immunity). TTL levels, or single-ended RS-422 provide about 1 to 2 volts of noise immunity. These are estimates from memory, but you can see that single ended 5 Volt signals are not as robust as RS-232 levels. Differential RS-422 run as a twisted pair with a shield is the best.... but not common. What does this mean to Tony who's head is probably spinning right now? Not too much. Unless you are in a high electrical noise environment you can probably safely ignore the subtleties and just run your wires through the switches. If you have autopilot problems later, this would be one area to investigate, however. Vern Little Brian Kraut wrote: > >NMEA standard is RS-422, not 232, although it is quite common for devices to >put out TTL levels which works fine. RS-422 is much more imune to noise >than 232. > >RS-422 is a differential signal that goes to +5V on a logic 1 and -5V on a >logic 0. TTL goes to +5V on a logic 1 and 0V on a logic 0. Since in their >infinite wisdom the originators of NMEA decided to use a RS-422 transmitter >as standard and an optocoupler as an input in this weird mismatched >arrangement the -5V gets clipped to 0V by the optocoupler in the receiver >end so it is essentially TTL anyway. > >Because some transmitters, including the devices I manufacture, use a real >RS-422 driver where the A and B signal lines are isolated from ground and >some use TTL with a ground reference I recommend using a double pole, double >throw toggle switch to switch both sides of the signal simultaneously. The >shields can all be tied together. While a single pole switch works almost >all of the time, a double pole switch works every time. > >Some manufacturers also have a shield connection at the receive side of the >signal, but it is normally common practice, in marine electronics anyway, >to connect the shield only on the transmit side to prevent ground loops. > >Brian Kraut >Engineering Alternatives, Inc. >www.engalt.com > >-----Original Message----- >From: owner-aeroelectric-list-server(at)matronics.com >[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of >rv-9a-online >To: aeroelectric-list(at)matronics.com >Subject: Re: AeroElectric-List: Switching GPS Data Signals > > > > >One issue with the Garmin 295 is (I believe) that it's serial output >does not put out true-RS-232C signal levels, but rather TTL level >signals. Normally, this should not be a problem, but it may may make >the GPS serial data signals more susceptible to interference. Level >converters are available to fix this, send me an email off-line if you >are interested and I'll send you a link. > >Vern Little, RV-9A > >tgrazian(at)bellsouth.net wrote: > > > >> >>I am currently wiring the panel for my Zodiac 601XL. I am installing a >> >> >Trio EZ Pilot II autopilot, which accepts NMEA 0183 signals for tracking. I >also have on order a Blue Mountain EFIS Lite Gen 3, which has a built in >GPS. I would like to be able to use my Garmin 295 and the EFIS Lite to >supply the GPS data. > > >>Does anyone have any comments on the advisability of using a "2-8" type >> >> >DPDT switch to change the GPS data in/out from the above two sources? I >have no idea if putting the signals through a switch would result in >unacceptable signal loss. > > >>Tony Graziano >>Zodiac 601XL; N493TG >> >> >> >> > > > > ________________________________________________________________________________
From: "Mike Holland" <hollandm(at)pacbell.net>
Subject: Re: Z13a Pre-flight alt test procedure?
Date: Jan 20, 2005
Bob, I have the SD8, with indicator light and wired per Z13. What problem is there with having both alternators active? If the SD8 will come on-line at idle speed the indicator light would go out and that would indicate it was active without having to shut down the main alternator. If it matters I have Hall effect sensors on both B leads. Thanks ________________________________________________________________________________
Date: Jan 21, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Bent whip "radiators" question
> > > > > > See: http://www.aeroelectric.com/Pictures/DummyLoad.jpg > > > > . . . this is a VERY poor antenna but the transmitter > > doesn't know it. SWR is 1:1 but it radiates little or > > nothing. > > >That was very well-explaned, Bob! The super-low SWR but non-radiator >illustration was outstanding. > >I for one, would like to know just what effects the bending of the typical >1/4-wave whip 'aft' would have on radiation [transmission and reception]. >How do those composite streamlined "Commant" [sp] stack up against a >straight or bent wire on the bottom of the fuselage of the typical RV? > >They all seem to work "OK", but do you have an opinion on which is best, or >worse. I've seen quite a few bent wires lately that were swept completely >aft, and not all that far from the belly. Are there practical differences? Not many. The WORKING portion of the antenna is where the greatest currents are flowing in the radiator. For the 1/4-wave whip, this is at the base. Current diminishes to zero at the tip. The antenna needs to look ELECTRICALLY like a full 1/4-wave conductor for it to match the feedline and accept power. However, it may be PHYSICALLY shorter and still function well. For example, my first mobile radio installation in a '41 Pontiac used an 11' whip with a loading coil about 3' up from the bottom. The loading coil made the antenna look 32' long ELECTRICALLY while keeping the physical length much less. As for functionality, the bottom 3' section was doing most of the work. I could have made the coil larger and the top section much shorter and not materially impact efficiency. The laid-back whips on comm antennas are fine. They don't even use loading (rubber ducks get so small by doing CONTINUOUS loading. Most of the antenna is coiled wire wraped around a core). >One last related question; if the antenna is mounted between the gearlegs, >[mine are aluminum] does that have a real-world effect? Sure. You don't event want to know what it does to the radiation pattern of your antenna. But does it prevent the antenna from doing what you need it to do? Probably not and only in occasional instances that go away when you change course. Bob . . . ________________________________________________________________________________
Date: Jan 21, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Effects of feedline length on Standing Wave Ratio -
Corrected The first paragraph of my reply was incomplete. I've added the necessary words in THIS version: > > What is the smallest ground plane you'd recommended for a COM antenna > > and does the antenna have to be mounted in the middle of it? > >mounted my antennas to the outside carbon, but attached 4 >copper radials (striped house wire) to the nut plates... the >length of the ground planes isn't nearly as critical as >the vertical. what matters is the SWR, or reflected energy >back into the radio, this can be adjusted by coax feed >length if you can't cut your floxed in radials like me. >http://mars.comportco.com/~w5alt/antennas/notes/ant-notes.php?pg=22 > > > The writer is not "wrong" but he's making a mountain out of > > a molehill. An airplane is not a perfect world for antennas. >4 radials of "close" size are easy to glass in (3 would work, but >more than 4 is overkill) and fine tune SWR with feed length.. no >math required... one would notice loss of impedance fuel level >converters for 30secs long before the tower asks you to "say again" Antenna feedline length has no effect on SWR. When SWR is very poor, the transmitter may be HAPPIER attempting to transfer energy to the antenna/feedline system by adjusting the length of the feedline. This simply means that you've moved the transmitter's position on a "standing wave" from a low current, high voltage point to a higher current, low voltage point. But SWR is SWR is SWR. The PRIMARY effect on SWR is overall length of the radiating element . . . i.e. the antenna itself. SECONDARY effects that stack on top of each other is the sum of the reactances of what purports to be a 'ground plane' combined with any attempts with lumped constant inductors and capacitors to optimize the 1/4-wave antenna feed-point impedance to 50 ohms. It naturally falls close to 35 ohms. It's always a good thing to do an SWR plot of a multi-frequency antenna (COMM runs 118-135 MHz) and see if the SWR is MINIMUM near the center of the range of interest (126.5) and that it doesn't get outrageously high at the ends. SWR of 3:1 is generally quite acceptable. It may be that minimum occurs somewhere OTHER than right in the middle but as long as it's less than 3:1 over the range, the antenna is at least a reasonable LOAD for energies put out by the transmitter. This says NOTHING about the antenna's efficiency as a radiator (and conversely a receptor) of radio frequency energies. One WISHES that the whole 50 ohms impedance of a 1:1 antenna also represents its RADIATION resistance as well. Never quite so. Very sad antennas can have RADIATION resistances in the 1-10 ohm range while the rest is resistive losses. A 50 ohm resistor has an impedance of 50 ohms but a radiation resistor in the milliohms range. This is why they make good "DUMMY LOADS". See: http://www.aeroelectric.com/Pictures/DummyLoad.jpg . . . this is a VERY poor antenna but the transmitter doesn't know it. SWR is 1:1 but it radiates little or nothing. Be very suspicious of any instructions suggesting that you adjust the length of the feedline for "improved matching" or "reduction of SWR". This is a big red flag that says something is seriously wrong with the design of the antenna and/or feedline system. Bob . . . -------------------------------------------------------- < Throughout history, poverty is the normal condition > < of man. Advances which permit this norm to be > < exceeded -- here and there, now and then -- are the > < work of an extremely small minority, frequently > < despised, often condemned, and almost always opposed > < by all right-thinking people. Whenever this tiny > < minority is kept from creating, or (as sometimes > < happens) is driven out of a society, the people > < then slip back into abject poverty. > < > < This is known as "bad luck". > < -Lazarus Long- > <------------------------------------------------------> http://www.aeroelectric.com ________________________________________________________________________________
Date: Jan 21, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Z13a Pre-flight alt test procedure?
