---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Wed 07/12/06: 13 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:21 AM - Re: Grounding lugs and transponder radiation (FLYaDIVE@aol.com) 2. 06:02 AM - Re Blue Mountain EFIS to TruTrak Connection (T. Graziano) 3. 06:03 AM - Re: External voltage regulator Connections (Dennis Haverlah) 4. 08:33 AM - Re: Converting to external regulators (Robert L. Nuckolls, III) 5. 09:53 AM - Re: Converting to external regulators (Brian Lloyd) 6. 10:50 AM - Re: Ammeter Shunt (John Burnaby) 7. 11:01 AM - Re: Ammeter Shunt () 8. 12:31 PM - Transponder and radio to sell (Carlos Trigo) 9. 12:49 PM - Re: Ammeter Shunt (Brian Lloyd) 10. 04:42 PM - Re: Grounding lugs and transponder radiation (europa flugzeug fabrik) 11. 05:57 PM - Re: Ammeter Shunt (Ed Holyoke) 12. 06:09 PM - Re: Re: Grounding lugs and transponder radiation (Brian Lloyd) 13. 06:27 PM - Re: Ammeter Shunt (Brian Lloyd) ________________________________ Message 1 _____________________________________ Time: 01:21:08 AM PST US From: FLYaDIVE@aol.com Subject: Re: AeroElectric-List: Grounding lugs and transponder radiation --> AeroElectric-List message posted by: FLYaDIVE@aol.com In a message dated 7/11/06 10:03:23 PM Eastern Daylight Time, brian-yak@lloyd.com writes: > > Second question regards the transmission of the transponder > > signal. Does the signal rediate from the shaft and the ball or > > only the ball at the tip? > > The signal is radiated only from the shaft of the antenna. The ball > is just there mainly to keep people from getting hurt when they bump > into it. ========================================================== Brian - Group: A bit of clarification: If it is metal and it is attached to the antenna (straight portion of the shaft) it is radiating. There are two reasons for the BALL: 1 - To prevent Corona Discharge - Which is a static discharge that occurs at antenna ends when there is a SHARP mechanical end to an antenna. 2 - As Brian described - It helps prevent injuries when working around the antenna. The other part of the antenna which many tend to forget is the Metal mounting surface - It functions as a Reflector aka Ground Plane (Plane as in an axis ... X, Y or Z. In this case an X axis.) Without it the radiation pattern would be very poor and your transmit & receive signal would be very weak. You would also have a high SWR (Standing Wave Ratio) and that would reduce your signal and shorten the life of the Xponder output circuit. Now, your next question should be: What about planes that are not made out of metal, such as the Long EZ type? Well, they install a [or should install] small metal reflective surface. This can be thin sheet metal or even peel and stick copper tape. It can be mounted directly on the outside of the plane, imbedded into the composite lay-up or on the inside. Only thing that matters is that it is mechanical and electrically connected to the antenna. When doing the math for the construction of the antenna [because all electrical wavelengths are converted to a mechanical wave length or part there of] the Ball must be taken into account for the overall length. This is especially true at the higher frequencies VHF, UHF and Microwave. Transponders are Microwave. Barry "Chop'd Liver" ________________________________ Message 2 _____________________________________ Time: 06:02:12 AM PST US From: "T. Graziano" Subject: AeroElectric-List: Re Blue Mountain EFIS to TruTrak Connection --> AeroElectric-List message posted by: "T. Graziano" I have a BM EFIS Lite G-3 in my Zodiac 601XL and a Trio Avionics EZ Pilot II which accepts NMEA 0183 data stream. Below is an excerpt from my POH on how it works on mine, and also with the Garmin 195 and 296. Note when using the BM EFIS for AP data stream to my EZ Pilot II , I must have the EFIS AP setting on COURSE BUG. Hope this may help. Tony Graziano Zodiac 601XL, N493TG 118 hrs "GENERAL OPERATING INSTURCTIONS ON THE USE OF THE AUTOPILOT: With The Auto Pilot turned ON A. For use with the EFIS providing navigation (the switch below the Autopilot is in the EFIS position): 1. Push the AP Button of the EFIS. 2. Select Source and scroll to and select COURSE BUG 3. Push the SET Button and select the destination and/or the Virtual VOR you wish to go to, 4. Push the DSP Button and select the HSI. 5. Place the Course Bug on the of the GPS Destination or Virtual VOR Pointer using the outer knob 6. Push ON the Servo Button of the Autopilot and the aircraft will turn