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 |
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> |
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 |
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 |
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
________________________________________________________________________________
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 |
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
>
>
________________________________________________________________________________
From: | Phil Birkelbach <phil(at)petrasoft.net> |
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> |
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
________________________________________________________________________________
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> |
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
________________________________________________________________________________
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 |
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 |
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
________________________________________________________________________________
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.
________________________________________________________________________________
From: | D Fritz <dfritzj(at)yahoo.com> |
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> |
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 |
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
________________________________________________________________________________
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 |
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 |
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 |
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
________________________________________________________________________________
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> |
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> |
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
________________________________________________________________________________
Subject: | Re: avionics master |
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
>
>
________________________________________________________________________________
From: | Dj Merrill <deej(at)thayer.dartmouth.edu> |
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 |
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> |
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
>
>
________________________________________________________________________________
From: | Kevin Horton <khorton01(at)rogers.com> |
>
>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/
________________________________________________________________________________
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)
>
>
>
>
________________________________________________________________________________
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 |
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 |
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 |
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> |
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> |
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
________________________________________________________________________________
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.
>
________________________________________________________________________________
From: | D Fritz <dfritzj(at)yahoo.com> |
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/"
---------------------------------
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
>
>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 . . .
________________________________________________________________________________
From: | D Fritz <dfritzj(at)yahoo.com> |
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> |
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!
________________________________________________________________________________
From: | Rob Logan <Rob(at)logan.com> |
|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
________________________________________________________________________________
From: | Rob Logan <Rob(at)logan.com> |
|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
________________________________________________________________________________
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 |
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
________________________________________________________________________________
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> |
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
>
>
> ---------------------------------
>
>
________________________________________________________________________________
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 . . .
________________________________________________________________________________
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?
>
________________________________________________________________________________
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 |
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> |
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> |
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> |
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
________________________________________________________________________________
From: | Jay Brinkmeyer <jaybrinkmeyer(at)yahoo.com> |
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> |
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 |
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 |
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 |
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
________________________________________________________________________________
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 . . .
________________________________________________________________________________
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 . . .
________________________________________________________________________________
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 |
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
________________________________________________________________________________
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> |
Thanks Jay, that was just what I was looking for!
Glen Matejcek
aerobubba(at)earthlink.net
________________________________________________________________________________
From: | Ken <klehman(at)albedo.net> |
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> |
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
________________________________________________________________________________
From: | Rob Logan <Rob(at)logan.com> |
|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
________________________________________________________________________________
From: | Rob Logan <Rob(at)logan.com> |
|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 |
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
>
>
________________________________________________________________________________
From: | D Fritz <dfritzj(at)yahoo.com> |
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 |
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
________________________________________________________________________________
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 . . .
________________________________________________________________________________
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 . . .
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
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
________________________________________________________________________________
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 . . .
________________________________________________________________________________
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 . . .
________________________________________________________________________________
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 . . .
________________________________________________________________________________
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 . . .
________________________________________________________________________________
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 . . .
________________________________________________________________________________
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 . . .
________________________________________________________________________________
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 |
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 |
> >> 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
________________________________________________________________________________
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 . . .
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
>
>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 . . .
________________________________________________________________________________
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 . . .
________________________________________________________________________________
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 . . .
________________________________________________________________________________
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 . . .
________________________________________________________________________________
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
________________________________________________________________________________
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> |
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 |
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> |
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)
________________________________________________________________________________
From: | Rob Logan <Rob(at)logan.com> |
> 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
________________________________________________________________________________
From: | Rob Logan <Rob(at)logan.com> |
> 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
________________________________________________________________________________
From: | Rob Logan <Rob(at)logan.com> |
> 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 |
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 |
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> |
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.
________________________________________________________________________________
Thanks Bob and Ken,
Your answers regarding the fuse-link cleared up the mystery. Back to wiring.
JR
________________________________________________________________________________
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 . . .
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
>
>
>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 . . .
________________________________________________________________________________
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 |
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
________________________________________________________________________________
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 |
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 |
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 . . .
________________________________________________________________________________
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> |
> 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.
________________________________________________________________________________
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 |
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 |
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> |
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 |
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.
________________________________________________________________________________
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
________________________________________________________________________________
From: | Mickey Coggins <mick-matronics(at)rv8.ch> |
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 |
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 |
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> |
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 . . .
>
>
________________________________________________________________________________
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> |
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 |
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 |
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> |
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 . . .
>
>
>
________________________________________________________________________________
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> |
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 |
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> |
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 |
>>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 |
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.
________________________________________________________________________________
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 . . .
________________________________________________________________________________
From: | BobsV35B(at)aol.com |
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
________________________________________________________________________________
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 |
> 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?
________________________________________________________________________________
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...)
________________________________________________________________________________
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 |
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> |
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? |
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 |
> 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? |
> 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? |
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.
________________________________________________________________________________
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? |
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 |
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: | "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 . . .
________________________________________________________________________________
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 . . .
________________________________________________________________________________
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 . . .
________________________________________________________________________________
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 |
>
> 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 |
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
>
>
________________________________________________________________________________
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? |
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
________________________________________________________________________________
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 . . .
________________________________________________________________________________
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
________________________________________________________________________________
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 . . .
________________________________________________________________________________
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 . . .
________________________________________________________________________________
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
________________________________________________________________________________
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 . . .
________________________________________________________________________________
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
________________________________________________________________________________
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
________________________________________________________________________________
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)
________________________________________________________________________________
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> |
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)
________________________________________________________________________________
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
>
>
________________________________________________________________________________
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? |
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 |
> 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 |
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 |
> 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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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
>
>
________________________________________________________________________________
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 :).
________________________________________________________________________________
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 |
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 |
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!
________________________________________________________________________________
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 |
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
> >
> >
>
>
________________________________________________________________________________
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.
________________________________________________________________________________
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 |
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 |
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!
________________________________________________________________________________
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
________________________________________________________________________________
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 |
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 |
----- 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 |
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
AeroElectric-Archive.digest.vol-dx