> >Bob, I have the SD8, with indicator light and wired per Z13. What problem >is there with having both alternators active? No, won't hurt a thing. > If the SD8 will come on-line at idle speed the indicator light would go > out and that would indicate it was active without having to shut down the > main alternator. The light goes out when you flip the switch to ON and there is no OV condition present. The absence of that light is NOT and indicator of PROPER operation but the presence of the light is solid indication of alternator OFF. >If it matters I have Hall effect sensors on both B leads. Does your alternator have a built in regulator. Are you wired per Z-24? IF NOT . . . then there's nothing at risk for turning the main alternator OFF and aux alternator ON during runup to check your ignition system(s). If you have Z-24 and internally regulated alternator, turn the main alternator OFF and aux alternator ON at engine idle before runup . . . after run up and at engine idle, turn aux alternator OFF and main alternator back ON. Don't concern yourself with voltage readings while aux alternator is ON . . . just not that the current output comes up. You might want to consider running BOTH alternator leads through ONE hall-effect sensor. Since the alternators are tested/used independently from each other, the one current sensor can be used to monitor functionality of both alternators. Bob . . . ________________________________________________________________________________
Date: Jan 21, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Modified Z-12 comments
> > >I had a similar response to a very similar question a few weeks back. I >wanted to know if my method if integrating the Z-30 dual battery with >the Z-13 'All Electric Airplane on a Budget' would work well or not. > >See: >AeroElectric-List: RE: Schematic Review >It's message number 21455. >I don't know how to link to it. > >I got one response from another list user but it seemed pretty clear >that 'battery failure' has been discussed before and isn't a topic that >needs to be rehashed. The batteries are infallible and failure is as >likely as the prop coming off. > Your question isn basically the same how >is it best to integrage Z-30 with the various diagrams? > >I'm still curious why Z-30 exists if properly maintained RG batteries >never fail. A dual alternator, single battery system should be just as >reliable as a dual battery dual alternator system. With the exception >of a twin engine which could use dual batteries for cabling reasons, I >don't know what reasons could be construed for a dual battery >installation. A PROPERLY MAINTAINED battery has a very low probability of failure. Properly maintained means making sure that a battery is not taxed to duty beyond some minimum value of capacity . . . LOOOOONNNNGGG before it stops cranking the engine. This is done by either (1) periodic and frequent change-out or (2) periodic capacity testing. The philosophy you choose is driven by your perceptions of $time$ invested in reliability. Dual batteries allow one to mitigate probability of CONNECTION failure to a perfectly good battery. If you have an electrically dependent engine with TWO sets of electrically driven support hardware, you MAY wish to mitigate single points of failure in common wiring by having two independent batteries supplying power to EACH of two systems. The concept of installing two batteries has little to do with gross battery reliability. We've had cases where wiring has become disconnected and battery posts were broken off (stiff 2AWG 22759 jumpers). THESE are greater risks easily handled with dual batteries and dual battery busses to support dual engine support systems. >In the particular aircraft configuration I am working with, we have dual >electronic ignitions and limited weight carrying capability aft of the >firewall (canard). I can't slap an SD-20 on there as a backup, it's >simply getting too heavy. An SD-8 is the lightest backup I can get, but >it doesn't meet the current requirements to power both ignitions (6A) >plus the essential bus. Why run BOTH ignitions in the endurance mode? The engine runs just fine with ONE ignition . . . when the main alternator is unavailable, I'd shut down one of the ignition systems too. Remember, all you need to have running are the gizmos that keep you airborne and pointed in the right direction until time for approach to landing. With an SD-8, 99% of airplanes flying should be able to keep 100% of the battery's capacity in reserve for approach to landing. > I need a large battery up front to supplement >current to provide electrical power for the long range the aircraft is >capable of. I would also like to add 'Replace and Rotate batteries' to >the annual maintenance task list. This will simplify maintenance for >myself or whoever else may own the aircraft. How large is "large"? >If the aircraft was ever sold, and had one battery, it would be much >easier for a third party to later rationalize not replacing a large >battery after only 1 year. It also seems likely to me that even though >I would stress how important proper battery maintenance is, that the >battery would might not be properly maintained with bi-annual capacity >checks and timely replacement. I see two batteries as a simplification >of maintenance. Two, smaller batteries also provide protection in the >event that some future user replaces them with some other type of >battery that is more prone to failure. Why agonize over a future buyer's PERCEPTIONS of a design and established operating/maintenance requirements. If it's in the POH and maintenance procedures and has served one well for many years, (1) the new owner can either accept it without understanding it (that's how 90% of the spam can drivers do it) or (2) one can explain how and why the system was designed this way and offer him UNDERSTANDING or (3) he can get out the hammers-n-saws and make it work any way he likes. Let's hear it for liberty and the freedom to do dumb things. >In the configuration that you are describing James I think that having >to use the circuit breakers as switches to perform battery isolation >complicates things from a usability point of view. When I integrated >Z-30 with Z-13 I didn't eliminate any switches, and it is a very simple >system to use, although it does take a bit more panel space. Can we backtrack and see what mission requirements and equipment compliments drove the architecture decision in the first place? Then start with a Z-13/Z-30 combo and discuss whatever shortcomings have been discovered? A discussion on total battery weight would be useful too. I'm mystified by the term "large" battery to support mission requirements when there are two alternators. Bob . . . ________________________________________________________________________________
Date: Jan 21, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Apex (Raleigh) NC Seminar Date Set
We've just concluded preparations for offering a weekend seminar in the facilities of EAA Chapter 1114 in Apex NC near Raleigh. Interested individuals are invited to check out the details at: http://aeroelectric.com/seminars/ApexNC.html Bob . . . -------------------------------------------------------- < Throughout history, poverty is the normal condition > < of man. Advances which permit this norm to be > < exceeded -- here and there, now and then -- are the > < work of an extremely small minority, frequently > < despised, often condemned, and almost always opposed > < by all right-thinking people. Whenever this tiny > < minority is kept from creating, or (as sometimes > < happens) is driven out of a society, the people > < then slip back into abject poverty. > < > < This is known as "bad luck". > < -Lazarus Long- > <------------------------------------------------------> http://www.aeroelectric.com ________________________________________________________________________________
Date: Jan 21, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Microlight battery sizing
> > >Hi > >I have recently bought a microlight project which includes a Kawasaki >440 (26 cu in) engine with alternator and electric start. > >I'm trying to figure out what size battery I should buy... The >documentation I've found on the engine says that I need a battery >capable of delivering 18A or so cranking current. That seems a little light in spite of the engine's small size. Was the document suggesting an 18 a.h. battery? These are plentiful in MANY brands. They're about 3 x 6 x 6 inches, weigh about 15 pounds and are very reasonable in cost. Some folks sell these for $40 or less. > I guess that's >reasonable, since BobN uses a figure of 250A for (I guess) something >like an O320, which is 10 times as big. > >BobN recommends a RG type as providing better cranking current than a >standard flooded cell battery. > >There's really no essential electrical load... the only electrical >equipment is a handheld radio, perhaps a GPS, perhaps an MP3 player... >all of them can run off batteries. > >I've found a cheap CGB brand (made in China, 12V 7Ah) RG battery for >sale. A Net search showed up 25 milli-ohms internal resistance for this >battery. Is this going to be suitable? Suitability is in the experience of the beholder and difficult to predict given what we DON'T know about the battery you're referring to. Try it. If you don't like it get a different one. Bob . . . ________________________________________________________________________________
Date: Jan 21, 2005
Subject: Rotary Switch- solution found
From: Bonnie & August Lehmann <blehmann(at)pris.bc.ca>
Just to say thank you to Leo Corbalis, Rob Prior, and Sigmo for their leads and suggestions to a replacement of a 25A, 120VAC rotary selector switch. None of the sources had anything of a high enough capacity, and as a total greenhorn in electrical or electronic matters, I hesitated going the relay/contacter route. Then my better half came up with a solution after she examined the broken switch, and that was to use parts of a sheet of Lexan I happen to have laying around to replace the broken face of the switch. A full day later, and voila, its repaired and working! Now we will survive the early stages of the 37th ice age this year. Many thanks to the List and the rapid responses it created to our dilemma. August ________________________________________________________________________________
Date: Jan 22, 2005
From: Frank & Dorothy <frankv(at)infogen.net.nz>
Subject: Battery failure -- lessons and questions
on dbmail-mx1 Hi, Thought you guys might benefit from my experience today with my car battery (at an air show, so it is aviation related :-) And there are some bits of what I think are aeroelectric technology information. Anyone not wanting to read my screeds should skip directly to LESSONS. I recently installed an engine immobiliser after my car disappeared overnight a couple of times (the plane project is in the garage). When the car wouldn't start a couple of times over the last month or two, I put it down to a not-too-well setup cheap immobiliser. When the car started after a couple of twiddles with the immobiliser wires, that confirmed it. Today though, at an airshow about 2 hours drive from home, it wouldn't crank again. :-( :-( Just a buzzing series of clicks from the immobiliser relay. Twiddled the wires. Still no go. Tried the electric windows -- they went down OK, but still no cranking. Disconnected the immobiliser entirely. No help. Hmmm... borrowed some jumper leads, and persuaded the guy on the next-door car in the parking lot to help out with his alternator and battery. No go. Turning the key resulted in the dash waring lights all going out. Now, this was really surprising. someone came along with a diesel-powered car with a *big* battery... STILL no go. By now, I'd decided that there was probably a fault in the starter motor or ring gear :-( The kibbitzers (when waiting in a queue to get out of an airfield carpark after a show, any entertainment is welcome) and the hassle of somehow getting home, and then coming back the next day or even 2 days later, it being a holiday on Monday) eventually persuaded me to try a new battery. I got a ride to the nearest gas station, bought a battery (at an exorbitant price) and borrowed a couple of spanners, and got back to the airfield and replaced the battery. Somewhat to my surprise, everything suddenly worked properly! As I see it now, when the starter motor isn't turning, its coils have less impedance/resistance than the rest of the circuitry in the car. Hence, turning the key to 'start' would drop the voltage across the warning lights so that they went out. But the battery couldn't provide enough oomph to turn the starter motor, so from the battery's point of view there was more or less a short circuit. I'm thinking that probably one (or more) of the battery's cells has died, so the battery couldn't provide 12.5V, and some reduced amount of current. (I kept the bad battery, and will investigate it with voltmeter, etc tomorrow) I still don't see why adding more oomph via external battery and jumper leads didn't get the car started. I guess that somehow the dead cell in the bad battery was providing some kind of low-resistance path for the juice from the good battery to flow through, instead of through the starter motor??? But there was no noticeable heating of the jumper leads, or loading down of the running car which I'd expect in that situation. Also, I'd expect (but didn't see) sparks when I attached the last jumper leads. Another question that I'm wondering about: How can putting jumper leads on a car blow its computer (as I was warned about today)? Surely, from the computer's point of view, it can't tell whether the flow of electricity its receiving is coming from the car's own battery, an external battery, or some combination of both? If 'surges of electricity' are the culprit as someone contended today, then surely disconnecting a near-dead battery and connecting a new fully-charged battery is worse than jumpering the full battery across the near-dead one? And what about the voltage transients when the alternator starts up? Is this "putting jumper leads on a car blow its computer" just a myth? BobN, I'd appreciate it if you would satisy my curiosity over the physics of what happened today. LESSONS: 1. When your battery suggests that it is about to die, take heed! 2. Somehow, a bad battery can prevent a parallel good battery from working! This may be especially relevant for people installing dual batteries in their aircraft -- if you can't isolate a bad battery, it may prevent starting (or even take down the electrical system???) even if you have a good battery (or perhaps even a running alternator???) alongside. Frank ________________________________________________________________________________
From: KITFOXZ(at)aol.com
Date: Jan 22, 2005
Subject: Re: Battery failure -- lessons and questions on dbmail-mx1