to and TRACK to the Course Bug Heading. The Autopilot should be in the Track mode. NOTE: The EFIS Course Bug is a heading Bug corrected for wind. In other words, it determines the aircraft's track across the ground regardless of the wind conditions. Be aware that in case of a crosswind, the nose of the aircraft will be pointed into the wind and not to the selected course. Rotate the outer knob on the EFIS to change the course Bug. While flying the Course Bug, the Autopilot will list "BUG" vice a destination. A. For use with the Garmin GPS 295 or 296 (the switch below the Autopilot must be in the Garmin position and the switch below the EFIS switched to either the GPS 296 or to the 295, whichever will be used to provide navigation data.) 1. With a GOTO destination, via any waypoints as selected on the Garmin unit, simply push ON the Autopilot Servo Button and the Autopilot will turn to and track the airplane to the destination. Consult the EZ Pilot Operation and Installation Manual for detailed information on us Time: 04:53:53 AM PST US > From: "Jim Ellis" > Subject: AeroElectric-List: Blue Mountain EFIS to TruTrak Connection > > --> AeroElectric-List message posted by: "Jim Ellis" > > I have been trying to find out if anyone has ever been able to make a working gps > serial connection between a Blue Mountain EFIS and a TruTrak autopilot. I have > made many phone calls and searched all the web sites. > > According the BMA the G3 Lite will provide a gps output through one of its two > serial ports in either GPSS (UPS GPS) or standard NMEA-0183 format. > > OK. > > According to TruTrak their autopilots will accept and read GPSS or NMEA-0183 format > (with the correct baud setting programed into the autopilot). > > OK. > > Now here's the strange part. None of the tech reps at either company can confirm > that their units will work with the other. Nor do they know if anyone anywhere > has ever made a working connection between the two systems. I find this very > odd that the manufacturers don't know the basic compatibility of the equipment > they sell. > > Here is my question for the List. Do you know or have you heard of anyone who has > ever made a working gps serial connection between any Blue Mountain EFIS and > any TruTrak autopilot? If so, I would love to hear from you. > > Jim Ellis > RV9-A, Flying (Yippee!) ________________________________ Message 3 _____________________________________ Time: 06:03:49 AM PST US From: Dennis Haverlah Subject: Re: AeroElectric-List: External voltage regulator Connections --> AeroElectric-List message posted by: Dennis Haverlah Thanks for the advice on connecting the external regulator. I wound up using Bob's Z-23 regulator connection diagram. The alternator is working great!. Thanks Again! Dennis H. > ________________________________ Message 4 _____________________________________ Time: 08:33:26 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Converting to external regulators --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > >George makes a good point that the IVR was designed to work in a specific >way by smart people with lots of money to spend on the problem; a way >that does not include people turning it off and on. Bob makes an >excellent point that the pilot has always had complete control over the >power producing entity, and there is little reason to give that up >now. The choice seems to be that you must choose one or the other. >But wouldn't it be a simple modification to break the wires going to the >field brushes and bring them out to a double throw panel switch? You betcha! But that puts the alternator at-risk for having been 'modified'. Once you open it up, the service life may be affected by the modifier's lack of experience and/or understanding of the recipe for success. If one is willing and able to open any alternator for the purpose of modifying it, then one might as well bring the field leads out for excitation by an externally mounted regulator which offers an opportunity for . . . Adjustability Remote sensing of regulation voltage Graceful, low energy OV management Temperature compensation Easy diagnosis of failures and opportunity to replace a regulator without pulling the alternator. and finally . . . absolute, any time, any conditions control. For all it's virtues the as-supplied, internal regulator offers no better performance than an externally mounted regulator and forces the builder to accept new design goals. If those conditions are acceptable . . . great. If one is desirous of achieving any one or all of the above design goals, then some modifications are necessary. Once you open that puppy up, you might as well make it conform to the classic 'aircraft' configuration. Folks who design cars had NONE of the aforementioned design goals. The present state of the art for automotive alternators has followed a logical and economically sound evolution - for cars. Much of what's been developed and proven in automobiles is slowly and painfully finding its way onto airplanes. However, just because a particular philosophy has become a highly developed, widely accepted practice in cars does not automatically force the airplane builder to give up desirable design goals. > The IVR functionality is maintained, load dump of the field coil has no > where to go (double throw to break both sides of the path > simultaneously), and the pilot has complete control. You only need to open one side. A single pole switch would suffice nicely. Bob . . . --------------------------------------------------------- < What is so wonderful about scientific truth...is that > < the authority which determines whether there can be > < debate or not does not reside in some fraternity of > < scientists; nor is it divine. The authority rests > < with experiment. > < --Lawrence M. Krauss > --------------------------------------------------------- ________________________________ Message 5 _____________________________________ Time: 09:53:08 AM PST US From: Brian Lloyd Subject: Re: AeroElectric-List: Converting to external regulators --> AeroElectric-List message posted by: Brian Lloyd On Jul 12, 2006, at 11:27 AM, Robert L. Nuckolls, III wrote: > For all it's virtues the as-supplied, internal > regulator offers no better performance than an > externally mounted regulator and forces the builder > to accept new design goals. If those conditions are > acceptable . . . great. If one is desirous of > achieving any one or all of the above design goals, > then some modifications are necessary. Once you > open that puppy up, you might as well make it conform > to the classic 'aircraft' configuration. An analogy: would you buy an engine and prop combination that you could not change on your aircraft? They came as a unit and no matter what you did, you could not change the prop to match the operating parameters of your aircraft? I am very much with Bob on this. I want the ability to have complete and total control over my charging system. I cannot do that with an IR alternator. There is no way to force the IR alternator to turn off without modification. (Using the 'I' lead to turn the alternator on or off is dependent on the internal regulator continuing to behave normally and when it is behaving abnormally is precisely the time when I need it to behave normally and turn off when I turn off the 'I' lead.) It is just easier to use an ER alternator and wire up an external regulator. Brian Lloyd 361 Catterline Way brian-yak AT lloyd DOT com Folsom, CA 95630 +1.916.367.2131 (voice) +1.270.912.0788 (fax) I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry ________________________________ Message 6 _____________________________________ Time: 10:50:37 AM PST US From: "John Burnaby" Subject: Re: AeroElectric-List: Ammeter Shunt Brian, Am I understanding correctly, that with a shunt between the alternator and battery, the ammeter will display amp load on the battery when the alternator is off-line? John ________________________________ Message 7 _____________________________________ Time: 11:01:43 AM PST US From: Subject: AeroElectric-List: Re: Ammeter Shunt --> AeroElectric-List message posted by: 7/12/2006 Hello Mark, Thanks for the quick response. You wrote: "In the diagram I have from Dynon it says that if you put the shunt between the alternator and the battery (somewhere in the main power lead from the alternator) it will measure only amps coming from the alternator." Yes, I agree. And those amps will be flowing into both the aircraft systems and into recharging the battery if the voltage regulator is holding the alternator output voltage at a battery charging level. There is no way that I know of to wire the aircraft using only one shunt or Hall effect device in a way that will display the alternator load share between aircraft systems and battery charging. So your three choices are: A) As You wrote: "1. Amps in and out of battery (-60a to 60a)" B) As You wrote: "3. Amps used by aircraft load only." C) Or, Amps flowing out of the alternator to both charge the battery and feed the aircraft systems in some unknown proportion. (Per the diagram from Dynon) So where are you going to put the shunt? OC ----- Original Message ----- Sent: Wednesday, July 12, 2006 10:39 AM Hi, In the diagram I have from Dynon it says that if you put the shunt between the alternator and the battery (somewhere in the main power lead from the alternator) it will measure only amps coming from the alternator. Hope this helps, Mark -----Original Message----- Sent: Tuesday, July 11, 2006 4:41 PM 7/11/2006 Responding to an AeroElectric-List message previously posted by: "Mark Chamberlain" Hello Mark, I would appreciate some help from you and others to better understand this subject. You wrote: "1. Amps in and out of battery (-60a to 60a)" I understand the above statement and how to wire in order to measure all of those amps. If one puts the shunt in the wire going from the battery plus terminal to the input to the battery contactor you will be able (with the proper kind of guage) to measure all of the amps going into and out of the battery itself. This presumes that: A) The alternator B lead is connected to the battery through the contactor output terminal, and B) That you are operating such that you don't have some sort of endurance / essential bus or hot battery bus, also connected directly to the battery plus terminal, that is feeding amps to some portion of the aircraft's system not through the wire going to the battery contactor. You wrote: "3. Amps used by aircraft load only." I understand how this can be measured by placing the shunt in a wire going from the battery contactor output terminal to the aircraft's main power distribution bus. Amps from the alternator, which has its B lead connected to the battery contactor output terminal, and, if need be, amps from the battery, would flow through this shunt to carry the aircraft system's load. Again with no "back door" flows not going through this wire. You wrote: "2. Amps in to the battery from the alternator only." I am not sure what you mean by this statement. Do you mean "Only the amps that are flowing from the alternator into the battery and none of the amps that are flowing from the alternator into the aircraft systems?" Assuming that we are talking about a simple system with only one battery and one alternator there are only two sources of amps possible -- the battery and the alternator. Recall that the amperage flowing into the battery from the alternator is one of the two things being measured as wired in scenario 1 above. Can you please explain what you mean by statement 2 and how one would wire to accomplish it? I know that Bob Nuckolls has a very low opinion of some electrical instrumentation in the aircraft's instrument panel and the pilot's expectations of beneficially using that instrumentation in flight. I am basically in agreement with him and am not trying to wire an airplane. I just want to better understand the concepts involved. Thanks. OC Time: 10:48:18 AM PST US --> AeroElectric-List message posted by: "Mark Chamberlain" Hi All, I am about to install the Dynon Ammeter Shunt that comes with the 180 FlightDeck. It can be installed in 3 locations that can read either: 1. Amps in and out of battery (-60a to 60a), 2. Amps in to the battery from the alternator only 3. Amps used by aircraft load only. My question is: where would be the best location to put it? Suggestions welcomed. Thanks for your help, Mark ________________________________ Message 8 _____________________________________ Time: 12:31:12 PM PST US From: "Carlos Trigo" Subject: AeroElectric-List: Transponder and radio to sell --> AeroElectric-List message posted by: "Carlos Trigo" Hi guys I am a Portuguese homebuilder who is building an RV-9A. Some time ago I bought a NARCO AT 155 transponder, but didn't install yet. Since in Europe it's going to be mandatory next year to have a mode S transponder, I'll have to buy something like a Garmin 330. Therefore, I am willing to sell the Narco AT 155. Although it is brand new, never installed or used, I am accepting less than I payed for it ($1.149). I also bought an ICOM A-200 TSO'd comm radio, which I'm also willing to sell, because I'm thinking in buying a GARMIN SL-40 (or an SL-30 if Santa is generous with me). The ICOM radio is also still in the box, and I also accept less than it's new price ($849). Those interested please contact me offlist. I will go to Oshkosh this year, I can deliver