In a message dated 1/22/2005 5:38:12 A.M. Eastern Standard Time, frankv(at)infogen.net.nz writes: LESSONS: 1. When your battery suggests that it is about to die, take heed! 2. Somehow, a bad battery can prevent a parallel good battery from working! This may be especially relevant for people installing dual batteries in their aircraft -- if you can't isolate a bad battery, it may prevent starting (or even take down the electrical system???) even if you have a good battery (or perhaps even a running alternator???) alongside. Frank Hello Frank, Your lesson # 1 is so very true! This is one reason that Bob always preaches about replacing aircraft batteries on a regular interval. The battery is the most unpredictable component in your aircraft, and yet the most depended upon. An old battery can have a shorted cell, thus reducing the battery's voltage to 10 volts. A jumper battery connected in parallel across this bad 10 volt battery will often be unable to boost the system voltage enough to start your engine. This is why it is a good idea to remove the battery in question from the circuit, if a jump fails to get you going, and replace it with a known good battery. An old battery with a shorted cell will receive full charge current from the charging system too as the voltage regulator pushes tons of current into this bad battery trying to restore its voltage to 13.8. The excess charge current will destroy the other cells in a short time. I have never liked using an "immobilizer" type of device in any of my cars for fear that the thing would fail to "make" my starting circuit on a cold and rainy night. The shops that install them often use any number of poor connection practices as they install these bottom dollar devices. I prefer to not have my starting circuit compromised in any way. A simple noise maker alarm system is my choice. If the thief defeats the alarm or drives off with it screaming, I say let it be. Any electronic theft deterrent is just that in my opinion, a deterrent. The average thief is dumb and in a hurry for an easy victim. Sure there are the pros out there working for chop shops and those few guys will know how to start your car no matter what you have installed to foil them. John P. Marzluf Columbus, Ohio Kitfox Outback (out back in the garage) ________________________________________________________________________________
Date: Jan 22, 2005
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: 11868 Linderman
>Below is the result of your inquiry. It was submitted by >Lucas Linderman (linluc23(at)email.pct.edu) on Friday, January 21, 2005 at >20:24:58 > >Friday, January 21, 2005 > >Lucas Linderman > >, >Email: linluc23(at)email.pct.edu >Comments/Questions: Mr. Nuckolls, > My name is Luke Linderman and I am senior at the Pennsylvania College > of Technology in Williamsport Pennsylvania. I am enrolled in the Bachelor > of Aviation Maintenance with the first two years concentrating on the A&P > License and the last two on Avionics. As a requirement to graduate we > have to do an intensive senior project. For my project I am designing and > electrical system install in RV-7/7A. The homebuilder is currently > desiding on whether to go with Figure Z-12 or Z-13. I was just wondering > if those diagrams are just basic idea or if the wires are already set at > the right size? Electrical system architecture for light aircraft has not materially changed since the C-140 and C-170 got their first generators and batteries installed in the late 40s. The only real "bump up" in electrical system capabilities came in the late 60s when generators were replaced with alternators and the avionics master switch and bus were added for the wrong reasons. The Z-figures were crafted to offer some choices for system architecture allowing a builder to optimize performance, minimize parts count, and craft simple, failure tolerant operation tailored to an airplane's mission. NONE of the wire sizes, breaker/fuse sizes, or part numbers of components should be construed as recommended for any particular design. I would begin the design for a new aircraft by conducting a load analysis. There is a blank form you can download at: http://www.aeroelectric.com/articles/LoadAnalysis.pdf . . . one page for each bus of your selected architecture. List every electro-whizzie that draws power from the system and deduce its requirements under all the flight conditions noted across the top of the form. This exercise will help you size wires, circuit protection, batteries and alternators. > I thank you for your time and look forward to talking to you in the > future about this if possible. Please join us on the AeroElectric-List which is described at: http://aeroelectric.com/consulting.html This service is free and may be joined or abandoned at any time. Participation on this list will put you in contact with many capable builders/designers who share your interests. I would encourage you to pass this invitation along to your fellow students as well. As you look forward to your own career, please know that the best way to advance the state of your own art is to TEACH IT. The AeroElectric-List is a good place to acquire those skills by taking advantage of all that folks on the List are eager and willing to share. As your personal knowledge and skills grow, you will have much to offer others. When we take the time to share our particular stock of simple ideas and discuss the ways in which those ideas can be assembled into practical inventions, we ALL become teachers in the finest sense of the word. Bob . . . ________________________________________________________________________________
From: "earl_schroeder(at)juno.com" <earl_schroeder(at)juno.com>
Date: Jan 22, 2005
Subject: Re: Battery failure -- lessons and questions on dbm
ail-mx1 In an attempt to squeeze out more life from an old car, I installed an 'aircraft approved master relay' which completely disconnects the battery as it does in aircraft. It solved the very intermittent battery draining situation which I was unable to find. A 'hidden' master switch also serves as an 'immobilizer' although if someone wants this old car... Now my digital clock serves as a time-in-route. Earl -- KITFOXZ(at)aol.com wrote: In a message dated 1/22/2005 5:38:12 A.M. Eastern Standard Time, frankv(at)infogen.net.nz writes: LESSONS: 1. When your battery suggests that it is about to die, take heed! 2. Somehow, a bad battery can prevent a parallel good battery from working! This may be especially relevant for people installing dual batteries in their aircraft -- if you can't isolate a bad battery, it may prevent starting (or even take down the electrical system???) even if you have a good battery (or perhaps even a running alternator???) alongside. Frank Hello Frank, Your lesson # 1 is so very true! This is one reason that Bob always preaches about replacing aircraft batteries on a regular interval. The battery is the most unpredictable component in your aircraft, and yet the most depended upon. An old battery can have a shorted cell, thus reducing the battery's voltage to 10 volts. A jumper battery connected in parallel across this bad 10 volt battery will often be unable to boost the system voltage enough to start your engine. This is why it is a good idea to remove the battery in question from the circuit, if a jump fails to get you going, and replace it with a known good battery. An old battery with a shorted cell will receive full charge current from the charging system too as the voltage regulator pushes tons of current into this bad battery trying to restore its voltage to 13.8. The excess charge current will destroy the other cells in a short time. I have never liked using an "immobilizer" type of device in any of my cars for fear that the thing would fail to "make" my starting circuit on a cold and rainy night. The shops that install them often use any number of poor connection practices as they install these bottom dollar devices. I prefer to not have my starting circuit compromised in any way. A simple noise maker alarm system is my choice. If the thief defeats the alarm or drives off with it screaming, I say let it be. Any electronic theft deterrent is just that in my opinion, a deterrent. The average thief is dumb and in a hurry for an easy victim. Sure there are the pros out there working for chop shops and those few guys will know how to start your car no matter what you have installed to foil them. John P. Marzluf Columbus, Ohio Kitfox Outback (out back in the garage) ________________________________________________________________________________
Date: Jan 22, 2005
From: jerb <ulflyer(at)verizon.net>
Subject: Re: Rotary Switch- solution found
Question - is this switch, switching AC or DV voltages - switches rated for AC normally will only handle a fraction of their current rating when operated in a DC application. It has to do with the type of contacts used in each switch, DC switches cost more to make because of the material that has to be used to reduce arcing when contacts break and resist welding. AC switches take advantage of the zero point crossing of the AC swine wave to reducing arching effect when contact break thus allow the use of lower cost materials for the contacts. jerb > > >Just to say thank you to Leo Corbalis, Rob Prior, and Sigmo for their leads >and suggestions to a replacement of a 25A, 120VAC rotary selector switch. >None of the sources had anything of a high enough capacity, and as a total >greenhorn in electrical or electronic matters, I hesitated going the >relay/contacter route. > >Then my better half came up with a solution after she examined the broken >switch, and that was to use parts of a sheet of Lexan I happen to have >laying around to replace the broken face of the switch. A full day later, >and voila, its repaired and working! Now we will survive the early stages >of the 37th ice age this year. > >Many thanks to the List and the rapid responses it created to our dilemma. > >August > > ________________________________________________________________________________
Date: Jan 22, 2005
From: Robert McCallum <robert.mccallum2(at)sympatico.ca>
Subject: Re: Battery failure -- lessons and questions
on dbmail-mx1 Frank & Dorothy wrote: > >Hi, > >Thought you guys might benefit from my experience today with my car >battery >I recently installed an engine immobiliser after my car disappeared >overnight a couple of times > > Possibly unrelated. > I got a ride to the >nearest gas station, bought a battery (at an exorbitant price) and >borrowed a couple of spanners, and got back to the airfield and replaced >the battery. > > Re-attaching a couple of connections in the process. >Somewhat to my surprise, everything suddenly worked properly! > > Not necessarily surprising. >As I see it now, when the starter motor isn't turning, its coils have >less impedance/resistance than the rest of the circuitry in the car. >Hence, turning the key to 'start' would drop the voltage across the >warning lights so that they went out. But the battery couldn't provide >enough oomph to turn the starter motor, so from the battery's point of >view there was more or less a short circuit. > Very true. Almost always happens with a "dead" battery. > I'm thinking that probably >one (or more) of the battery's cells has died, so the battery couldn't >provide 12.5V, and some reduced amount of current. (I kept the bad >battery, and will investigate it with voltmeter, etc tomorrow) > > Possibly but not necessarily true. Remember those connections you renewed when you changed batteries? An extremely high resistant connection will display exactly the symptoms you describe. I can't count the number of times that I have encountered people with non starting cars with exactly the symptoms you describe whom I've been able to get started by simply disconnecting the battery cables, cleaning the connections and re-attaching them. Instant cure. Corrosion on the terminals of neglected batteries condemns many perfectly good batteries to the scrap heap. Part of battery maintenance is keeping the terminals clean, especially here in the "Great White North" where salt used on the roads in winter corrodes connections very rapidly. >I still don't see why adding more oomph via external battery and jumper >leads didn't get the car started. I guess that somehow the dead cell in >the bad battery was providing some kind of low-resistance path for the >juice from the good battery to flow through, instead of through the >starter motor??? But there was no noticeable heating of the jumper >leads, or loading down of the running car which I'd expect in that >situation. Also, I'd expect (but didn't see) sparks when I attached the >last jumper leads. > > These comments, (no sparks, no heating of the leads, no loading of the running car etc.) usually indicates a poorly connected cable or a cable connected to a corroded battery terminal displaying the above mentioned high resistance. "Most" battery cables which the average person has are totally useless. The average hardware/automotive store cables are of MUCH too small a gauge. A useful jumper cable set should be at least #2 gauge copper wire or heavier with solid copper clamps attached to brightly cleaned connections on both the booster and boosted cars. (vehicles) The "cheap" cables properly connected WILL heat up. This heat is energy not available for starting. No heat and /or no spark and no loading of the booster car means no connection, no current flow hence no boost. >Another question that I'm wondering about: How can putting jumper leads >on a car blow its computer (as I was warned about today)? Surely, from >the computer's point of view, it can't tell whether the flow of >electricity its receiving is coming from the car's own battery, an >external battery, or some combination of both? If 'surges of >electricity' are the culprit as someone contended today, then surely >disconnecting a near-dead battery and connecting a new fully-charged >battery is worse than jumpering the full battery across the near-dead >one? And what about the voltage transients when the alternator starts >up? Is this "putting jumper leads on a car blow its computer" just a myth? > > Generally happens if the boosted car battery is "dead" or disconnected due to bad connections (see above) and you get the cables connected backwards thus powering the computer with reverse polarity. Yes, this can "blow" the computer. Properly connected cables will not cause a problem just as your analysis suggests. >BobN, I'd appreciate it if you would satisy my curiosity over the >physics of what happened today. > > Your turn Bob. >LESSONS: >1. When your battery suggests that it is about to die, take heed! > > Good advice ! > <>2. Somehow, a bad battery can prevent a parallel good battery from > working! This may be especially relevant for people installing dual > batteries in their aircraft -- if you can't isolate a bad battery, it > may prevent starting (or even take down the electrical system???) even > if you have a good battery (or perhaps even a running > alternator???)alongside. Not usually, but, I suppose, sometimes possible. > <>Frank Bob McC ________________________________________________________________________________
From: "Mike Holland" <hollandm(at)pacbell.net>
Subject: Re: Z13a Pre-flight alt test procedure?
Date: Jan 22, 2005
Does your alternator have a built in regulator. Are you wired per Z-24? Yes (Vans 60amp) and Yes. IF NOT . . . then there's nothing at risk for turning the main alternator OFF and aux alternator ON during runup to check your ignition system(s). If you have Z-24 and internally regulated alternator, turn the main alternator OFF and aux alternator ON at engine idle before runup . . . after run up and at engine idle, turn aux alternator OFF and main alternator back ON. Don't concern yourself with voltage readings while aux alternator is ON . . . just not that the current output comes up. You might want to consider running BOTH alternator leads through ONE hall-effect sensor. Since the alternators are tested/used independently from each other, the one current sensor can be used to monitor functionality of both alternators. Would have done that had the b-leads been in some proximity. The main alternator is connected to the Z24 relay on the engine side, lower right, below the battery case and the Aux alternator is high and it's lead goes through the firewall to the regulator mounted inside. I'm using AmpLoc sensors for both so it will interesting to see how easily they are to calibrate. There wired to the Grand Rapid EIS using 2 of the available Aux inputs. 4.8 volts supplied. I won't be concerned about accuracy so much as repeatability since i think if it more as a benchmark and measure of day to day performance. Thanks ________________________________________________________________________________
From: "Paul Messinger" <paulm(at)olypen.com>
Subject: turning off an internally regulated alternator
Date: Jan 22, 2005
> then there's nothing at risk for turning > the main alternator OFF and aux alternator ON during runup to > check your ignition system(s). ALL the Jap internally regulated alternators INCL ND (that I have looked at and that is quite a few but no where all types and ND alone has several different designs) cannot be turned off once turned on and running. Toggle the alt ON OFF connection all you want but the internal regulator is LATCHED on. IS vans ND different?? Its possible to disconnect the "B" lead using the CB but that is disconnecting not turning off the alternator. Paul ________________________________________________________________________________
From: "Paul Messinger" <paulm(at)olypen.com>
Subject: Re: Battery failure -- lessons and questions
Date: Jan 22, 2005
Another thing to consider. There is a ground jumper from the engine block to the frame. I had this come off and got either (1) no starting or (2) the lights going out (3) or it worked just fine. With the jumper missing your ground path is thru the wheel bearings etc which are a variable resistor. In any event fixing the ground jumper remover ALL the above problems for me. Paul ----- Original Message ----- From: "Robert McCallum" <robert.mccallum2(at)sympatico.ca> Subject: Re: AeroElectric-List: Battery failure -- lessons and questions on dbmail-mx1 > > Frank & Dorothy wrote: > > > > >Hi, > > > >Thought you guys might benefit from my experience today with my car > >battery > >I recently installed an engine immobiliser after my car disappeared > >overnight a couple of times > > > > > Possibly unrelated. > > > I got a ride to the > >nearest gas station, bought a battery (at an exorbitant price) and > >borrowed a couple of spanners, and got back to the airfield and replaced > >the battery. > > > > > Re-attaching a couple of connections in the process. > > >Somewhat to my surprise, everything suddenly worked properly! > > > > > Not necessarily surprising. > > >As I see it now, when the starter motor isn't turning, its coils have > >less impedance/resistance than the rest of the circuitry in the car. > >Hence, turning the key to 'start' would drop the voltage across the > >warning lights so that they went out. But the battery couldn't provide > >enough oomph to turn the starter motor, so from the battery's point of > >view there was more or less a short circuit. > > > Very true. Almost always happens with a "dead" battery. > > > I'm thinking that probably > >one (or more) of the battery's cells has died, so the battery couldn't > >provide 12.5V, and some reduced amount of current. (I kept the bad > >battery, and will investigate it with voltmeter, etc tomorrow) > > > > > Possibly but not necessarily true. Remember those connections you > renewed when you changed batteries? An extremely high resistant > connection will display exactly the symptoms you describe. I can't count > the number of times that I have encountered people with non starting > cars with exactly the symptoms you describe whom I've been able to get > started by simply disconnecting the battery cables, cleaning the > connections and re-attaching them. Instant cure. Corrosion on the > terminals of neglected batteries condemns many perfectly good batteries > to the scrap heap. Part of battery maintenance is keeping the terminals > clean, especially here in the "Great White North" where salt used on the > roads in winter corrodes connections very rapidly. > > >I still don't see why adding more oomph via external battery and jumper > >leads didn't get the car started. I guess that somehow the dead cell in > >the bad battery was providing some kind of low-resistance path for the > >juice from the good battery to flow through, instead of through the > >starter motor??? But there was no noticeable heating of the jumper > >leads, or loading down of the running car which I'd expect in that > >situation. Also, I'd expect (but didn't see) sparks when I attached the > >last jumper leads. > > > > > These comments, (no sparks, no heating of the leads, no loading of the > running car etc.) usually indicates a poorly connected cable or a cable > connected to a corroded battery terminal displaying the above mentioned > high resistance. "Most" battery cables which the average person has are > totally useless. The average hardware/automotive store cables are of > MUCH too small a gauge. A useful jumper cable set should be at least #2 > gauge copper wire or heavier with solid copper clamps attached to > brightly cleaned connections on both the booster and boosted cars. > (vehicles) The "cheap" cables properly connected WILL heat up. This heat > is energy not available for starting. No heat and /or no spark and no > loading of the booster car means no connection, no current flow hence no > boost. > > >Another question that I'm wondering about: How can putting jumper leads > >on a car blow its computer (as I was warned about today)? Surely, from > >the computer's point of view, it can't tell whether the flow of > >electricity its receiving is coming from the car's own battery, an > >external battery, or some combination of both? If 'surges of > >electricity' are the culprit as someone contended today, then surely > >disconnecting a near-dead battery and connecting a new fully-charged > >battery is worse than jumpering the full battery across the near-dead > >one? And what about the voltage transients when the alternator starts > >up? Is this "putting jumper leads on a car blow its computer" just a myth? > > > > > Generally happens if the boosted car battery is "dead" or disconnected > due to bad connections (see above) and you get the cables connected > backwards thus powering the computer with reverse polarity. Yes, this > can "blow" the computer. Properly connected cables will not cause a > problem just as your analysis suggests. > > >BobN, I'd appreciate it if you would satisy my curiosity over the > >physics of what happened today. > > > > > Your turn Bob. > > >LESSONS: > >1. When your battery suggests that it is about to die, take heed! > > > > > Good advice ! > > > <>2. Somehow, a bad battery can prevent a parallel good battery from > > working! This may be especially relevant for people installing dual > > batteries in their aircraft -- if you can't isolate a bad battery, it > > may prevent starting (or even take down the electrical system???) even > > if you have a good battery (or perhaps even a running > > alternator???)alongside. > > Not usually, but, I suppose, sometimes possible. > > > <>Frank > > > Bob McC > > ________________________________________________________________________________
From: "Alex Peterson" <alexpeterson(at)earthlink.net>
Subject: turning off an internally regulated alternator
Date: Jan 22, 2005
> ALL the Jap internally regulated alternators INCL ND (that I > have looked at and that is quite a few but no where all types > and ND alone has several different designs) cannot be turned > off once turned on and running. > > Toggle the alt ON OFF connection all you want but the > internal regulator is LATCHED on. > > IS vans ND different?? Paul, I have an internally regulated ND 40amp alternator (Niagara Air Parts) which came with my Aerosport engine. The above statement is not true in my case. My master switch is a three position setup, when the engine is running and I turn off the alternator (which disconnects the 5 amp supply to the alternator), the bus voltage drops to battery voltage. Turn it on, 14 volts, off 12, etc.. Alex Peterson RV6-A 569 hours Maple Grove, MN http://www.home.earthlink.net/~alexpeterson/ ________________________________________________________________________________
From: "Paul Messinger" <paulm(at)olypen.com>
Subject: Re: turning off an internally regulated alternator
Date: Jan 22, 2005
Thanks that clears that up. I wonder is your a rebuilt unit or OEM original as the internal regulators might be wired differently. ALL my investigations were on alternators off autos and none from rebuilders. Paul ----- Original Message ----- From: "Alex Peterson" <alexpeterson(at)earthlink.net> Subject: RE: AeroElectric-List: turning off an internally regulated alternator > > > ALL the Jap internally regulated alternators INCL ND (that I > > have looked at and that is quite a few but no where all types > > and ND alone has several different designs) cannot be turned > > off once turned on and running. > > > > Toggle the alt ON OFF connection all you want but the > > internal regulator is LATCHED on. > > > > IS vans ND different?? > > Paul, > > I have an internally regulated ND 40amp alternator (Niagara Air Parts) which > came with my Aerosport engine. The above statement is not true in my case. > My master switch is a three position setup, when the engine is running and I > turn off the alternator (which disconnects the 5 amp supply to the > alternator), the bus voltage drops to battery voltage. Turn it on, 14 > volts, off 12, etc.. > > Alex Peterson > RV6-A 569 hours > Maple Grove, MN > > http://www.home.earthlink.net/~alexpeterson/ > > ________________________________________________________________________________
From: "Ed Anderson" <eanderson(at)carolina.rr.com>
Subject: Re: turning off an internally regulated alternator
Date: Jan 22, 2005
I originally thought my auto alternator was controllable by the voltage to its field coil. I even convinced myself of this by pulling the 5 amp field coil circuit breaker and starting the engine - sure enough only battery busy voltage. I then pushed in the circuit breaker and sure enough 14.2 volts from the alternator. I then again pulled the alternator field coil circuit breaker and Whoa! it stated at 14.2 volts. A little research on alternators revealed the fact that once the alternator is producing voltage it no longer needs external voltage to the field coil (apparently its provided internally). So once this initial external "boot strap" voltage is provided and the alternator starts producing - the external voltage is no longer required and the alternator can not be disabled by removing it (at least for my alternator and most auto alternators with internal regulation). Your mileage may vary Ed Anderson RV-6A N494BW Matthew, NC ----- Original Message ----- From: "Alex Peterson" <alexpeterson(at)earthlink.net> Subject: RE: AeroElectric-List: turning off an internally regulated alternator > > > ALL the Jap internally regulated alternators INCL ND (that I > > have looked at and that is quite a few but no where all types > > and ND alone has several different designs) cannot be turned > > off once turned on and running. > > > > Toggle the alt ON OFF connection all you want but the > > internal regulator is LATCHED on. > > > > IS vans ND different?? > > Paul, > > I have an internally regulated ND 40amp alternator (Niagara Air Parts) which > came with my Aerosport engine. The above statement is not true in my case. > My master switch is a three position setup, when the engine is running and I > turn off the alternator (which disconnects the 5 amp supply to the > alternator), the bus voltage drops to battery voltage. Turn it on, 14 > volts, off 12, etc.. > > Alex Peterson > RV6-A 569 hours > Maple Grove, MN > > http://www.home.earthlink.net/~alexpeterson/ > > ________________________________________________________________________________
From: "Vincent Welch" <welchvincent(at)hotmail.com>
Subject: Re: Load dump comments
Date: Jan 22, 2005
Paul, What wattage rating would the 1/2 ohm resistor require? Vince >From: "Paul Messinger" <paulm(at)olypen.com> >Reply-To: aeroelectric-list(at)matronics.com >To: >Subject: Re: AeroElectric-List: Re: Load dump comments >Date: Sat, 8 Jan 2005 12:59:16 -0800 > > > >Its wired exactly as Bob shows. > >The power path is thru the CB that powers the relay (in the case of a "B" >lead the contactor) and the crow bar shorts the CB to ground and the 400 >amps is thru the wiring and thru the CB and OVP SCR. There is no HI current >thru the field. > >Draw a wire from the load side of the CB to ground (thats the OVP). The >resulting circuit is the battery to the CB to the OVP to ground. The OVP >tripps and its scr shorts the OVP to ground. Net result is the CB is >directly across the battery plus wiring. The modern battery will provide >more than 1000 amps (some closer to 2000 amps) across the CB with very >short >leads. One solution is a 1/8 to 1/2 ohm resistor in the OVP shorting path >to >limit current and still blow the CB. > >I got 730 amps with shorter but realistic leads and the Powersonic 12v18ah >battery that Bob promotes. Far cry from a Gill flooded cell acft battery. > >I tried 3 different popular 5 amp CB brands and all showed at least 50 ms >to >open. (and that is when they are warmed up). After a couple of hours at >rest >the CB can take more than 80MS to trip. Yes they are that slow. > >Paul > >----- Original Message ----- >From: "Kevin Horton" <khorton01(at)rogers.com> >To: >Subject: Re: AeroElectric-List: Re: Load dump comments > > > > > > > I'm interested as to which two items the crowbar was shorting when > > these large currents were measured. I'm assuming this is a different > > application than the crowbar OV protection that Bod espouses, where > > the crowbar shorts out the field circuit, popping a 5A CB. I can't > > imagine how 400 to 700 amps could be generated in the field circuit > > before the 5A CB popped. Are CBs that slow to trip? Or, was this a > > different application of a crowbar? > > > > Kevin Horton > > > > > > > > >The huge current loop during a shorting crowbar event generates a large > > >magnetic field that can magnetize steel and mess up your compass > > >calibration. > > > > > >I got 400 amps with longer that likely wires. When I simulated my >aircraft > > >wiring I got over 700 amps. > > > > > >Measurements were made with calibrated equipment. as well as being > > >repeatable. > > > > > >If this does not bother you, be my guest. > > > > > >Paul > > > > > > > > >> Sure that sounds scary but I'll wait for the report before getting > > >> concerned. With 6 feet of 18awg wire in series with a C/B, an SCR, >and > > >> several connections it may be possible to get a couple of hundred >amps > > >> of instantaneous current flowing but so what? It is drawing down the > > >> voltage which is what we want. > > >> > > >> The interesting thing to me is a nuisance trip. It sounds like it is > > >> possible to ramp up the alternator output during the delay (40 ms?) > > >> waiting for the OV contactor to open. However I haven't seen any >reason > > > > to be concerned about that yet and I will await the report. > > > > > > ________________________________________________________________________________
From: "Paul Messinger" <paulm(at)olypen.com>
Subject: Re: turning off an internally regulated alternator
Date: Jan 22, 2005
Your alternator internal regulator sounds like what I have seen. There is an internal path from the "B" lead that powers the regulator as well as internal regulator logic that "latches" the regulator in the ON condition Clearly different brands and differenced between types of the same brand are out there. Both of the below messages demonstrate this. Can anyone who has a Vans rebuilt ND alternator comment on how that version works with respect to this thread. Paul ----- Original Message ----- From: "Ed Anderson" <eanderson(at)carolina.rr.com> Subject: Re: AeroElectric-List: turning off an internally regulated alternator > > I originally thought my auto alternator was controllable by the voltage to > its field coil. I even convinced myself of this by pulling the 5 amp field > coil circuit breaker and starting the engine - sure enough only battery busy > voltage. I then pushed in the circuit breaker and sure enough 14.2 volts > from the alternator. I then again pulled the alternator field coil circuit > breaker and Whoa! it stated at 14.2 volts. A little research on alternators > revealed the fact that once the alternator is producing voltage it no longer > needs external voltage to the field coil (apparently its provided > internally). So once this initial external "boot strap" voltage is provided > and the alternator starts producing - the external voltage is no longer > required and the alternator can not be disabled by removing it (at least for > my alternator and most auto alternators with internal regulation). Your > mileage may vary > > Ed Anderson > RV-6A N494BW > Matthew, NC > ----- Original Message ----- > From: "Alex Peterson" <alexpeterson(at)earthlink.net> > To: > Subject: RE: AeroElectric-List: turning off an internally regulated > alternator > > > > > > > > ALL the Jap internally regulated alternators INCL ND (that I > > > have looked at and that is quite a few but no where all types > > > and ND alone has several different designs) cannot be turned > > > off once turned on and running. > > > > > > Toggle the alt ON OFF connection all you want but the > > > internal regulator is LATCHED on. > > > > > > IS vans ND different?? > > > > Paul, > > > > I have an internally regulated ND 40amp alternator (Niagara Air Parts) > which > > came with my Aerosport engine. The above statement is not true in my > case. > > My master switch is a three position setup, when the engine is running and > I > > turn off the alternator (which disconnects the 5 amp supply to the > > alternator), the bus voltage drops to battery voltage. Turn it on, 14 > > volts, off 12, etc.. > > > > Alex Peterson > > RV6-A 569 hours > > Maple Grove, MN > > > > http://www.home.earthlink.net/~alexpeterson/ > > > > > > ________________________________________________________________________________
From: "Alex Peterson" <alexpeterson(at)earthlink.net>
Subject: turning off an internally regulated alternator
Date: Jan 22, 2005
Mine is (was) new five years ago. Call to confirm, but I seem to recall that Aerosport Power got them from Niagara Air Parts. See http://www.niagaraairparts.com/ 3/4's down the page. Alex Peterson > --> > > Thanks that clears that up. I wonder is your a rebuilt unit > or OEM original as the internal regulators might be wired > differently. ALL my investigations were on alternators off > autos and none from rebuilders. > > Paul > > ----- Original Message ----- > From: "Alex Peterson" <alexpeterson(at)earthlink.net> > To: > Subject: RE: AeroElectric-List: turning off an internally > regulated alternator > > > > > > > > ALL the Jap internally regulated alternators INCL ND (that I have > > > looked at and that is quite a few but no where all types and ND > > > alone has several different designs) cannot be turned off once > > > turned on and running. > > > > > > Toggle the alt ON OFF connection all you want but the internal > > > regulator is LATCHED on. > > > > > > IS vans ND different?? > > > > Paul, > > > > I have an internally regulated ND 40amp alternator (Niagara > Air Parts) > which > > came with my Aerosport engine. The above statement is not > true in my > case. > > My master switch is a three position setup, when the engine > is running > > and > I > > turn off the alternator (which disconnects the 5 amp supply to the > > alternator), the bus voltage drops to battery voltage. > Turn it on, 14 > > volts, off 12, etc.. > > > > Alex Peterson > > RV6-A 569 hours > > Maple Grove, MN > > > > http://www.home.earthlink.net/~alexpeterson/ > > > > > > > ========= > Matronics Forums. > ========= > http://www.matronics.com/FAQ/AeroElectric-List.htm > ========= > > > > > ________________________________________________________________________________
From: "Vincent Welch" <welchvincent(at)hotmail.com>
Subject: Load Dump Question
Date: Jan 22, 2005
Hey guys, I have been watching this "Battle Of The Titans" with great interest. I have a question from one a bit lower down the food chain:) It has always been my understanding that the purpose of the OV circuit was to protect my avionics from a runaway alternator. The alternator or regulator has already failed and the voltage is climbing. The crowbar opens the circuit to limit prevent damage to my expensive avionics. The alternator/regulator has already failed, its trash, so I open the B-lead under load, I get a load dump event. So what? Why do I care about trying to protect the alternator now? I can understand limiting the crowbar circuit current and adding a resistor sounds like a simple easy solution to that problem. What am I missing here? Please further educate me. Vince ________________________________________________________________________________
From: "Paul Messinger" <paulm(at)olypen.com>
Subject: OVP current limiting
Date: Jan 22, 2005
New subject line above First lets pick a resistance from the following table to suit your comfort. OHM aprox current 0.1 120 amps 0.2 60 amps 0.3 40 amps 0.4 30 amps 0.5 24 amps Any of the above resistance values will blow most CB's in about the same time. Any value is better than a dead short plus wiring drops. (I get 400-700+ amps depending on wiring length etc and battery used with no series resistor.) I would recommend 0.2 to 0.4 ohms as reasonable compromise. Around 10 times the CB rating ends up with the fastest possible trip time. Thus 50 amps is more than enough for a 5 amp CB. Wattage is not important but the resistors ability pass the current pulse is the driving parameter. So a 1/2 watt might be OK, I would use a one watt to be sure. Most any brand or type will work fine. If you made your OVP from Bob's plans it can be added to the circuit, or simply added in line externally. I will have more comments on the Crowbar approach and how its different from the classic short and blow a fuse or CB protecting avionics etc. Not quite the same issues and concerns. Paul PS Thanks for asking ----- Original Message ----- From: "Vincent Welch" <welchvincent(at)hotmail.com> Subject: Re: AeroElectric-List: Re: Load dump comments > > Paul, > > What wattage rating would the 1/2 ohm resistor require? > > Vince > > >From: "Paul Messinger" <paulm(at)olypen.com> > >Reply-To: aeroelectric-list(at)matronics.com > >To: > >Subject: Re: AeroElectric-List: Re: Load dump comments > >Date: Sat, 8 Jan 2005 12:59:16 -0800 > > > > > > > >Its wired exactly as Bob shows. > > > >The power path is thru the CB that powers the relay (in the case of a "B" > >lead the contactor) and the crow bar shorts the CB to ground and the 400 > >amps is thru the wiring and thru the CB and OVP SCR. There is no HI current > >thru the field. > > > >Draw a wire from the load side of the CB to ground (thats the OVP). The > >resulting circuit is the battery to the CB to the OVP to ground. The OVP > >tripps and its scr shorts the OVP to ground. Net result is the CB is > >directly across the battery plus wiring. The modern battery will provide > >more than 1000 amps (some closer to 2000 amps) across the CB with very > >short > >leads. One solution is a 1/8 to 1/2 ohm resistor in the OVP shorting path > >to > >limit current and still blow the CB. > > > >I got 730 amps with shorter but realistic leads and the Powersonic 12v18ah > >battery that Bob promotes. Far cry from a Gill flooded cell acft battery. > > > >I tried 3 different popular 5 amp CB brands and all showed at least 50 ms > >to > >open. (and that is when they are warmed up). After a couple of hours at > >rest > >the CB can take more than 80MS to trip. Yes they are that slow. > > > >Paul > > > >----- Original Message ----- > >From: "Kevin Horton" <khorton01(at)rogers.com> > >To: > >Subject: Re: AeroElectric-List: Re: Load dump comments > > > > > > > > > > > > I'm interested as to which two items the crowbar was shorting when > > > these large currents were measured. I'm assuming this is a different > > > application than the crowbar OV protection that Bod espouses, where > > > the crowbar shorts out the field circuit, popping a 5A CB. I can't > > > imagine how 400 to 700 amps could be generated in the field circuit > > > before the 5A CB popped. Are CBs that slow to trip? Or, was this a > > > different application of a crowbar? > > > > > > Kevin Horton > > > > > > > > > > > > >The huge current loop during a shorting crowbar event generates a large > > > >magnetic field that can magnetize steel and mess up your compass > > > >calibration. > > > > > > > >I got 400 amps with longer that likely wires. When I simulated my > >aircraft > > > >wiring I got over 700 amps. > > > > > > > >Measurements were made with calibrated equipment. as well as being > > > >repeatable. > > > > > > > >If this does not bother you, be my guest. > > > > > > > >Paul > > > > > > > > > > > >> Sure that sounds scary but I'll wait for the report before getting > > > >> concerned. With 6 feet of 18awg wire in series with a C/B, an SCR, > >and > > > >> several connections it may be possible to get a couple of hundred > >amps > > > >> of instantaneous current flowing but so what? It is drawing down the > > > >> voltage which is what we want. > > > >> > > > >> The interesting thing to me is a nuisance trip. It sounds like it is > > > >> possible to ramp up the alternator output during the delay (40 ms?) > > > >> waiting for the OV contactor to open. However I haven't seen any > >reason > > > > > to be concerned about that yet and I will await the report. > > > > > > > > > > > > ________________________________________________________________________________
From: "Mark Banus" <mbanus(at)hotmail.com>
Subject: Pilot stick grip priority options rev B
Date: Jan 22, 2005
Bob, I am about to start building your circuit for pilot priority. I intend to use 1N4001 diodes and a T9AP5D52-12 relay. Is there a more appropriate relay for this application? Thanks Mark Banus Glasair S II S FT ________________________________________________________________________________
From: "Paul Messinger" <paulm(at)olypen.com>
Subject: Re: turning off an internally regulated alternator
Date: Jan 22, 2005
Thanks I will try to get more info monday when they are open. Paul ----- Original Message ----- From: "Alex Peterson" <alexpeterson(at)earthlink.net> Subject: RE: AeroElectric-List: turning off an internally regulated alternator > > > Mine is (was) new five years ago. Call to confirm, but I seem to recall > that Aerosport Power got them from Niagara Air Parts. See > http://www.niagaraairparts.com/ 3/4's down the page. > > Alex Peterson > > > --> > > > > Thanks that clears that up. I wonder is your a rebuilt unit > > or OEM original as the internal regulators might be wired > > differently. ALL my investigations were on alternators off > > autos and none from rebuilders. > > > > Paul > > > > ----- Original Message ----- > > From: "Alex Peterson" <alexpeterson(at)earthlink.net> > > To: > > Subject: RE: AeroElectric-List: turning off an internally > > regulated alternator > > > > > > > > > > > > > ALL the Jap internally regulated alternators INCL ND (that I have > > > > looked at and that is quite a few but no where all types and ND > > > > alone has several different designs) cannot be turned off once > > > > turned on and running. > > > > > > > > Toggle the alt ON OFF connection all you want but the internal > > > > regulator is LATCHED on. > > > > > > > > IS vans ND different?? > > > > > > Paul, > > > > > > I have an internally regulated ND 40amp alternator (Niagara > > Air Parts) > > which > > > came with my Aerosport engine. The above statement is not > > true in my > > case. > > > My master switch is a three position setup, when the engine > > is running > > > and > > I > > > turn off the alternator (which disconnects the 5 amp supply to the > > > alternator), the bus voltage drops to battery voltage. > > Turn it on, 14 > > > volts, off 12, etc.. > > > > > > Alex Peterson > > > RV6-A 569 hours > > > Maple Grove, MN > > > > > > http://www.home.earthlink.net/~alexpeterson/ > > > > > > > > > > > > ========= > > Matronics Forums. > > ========= > > http://www.matronics.com/FAQ/AeroElectric-List.htm > > ========= > > > > > > > > > > > > ________________________________________________________________________________
From: "Paul Messinger" <paulm(at)olypen.com>
Subject: Re: Load Dump Question
Date: Jan 22, 2005
As I recall the original start of this thread was early last year when there were failures of Van's rebuilt alternators. Bob and others questioned the quality of the rebuilt regulator in the Van's alternator. Personally I have never seen any real proof of what was the true cause. I have real trouble believing Van would sell substandard alternators. ALL standard alternator internal regulators are protected against worst case load dump. Any way You are correct that in the case of a real alternator regulator HI voltage failure, the only solution is to cut the "B" lead and "so what" if that causes an isolated load dump that the alternator cannot take. However if the alternator is working fine and the battery is disconnected the resulting load dump is distributed to the bus and can cause harm depending on what is on the bus and how big the load dump is. There are a couple of solutions to this. First a transorb big enough to clamp the load dump hi voltage. This has nothing directly to do with any OVP device present. However Bob's crow bar OVP will trigger with the above load dump and this results in the hi current during its operation that some of us object to. A simple addition of a small value series resistor fixes that. If the load dump is a result of the "B" lead opening the load dump issue is contained to the alternator where you may or may not damage the alternator internal regulator. A transorb on the alternator side of the "B" lead contactor will protect the alternator if the regulator is not up to the task. This is a second transorb as one needs to be on the Bus side also. If the load dump is a result of disconnecting a charging battery the load dump is delivered to the aircraft bus and potential damage can result to your avionics. Its likely the OVP will trip but not in time in all cases to prevent a short hi voltage pulse on the BUS. The OVP takes some time to start clamping (5-10MS?) and much longer (50-100ms) to disconnect the alternator thru the "B" lead contactor. Even 5 ms is long with a 60V or higher pulse on BUS. So some of us feel the need for the "Transorb" to keep the BUS voltages clamped while the OVP can act. The transorb acts not in 5 MS but in 1/2 pico second 10,000+ times faster and faster than any damage can start. If the failure is a failed hi voltage alternator the transorb clamps the voltage while the OVP acts. Both arte needed in the safest system. If this does not answer your concerns ask more as everyone benefits from such a "conversation" Paul ----- Original Message ----- From: "Vincent Welch" <welchvincent(at)hotmail.com> Subject: AeroElectric-List: Load Dump Question > > Hey guys, I have been watching this "Battle Of The Titans" with great > interest. I have a question from one a bit lower down the food chain:) > > It has always been my understanding that the purpose of the OV circuit was > to protect my avionics from a runaway alternator. The alternator or > regulator has already failed and the voltage is climbing. The crowbar opens > the circuit to limit prevent damage to my expensive avionics. The > alternator/regulator has already failed, its trash, so I open the B-lead > under load, I get a load dump event. So what? Why do I care about trying > to protect the alternator now? > > I can understand limiting the crowbar circuit current and adding a resistor > sounds like a simple easy solution to that problem. > > What am I missing here? Please further educate me. > > Vince > > ________________________________________________________________________________
Date: Jan 22, 2005
From: "Dan O'Brien" <danobrien(at)cox.net>
Subject: Garmin/Microencoder wiring question
I am wiring the serial connection from my Microencoder to my Garmin 430. The Garmin documentation shows a shielded twisted pair with the shield grounded a both ends and the Attitude Common pin (part of the twisted pair) connected to the shield at the Garmin and connected to the Power Ground wire at the encoder. Question: Does it matter whether the Attitude Common pin is grounded at the Garmin given that it is also grounded through the encoder? I'm asking because I already wired the Garmin end without connecting it to the shield. I can always rip the pin out and do it over, but would prefer not to :). ________________________________________________________________________________
Date: Jan 22, 2005
From: "Dan O'Brien" <danobrien(at)cox.net>
Subject: General radio grounding question
My Garmin 430 and UPS SL30 both have case ground studs. Question: Do the ground studs run to Power Ground through the radios, or are they something completely different? I'm puzzling over this because my Garmin came with a partial harness that connects shields to the case, which is simply depicted with a ground symbol in the installation manual. I'm assuming that this means that the case is connected to the Aircraft ground through the Power Ground pin in the harness. If this were not the case, how would I know from the ground symbol depicted in the manual that the case ground is something different than the aircraft power ground? There is no mention in the manual that the shields should be grounded to the case INSTEAD OF the aircraft power ground. If I sound a bit confused, it's because I AM ! ________________________________________________________________________________
From: "Wayne Sweet" <w_sweet(at)comcast.net>
Subject: Re: Garmin/Microencoder wiring question
Date: Jan 22, 2005
I just finished wiring my 430 with encoder, but the input was the 11 pin (gray code, I think it's referred to as). The Garmin wiring diagrams are wrong in this and one other in respect to the grounding at both ends of the shields. Do not ground both ends of the shields or the least that will (could) cause a ground plane loop. I called, and asked Garmin tech guys at the AOPA convention about the shield grounding at both ends for the GI-106A obs, and at first I received somewhat blank stares. Then finally got a definitive NO, do not ground shields at both ends. I know for a fact, that grounding the shields between the 430 and the audio panel (in my case, PS Engineering's PMA6000) will cause havoc with the com output. On mine the altitude common is simply ground. This was the answer I finally got from Garmin; the TransCal (my encoder) people didn't know and in fact ask me to call them back when I found the answer. If the encoder pin-out has a Altitude Common, then of course use it. BTW, I would NEVER do that sort of wiring job myself (GNS430, GI-106A, PMA6000, Navaid Device, Terra NAV/COM, Terra Marker Beacon). After having done it, I learned of FastStack by Approach Systems. Good luck; Oh I learned that the ungrounded end of the shields should be heat shrink wrapped to prevent the shield from touching any structure, other wires, thereby causing a ground plane loop. Wayne ----- Original Message ----- From: "Dan O'Brien" <danobrien(at)cox.net> Subject: AeroElectric-List: Garmin/Microencoder wiring question > > I am wiring the serial connection from my Microencoder to my Garmin > 430. The Garmin documentation shows a shielded twisted pair with the > shield grounded a both ends and the Attitude Common pin (part of the > twisted pair) connected to the shield at the Garmin and connected to the > Power Ground wire at the encoder. Question: Does it matter whether the > Attitude Common pin is grounded at the Garmin given that it is also > grounded through the encoder? I'm asking because I already wired the > Garmin end without connecting it to the shield. I can always rip the pin > out and do it over, but would prefer not to :). > > > Try www.SPAMfighter.com for free now! ________________________________________________________________________________
From: "Wayne Sweet" <w_sweet(at)comcast.net>
Subject: Re: General radio grounding question
Date: Jan 22, 2005
The assumption is (by Garmin) is the 430 tray is connected to the airframe through mounting screws, and the ground terminals (I found the purpose of those at AOPA convention) is connected to the tray, and the tray to the airframe. At least that's the way mine is and it works. Wayne ----- Original Message ----- From: "Dan O'Brien" <danobrien(at)cox.net> Subject: AeroElectric-List: General radio grounding question > > My Garmin 430 and UPS SL30 both have case ground studs. Question: Do the > ground studs run to Power Ground through the radios, or are they something > completely different? > > I'm puzzling over this because my Garmin came with a partial harness that > connects shields to the case, which is simply depicted with a ground > symbol > in the installation manual. I'm assuming that this means that the case is > connected to the Aircraft ground through the Power Ground pin in the > harness. If this were not the case, how would I know from the ground > symbol depicted in the manual that the case ground is something different > than the aircraft power ground? There is no mention in the manual that > the > shields should be grounded to the case INSTEAD OF the aircraft power > ground. > > If I sound a bit confused, it's because I AM ! > > > Try www.SPAMfighter.com for free now! ________________________________________________________________________________
Date: Jan 22, 2005
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: Load Dump Question
> >As I recall the original start of this thread was early last year when there >were failures of Van's rebuilt alternators. Bob and others questioned the >quality of the rebuilt regulator in the Van's alternator. > >Personally I have never seen any real proof of what was the true cause. I >have real trouble believing Van would sell substandard alternators. ALL >standard alternator internal regulators are protected against worst case >load dump. > >Any way You are correct that in the case of a real alternator regulator HI >voltage failure, the only solution is to cut the "B" lead and "so what" if >that causes an isolated load dump that the alternator cannot take. > >However if the alternator is working fine and the battery is disconnected >the resulting load dump is distributed to the bus and can cause harm >depending on what is on the bus and how big the load dump is. > >There are a couple of solutions to this. First a transorb big enough to >clamp the load dump hi voltage. This has nothing directly to do with any OVP >device present. > >However Bob's crow bar OVP will trigger with the above load dump and this >results in the hi current during its operation that some of us object to. A >simple addition of a small value series resistor fixes that. If the battery is off line and the crowbar "trips" there is no high current pulse. The alternator is physically incapable of delivering more than a few percent above rated current. Once the battery is out of the loop, a crowbar trip sinks the relatively low current of the alternator . . . the alternator looses excitation and dies. >If the load dump is a result of the "B" lead opening the load dump issue is >contained to the alternator where you may or may not damage the alternator >internal regulator. A transorb on the alternator side of the "B" lead >contactor will protect the alternator if the regulator is not up to the >task. This is a second transorb as one needs to be on the Bus side also. Why? if load dump energies come from the alternator, one Transorb at the alternator's b-lead terminal should suffice for all cases. >If the load dump is a result of disconnecting a charging battery the load >dump is delivered to the aircraft bus and potential damage can result to >your avionics. Its likely the OVP will trip but not in time in all cases to >prevent a short hi voltage pulse on the BUS. The OVP takes some time to >start clamping (5-10MS?) and much longer (50-100ms) to disconnect the >alternator thru the "B" lead contactor. Even 5 ms is long with a 60V or >higher pulse on BUS. > >So some of us feel the need for the "Transorb" to keep the BUS voltages >clamped while the OVP can act. The transorb acts not in 5 MS but in 1/2 pico >second 10,000+ times faster and faster than any damage can start. > >If the failure is a failed hi voltage alternator the transorb clamps the >voltage while the OVP acts. Both arte needed in the safest system. > >If this does not answer your concerns ask more as everyone benefits from >such a "conversation" Agreed! Bob . . . ________________________________________________________________________________
From: "Vincent Welch" <welchvincent(at)hotmail.com>
Subject: Re: Load Dump Question
Date: Jan 22, 2005
OK, I'm almost with you Paul. If I place a transorb (say, the Whackjack) on the alternator side of the B-Lead contactor, doesn't that clamp the entire line from alternator, through contactor, to the bus? If the battery is taken offline accidently isn't the bus still clamped through that transorb? If the B-Lead contactor opens due to the OVP trip won't the bus voltage be stabilized by the battery? If all of these things are true, why do we need a second transorb on the bus side? If I do need a second transorb on the bus side, is another Whackjack acceptable or should I use something else? If so, what? Vince >From: "Paul Messinger" <paulm(at)olypen.com> >Reply-To: aeroelectric-list(at)matronics.com >To: >Subject: Re: AeroElectric-List: Load Dump Question >Date: Sat, 22 Jan 2005 14:26:53 -0800 > > > >As I recall the original start of this thread was early last year when >there >were failures of Van's rebuilt alternators. Bob and others questioned the >quality of the rebuilt regulator in the Van's alternator. > >Personally I have never seen any real proof of what was the true cause. I >have real trouble believing Van would sell substandard alternators. ALL >standard alternator internal regulators are protected against worst case >load dump. > >Any way You are correct that in the case of a real alternator regulator HI >voltage failure, the only solution is to cut the "B" lead and "so what" if >that causes an isolated load dump that the alternator cannot take. > >However if the alternator is working fine and the battery is disconnected >the resulting load dump is distributed to the bus and can cause harm >depending on what is on the bus and how big the load dump is. > >There are a couple of solutions to this. First a transorb big enough to >clamp the load dump hi voltage. This has nothing directly to do with any >OVP >device present. > >However Bob's crow bar OVP will trigger with the above load dump and this >results in the hi current during its operation that some of us object to. A >simple addition of a small value series resistor fixes that. > >If the load dump is a result of the "B" lead opening the load dump issue is >contained to the alternator where you may or may not damage the alternator >internal regulator. A transorb on the alternator side of the "B" lead >contactor will protect the alternator if the regulator is not up to the >task. This is a second transorb as one needs to be on the Bus side also. > >If the load dump is a result of disconnecting a charging battery the load >dump is delivered to the aircraft bus and potential damage can result to >your avionics. Its likely the OVP will trip but not in time in all cases to >prevent a short hi voltage pulse on the BUS. The OVP takes some time to >start clamping (5-10MS?) and much longer (50-100ms) to disconnect the >alternator thru the "B" lead contactor. Even 5 ms is long with a 60V or >higher pulse on BUS. > >So some of us feel the need for the "Transorb" to keep the BUS voltages >clamped while the OVP can act. The transorb acts not in 5 MS but in 1/2 >pico >second 10,000+ times faster and faster than any damage can start. > >If the failure is a failed hi voltage alternator the transorb clamps the >voltage while the OVP acts. Both arte needed in the safest system. > >If this does not answer your concerns ask more as everyone benefits from >such a "conversation" > >Paul > >----- Original Message ----- >From: "Vincent Welch" <welchvincent(at)hotmail.com> >To: >Subject: AeroElectric-List: Load Dump Question > > > > > > > Hey guys, I have been watching this "Battle Of The Titans" with great > > interest. I have a question from one a bit lower down the food chain:) > > > > It has always been my understanding that the purpose of the OV circuit >was > > to protect my avionics from a runaway alternator. The alternator or > > regulator has already failed and the voltage is climbing. The crowbar >opens > > the circuit to limit prevent damage to my expensive avionics. The > > alternator/regulator has already failed, its trash, so I open the B-lead > > under load, I get a load dump event. So what? Why do I care about >trying > > to protect the alternator now? > > > > I can understand limiting the crowbar circuit current and adding a >resistor > > sounds like a simple easy solution to that problem. > > > > What am I missing here? Please further educate me. > > > > Vince > > > > > > ________________________________________________________________________________
Date: Jan 22, 2005
From: "Dan O'Brien" <danobrien(at)cox.net>
Subject: Re: Garmin/Microencoder wiring question
>The Garmin wiring diagrams are wrong in this and one other in respect >to the grounding at both ends of the >shields. Do not ground both ends of the shields or the least that will >(could) cause a ground plane loop. I called, and asked Garmin tech guys at >the AOPA convention about the shield grounding at both ends for the GI-106A >obs, and at first I received somewhat blank stares. Then finally got a >definitive NO, do not ground shields at both ends. So the manual is incorrect? Well, that leaves me in a lurch, since if the shield is only supposed to be grounded at one end, which end? Guess I'll call Garmin. In the past, they've not been very helpful, as the unit is "supposed to be wired by an avionics supplier." (This is unlike the old UPS, which was great in supporting the experimental market. Of course, USP is now Garmin too.) We'll see. ________________________________________________________________________________
Date: Jan 22, 2005
From: "Dan O'Brien" <danobrien(at)cox.net>
Subject: Re: General Wiring Question
>The assumption is (by Garmin) is the 430 tray is connected to the airframe >through mounting screws, and the ground terminals (I found the purpose of >those at AOPA convention) is connected to the tray, and the tray to the >airframe. At least that's the way mine is and it works. On a composite like my Lancair, the mounting screws will not ground the tray. Is one supposed to run a wire from the ground stud on the radio case to the ground bus? There is no mention of this in either the Garmin 430 or UPS SL30 manuals. ________________________________________________________________________________
From: "Wayne Sweet" <w_sweet(at)comcast.net>
Subject: Re: Garmin/Microencoder wiring question
Date: Jan 22, 2005
Dan, I told them it was an experimental airplane and I was the builder. They willingly answered my questions. Are you calling Garmin or the avionics retail store you bought it from?? I would ground the shields for the encoder wiring at the GND430, on the shield ground connector. Wayne ----- Original Message ----- From: "Dan O'Brien" <danobrien(at)cox.net> Subject: AeroElectric-List: Re: Garmin/Microencoder wiring question > > > >The Garmin wiring diagrams are wrong in this and one other in respect > >to the grounding at both ends of the > >shields. Do not ground both ends of the shields or the least that will > >(could) cause a ground plane loop. I called, and asked Garmin tech guys > >at > >the AOPA convention about the shield grounding at both ends for the > >GI-106A > >obs, and at first I received somewhat blank stares. Then finally got a > >definitive NO, do not ground shields at both ends. > > So the manual is incorrect? Well, that leaves me in a lurch, since if the > shield > is only supposed to be grounded at one end, which end? Guess I'll call > Garmin. > In the past, they've not been very helpful, as the unit is "supposed to be > wired by an avionics supplier." (This is unlike the old UPS, which was > great > in supporting the experimental market. Of course, USP is now Garmin too.) > We'll see. > > > Try www.SPAMfighter.com for free now! ________________________________________________________________________________
From: "Wayne Sweet" <w_sweet(at)comcast.net>
Subject: Re: General Wiring Question
Date: Jan 22, 2005
OK, I may be wrong. The 430 does have a ground wire for both the COM and GPS power supplies (connectors P4002 and P4001). Check with a multimeter (ohms) to see if the ground terminals, that funny looking thing on the back of the tray, Fig F-6 which identifies it as Shield Grounds, and one of the ground wires have continuity when the 430 is plugged in. If not, then I would guess you need to run a ground wire from the tray to you aircraft ground bus. Let us know what you find out. Wayne ----- Original Message ----- From: "Dan O'Brien" <danobrien(at)cox.net> Subject: AeroElectric-List: Re: General Wiring Question > > > >The assumption is (by Garmin) is the 430 tray is connected to the > >airframe > >through mounting screws, and the ground terminals (I found the purpose of > >those at AOPA convention) is connected to the tray, and the tray to the > >airframe. At least that's the way mine is and it works. > > On a composite like my Lancair, the mounting screws will not ground the > tray. > Is one supposed to run a wire from the ground stud > on the radio case to the ground bus? There is no mention of this > in either the Garmin 430 or UPS SL30 manuals. > > > Try www.SPAMfighter.com for free now! ________________________________________________________________________________
Date: Jan 23, 2005
From: "Dan O'Brien" <danobrien(at)cox.net>
Subject: Re: Re: General Wiring Question
>The assumption is (by Garmin) is the 430 tray is connected to the airframe >through mounting screws, and the ground terminals (I found the purpose of >those at AOPA convention) is connected to the tray, and the tray to the >airframe. At least that's the way mine is and it works. >>On a composite like my Lancair, the mounting screws will not ground the tray. >>Is one supposed to run a wire from the ground stud >>on the radio case to the ground bus? There is no mention of this >>in either the Garmin 430 or UPS SL30 manuals. >>>OK, I may be wrong. The 430 does have a ground wire for both the COM and GPS >>>power supplies (connectors P4002 and P4001). Check with a multimeter (ohms) >>>to see if the ground terminals, that funny >>>looking thing on the back of the tray, Fig F-6 which identifies it as Shield >>>Grounds, and one of the ground wires have continuity when the 430 is plugged >>>in. If not, then I would guess you need to run a ground wire from the tray to >>>you aircraft ground bus. Let us know what you find out. Wayne, Thanks for the suggestion. I checked with an ohmmeter with the cables plugged in, and all the grounds --- the Aircraft Power pins on the P4001 and P4002 connectors, along with the case ground stud --- are tied together. Answers my question. Thanks, Dan ________________________________________________________________________________
Date: Jan 23, 2005
From: "William Yamokoski" <yamokosk(at)lakemichigancollege.edu>
Subject: MicroAir Antenna
Hi Folks, I notice that MicroAir is offering a com antenna they recommend for composite aircraft. Supposedly no ground plane required. Does anyone have information on this? I currently have MicroAir 760 and a copper strip dipole antenna in the vertical stabilizer of my GlaStar...looking to try something else. Thanks for any input. Bill Yamokoski, N4970Y 430 hrs on the EggenSoob that fires right up in 10 degree weather ________________________________________________________________________________
From: "Glen Matejcek" <aerobubba(at)earthlink.net>
Subject: Hall effect sensor
Date: Jan 23, 2005
Hi All- A short while ago, someone (Bob, I believe) made the suggestion to run both the main and stby alt B leads through the same Hall effect sensor. Seems like a pretty nifty idea, but something just came to mind. The installation instructions for the SD-8 call for the leads from the SD-8 all the way to the battery to be a twisted pair. How close can the ground wire be to the Hall effect sensor before it starts to influence the sensor vs. the need to maintain the twisted pair for noise suppression? As ever, thanks in advance! Glen Matejcek aerobubba(at)earthlink.net ________________________________________________________________________________
From: "Paul Messinger" <paulm(at)olypen.com>
Subject: Re: Load Dump Question
Date: Jan 23, 2005
----- Original Message ----- From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> Subject: Re: AeroElectric-List: Load Dump Question > > > > >However Bob's crow bar OVP will trigger with the above load dump and this > >results in the hi current during its operation that some of us object to. A > >simple addition of a small value series resistor fixes that. > > If the battery is off line and the crowbar "trips" there is no > high current pulse. The alternator is physically incapable of > delivering more than a few percent above rated current. Once > the battery is out of the loop, a crowbar trip sinks the relatively > low current of the alternator . . . the alternator looses excitation > and dies. Not sure about the alternators ability to exceed the max rated current by only a small amount. The one I tested was rated at 55 amps and at 55 amps the regulator was still far less than 100% duty cycle for full field current. 100% is needed for the true max current which may be far more than rated current in some products. Thus its my opinion that currents up to 100 amps are possible with larger alternators and in any event there is simply no reason to have a product (OVP) that produces currents excessive to the job. We gain nothing in more than 20-30 amps in speed of tripping a 5 amp CB based on my testing of several common types. > > >If the load dump is a result of the "B" lead opening the load dump issue is > >contained to the alternator where you may or may not damage the alternator > >internal regulator. A transorb on the alternator side of the "B" lead > >contactor will protect the alternator if the regulator is not up to the > >task. This is a second transorb as one needs to be on the Bus side also. > > Why? if load dump energies come from the alternator, one Transorb > at the alternator's b-lead terminal should suffice for all cases. True in concept however as in another post I have found other causes of transients. See other post for response Note that Bob has not found these but I have documented some in my upcomming report. Perhaps its not something in most systems but a pix is hard to deny. > > > >If the load dump is a result of disconnecting a charging battery the load > >dump is delivered to the aircraft bus and potential damage can result to > >your avionics. Its likely the OVP will trip but not in time in all cases to > >prevent a short hi voltage pulse on the BUS. The OVP takes some time to > >start clamping (5-10MS?) and much longer (50-100ms) to disconnect the > >alternator thru the "B" lead contactor. Even 5 ms is long with a 60V or > >higher pulse on BUS. > > > >So some of us feel the need for the "Transorb" to keep the BUS voltages > >clamped while the OVP can act. The transorb acts not in 5 MS but in 1/2 pico > >second 10,000+ times faster and faster than any damage can start. > > > >If the failure is a failed hi voltage alternator the transorb clamps the > >voltage while the OVP acts. Both arte needed in the safest system. > > > >If this does not answer your concerns ask more as everyone benefits from > >such a "conversation" > > Agreed! > > Bob . . . > > ________________________________________________________________________________
From: "Paul Messinger" <paulm(at)olypen.com>
Subject: Re: Load Dump Question
Date: Jan 23, 2005
I have found sharp transients on the bus independent of the alternator load dump. Bob has not been able to find any so we disagree. A single 1.5k transorb will clamp any present as well as clamp the OVP trigger while the OVP is in process of clamping the overvoltage. Of coure while the altertnator is connected and you have an alternator load dump transorb that will do the job. A single transorb is under $1 and extra insurance and may or may not bee needed as these transients i have found may not occur in your system. Remember that all alternators inter or external regulated exibit load dumps so its best to have a transorb of hi capacity like the Whackjack which is a convient package of 3 1.5K transorbs in parallel. These devices load share well so normally matching is not needed but at least 3 are needed for a 60amp alternator. Paul ----- Original Message ----- From: "Vincent Welch" <welchvincent(at)hotmail.com> Subject: Re: AeroElectric-List: Load Dump Question > > OK, I'm almost with you Paul. If I place a transorb (say, the Whackjack) on > the alternator side of the B-Lead contactor, doesn't that clamp the entire > line from alternator, through contactor, to the bus? If the battery is > taken offline accidently isn't the bus still clamped through that transorb? > If the B-Lead contactor opens due to the OVP trip won't the bus voltage be > stabilized by the battery? If all of these things are true, why do we need > a second transorb on the bus side? > > If I do need a second transorb on the bus side, is another Whackjack > acceptable or should I use something else? If so, what? > > Vince > > >From: "Paul Messinger" <paulm(at)olypen.com> > >Reply-To: aeroelectric-list(at)matronics.com > >To: > >Subject: Re: AeroElectric-List: Load Dump Question > >Date: Sat, 22 Jan 2005 14:26:53 -0800 > > > > > > > >As I recall the original start of this thread was early last year when > >there > >were failures of Van's rebuilt alternators. Bob and others questioned the > >quality of the rebuilt regulator in the Van's alternator. > > > >Personally I have never seen any real proof of what was the true cause. I > >have real trouble believing Van would sell substandard alternators. ALL > >standard alternator internal regulators are protected against worst case > >load dump. > > > >Any way You are correct that in the case of a real alternator regulator HI > >voltage failure, the only solution is to cut the "B" lead and "so what" if > >that causes an isolated load dump that the alternator cannot take. > > > >However if the alternator is working fine and the battery is disconnected > >the resulting load dump is distributed to the bus and can cause harm > >depending on what is on the bus and how big the load dump is. > > > >There are a couple of solutions to this. First a transorb big enough to > >clamp the load dump hi voltage. This has nothing directly to do with any > >OVP > >device present. > > > >However Bob's crow bar OVP will trigger with the above load dump and this > >results in the hi current during its operation that some of us object to. A > >simple addition of a small value series resistor fixes that. > > > >If the load dump is a result of the "B" lead opening the load dump issue is > >contained to the alternator where you may or may not damage the alternator > >internal regulator. A transorb on the alternator side of the "B" lead > >contactor will protect the alternator if the regulator is not up to the > >task. This is a second transorb as one needs to be on the Bus side also. > > > >If the load dump is a result of disconnecting a charging battery the load > >dump is delivered to the aircraft bus and potential damage can result to > >your avionics. Its likely the OVP will trip but not in time in all cases to > >prevent a short hi voltage pulse on the BUS. The OVP takes some time to > >start clamping (5-10MS?) and much longer (50-100ms) to disconnect the > >alternator thru the "B" lead contactor. Even 5 ms is long with a 60V or


January 16, 2005 - January 23, 2005

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