both there. Carlos ________________________________ Message 9 _____________________________________ Time: 12:49:49 PM PST US From: Brian Lloyd Subject: Re: AeroElectric-List: Ammeter Shunt --> AeroElectric-List message posted by: Brian Lloyd On Jul 12, 2006, at 1:42 PM, John Burnaby wrote: > Brian, > > Am I understanding correctly, that with a shunt between the > alternator and battery, the ammeter will display amp load on the > battery when the alternator is off-line? Bob's book explains this better than I can but I will take a stab at it. There is a point in the electrical system where the alternator, the battery, and the distribution bus all connect together. This is usually at the junction of the battery master contactor and the starting contactor. (It may also be at your positive distribution point for your bus.) You can put an ammeter shunt or a hall-effect current sensor in any one of the three wires coming to that point. 1. If you put the shunt in the wire (B-lead) from the alternator, the ammeter will read the current being drawn from the alternator. This is usually called a "load meter". 2. If you put the shunt in the wire going to the distribution bus, the ammeter will read the loads on the electrical system. 3. If you put the shunt in the lead going to the battery, the ammeter will read the current going from the alternator to the battery when the alternator is on-line and the battery is charging (positive amps) or it will read the bus loads if the alternator is off-line (negative amps). This is the typical center-zero battery ammeter you find in most Cessna aircraft. (Piper switched from #3 to #1 somewhere along the line. I think Cessna still uses #3. The only place I have seen #2 is on larger aircraft with multiple charging and load buses.) Bob doesn't like the center-zero battery ammeter (#3) and I have to admit, it is not particularly useful most of the time. When the battery is charging it shows charging current but that drops to zero so you really can't tell anything. OTOH, if the alternator goes off- line, you can see the loads and estimate the remaining battery "run- time" by seeing how many amps you are pulling out of it. If you have a 25AH battery and you are drawing 5A, you can expect the battery to provide power for about 5 hours before it goes dead. (And for those of you who are about to correct me to tell me that when you draw more amps from a battery its amp-hour rating goes down, you are correct but I am trying to make a general point here with relatively simple arithmetic and without a discussion of Peukert's exponent.) The bottom line is that you cannot tell everything about the current flows in your electrical system without at least TWO ammeters. But Bob is certainly right about needing a voltmeter. It is more useful than an ammeter under just about every condition. Brian Lloyd 361 Catterline Way brianl at lloyd dot com Folsom, CA 95630 +1.916.367.2131 (voice) +1.270.912.0788 (fax) "Five percent of the people think. Ten percent of the people think they think. Eighty-five percent of the people would rather die than think." ---Thomas A. Edison Brian Lloyd 361 Catterline Way brian-yak AT lloyd DOT com Folsom, CA 95630 +1.916.367.2131 (voice) +1.270.912.0788 (fax) I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry ________________________________ Message 10 ____________________________________ Time: 04:42:09 PM PST US From: "europa flugzeug fabrik" Subject: AeroElectric-List: Re: Grounding lugs and transponder radiation --> AeroElectric-List message posted by: "europa flugzeug fabrik" brian wrote: > The signal is radiated only from the shaft of the antenna. A couple theoretical texts I have suggest it radiates only from the base of the antenna. Has to do with 90-deg phase lag, current and voltage, I think. The vertical element is there merely to resonate. Dunno also, but the ball has been alleged to be either a capacity hat, or to have proverse effect on radiating pattern. One such allegation came from a retired, aircraft antenna engineer I know. But he thinks my questions are often inane! [Wink] Fred F. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=46771#46771 ________________________________ Message 11 ____________________________________ Time: 05:57:57 PM PST US From: "Ed Holyoke" Subject: RE: AeroElectric-List: Ammeter Shunt --> AeroElectric-List message posted by: "Ed Holyoke" Yeah---but, if the alternator is offline, won't you shut off the contactor to save the 1 amp (and shed loads) and isn't the shunt now offline? Pax, Ed Holyoke -----Original Message----- > 3. If you put the shunt in the lead going to the battery, the ammeter will read the current going from the alternator to the battery when the alternator is on-line and the battery is charging (positive amps) or it will read the bus loads if the alternator is off-line (negative amps). This is the typical center-zero battery ammeter you find in most Cessna aircraft. ________________________________ Message 12 ____________________________________ Time: 06:09:35 PM PST US From: Brian Lloyd Subject: Re: AeroElectric-List: Re: Grounding lugs and transponder radiation --> AeroElectric-List message posted by: Brian Lloyd On Jul 12, 2006, at 7:31 PM, europa flugzeug fabrik wrote: > --> AeroElectric-List message posted by: "europa flugzeug fabrik" > > > > brian wrote: >> The signal is radiated only from the shaft of the antenna. > > A couple theoretical texts I have suggest it radiates only from the > base of the antenna. The entire antenna radiates but most of the radiation comes from the portion of the conductor with the greatest current. Since the current node occurs at the feed point of a 1/4 wave antenna, you are correct in that the portion of the conductor nearer the base radiates more of the signal. Regardless, the entire radiator radiates to one extent or another. If you want you can make a 1/2 wave radiator and feed it at the voltage node (the end). Now you don't need much of a counterpoise (ground) at all because the current is very low at the feedpoint. In that case radiation is primarily from the current node which is now at the center of the radiator. This is commonly used where a ground is not available, such as on plastic cars and boats. > Dunno also, but the ball has been alleged to be either a capacity > hat, or to have proverse effect on radiating pattern. It doesn't really have enough area to be a capacity hat but even so, all that would do is to allow you to reduce the length of the radiator and still be in resonance. It could be a way to reduce corona discharge but the power levels used by transponders is low enough that it really isn't an issue. I don't have any of my antenna books with me but, as I recall, the effective impedance of an end-fed 1/2 wave antenna is about 2000 ohms. Since the voltage node of a 1/4 wave antenna (the free end) should be about the same, I should be able to calculate the voltage at the end of 1/4 wave antenna. Assuming that the 1/4 wave antenna is resonant, the impedance should be 100% resistive so I can use the standard ohms law stuff to calculate voltage. For resistive loads it is: P = V^2/R (power equals voltage squared divide by resistance) If your transponder puts out a peak power of 200W we have: 200 = V^2 / 2000 If we do the algebra we get: V = sqrt (200 * 2000) or 632V I don't think we are going to get a corona discharge from 632V. It could produce a pretty good RF burn if you touch it tho'. (BTW, I could be wrong about the impedance at the voltage node and that would skew things a bit but I am pretty sure I am in the ballpark.) Therefore I hold that the ball is there to keep you from poking holes in yourself should you rise up rapidly whilst cleaning exhaust stains off the belly of your airplane prior to judging at OSH. Brian Lloyd 361 Catterline Way brian-yak AT lloyd DOT com Folsom, CA 95630 +1.916.367.2131 (voice) +1.270.912.0788 (fax) I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry ________________________________ Message 13 ____________________________________ Time: 06:27:25 PM PST US From: Brian Lloyd Subject: Re: AeroElectric-List: Ammeter Shunt --> AeroElectric-List message posted by: Brian Lloyd On Jul 12, 2006, at 8:49 PM, Ed Holyoke wrote: > --> AeroElectric-List message posted by: "Ed Holyoke" > > > Yeah---but, if the alternator is offline, won't you shut off the > contactor to save the 1 amp (and shed loads) and isn't the shunt now > offline? It depends on how you wire your electrical system. If I have 5 hours of battery life including the battery contactor and I have 4 hours of fuel on board ... But if you have a separate battery feed to your endurance bus you might want a second shunt to read loads on the endurance bus. You may want then information to load shed to increase battery endurance. Brian Lloyd 361 Catterline Way brian-yak AT lloyd DOT com Folsom, CA 95630 +1.916.367.2131 (voice) +1.270.912.0788 (fax) I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry