AeroElectric-Archive.digest.vol-kw
February 05, 2012 - March 06, 2012
________________________________________________________________________________
| From: | "Don" <dsvs(at)ca.rr.com> |
| Subject: | Com and Nav Radio and Antenna Questions |
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Sunday, February 05, 2012 6:23 AM
Subject: Re: AeroElectric-List: Com and Nav Radio and Antenna Questions
Bob,
Thanks for the quick response.
Has the ICOM been bench checked? You can ramp check
the radio by standing off a mile or so from the airplane
with a hand held. See if you can talk to each other
on the 122.750 (air-to-air, private aircraft) Unicom
frequency. Use cell phones to know that the individual
in the airplane is talking when indeed you can't hear
him on the hand-held.
A few weeks ago we tried using a hand held with the Archer antenna and it
worked fine. We sent the xcom radio in (sorry I gave the wrong name in
original poat) for testing to the US dealer.
The unit is made in Australia so going back to the manufacturer is very time
consuming. The dealer said everything checked out fine.
One additional item is that the radio has a remote head and no tray as the
more conventional type will not fit in a Pitts
Probably not. The size or shape of the ground
plane will not have so profound an effect on
antenna performance.
Today we tried the handheld with the Archer and the Rami antennas and found
the attis perfectly clear as it had been the last time we tried this.
(should have known that it was not the antenna but believed the dealer when
he said the radio checked out). The radio is going back to the manufacturer.
Bob, after sending the last post I re-read the connection chapter on
antennas base my belief on what I read. Comments? I am interested
in the test set you talked about in the antenna chapter. Thanks in
advance.
The MFJ-259 pictured above is the grand-daddy of
antenna analyzers. It will tell you everything you
need to know about the antenna system. Proble is,
they're kind of pricey. I think I bought my first
one about 10 years ago for under $200. They're pushing
$300 new
This will not break the bank, will purchase one. It does not mention the
ability to excite the feedline and antenna for setting up vor so U will need
help in doing that.
The wingtip antenna you talk about in the connection is a slightly modified
Archer. Archer mounts them to the fiberglass wing tip and sandwiches it
between the glass and the wing root for the ground. I am looking for the
instructions that came with the unit and will send them to you as soon as I
find them. I would like to be able to get one of these. To work in each
wing tip for my two vors. I have an APRS (2meter Jpole in one wingtip that
may make it impossible to get the Archer to work.
I will ask the additional questions after I send you the Archer
instructions.
Bob . . .
________________________________________________________________________________
| Subject: | Cross talk problem |
| From: | "jonlaury" <jonlaury(at)impulse.net> |
Listers.
I have installed an EyeBeam mini in my composite airframe. Unfortunately I do not
have a schematic of the unit, but it uses capacitance (touch) to control the
on/off function and dimming.
The shielded, twisted pair power and ground wire cable parallel unshielded, untwisted
wires to the 4 ohm 1.25" x 1.75" cabin speaker for a distance of about
5' . At that point the cabin speaker pair becomes a twisted and shielded cable.
The two cables parallel each other for an additional 12'. The shield for the
speaker is grounded at the audio panel and the shield for the EB is grounded
at the ship's single point ground bus.
The problem:
When I key the microphone, the EB turns on. If I key it again, the EB begins flashing
uncontrollably. It is unresponsive to the dimming control and the on/off
switch. The only way to stop the flashing is to disconnect the EB from power.
The EB works as intended when connected to battery power independent of the
ship's electrical system.
Attempts at a solution:
Thinking that the the magnetic field of the speaker magnet may be causing the problem,
the speaker was disconnected and the mic was keyed. The EB exhibited the
same uncontrollable flashing upon keying the microphone.
Any ideas on what's happening and/or how to fix it?
Thanks,
John
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=365744#365744
________________________________________________________________________________
| Subject: | Re: Cross talk problem |
| From: | Daniel Hooper <enginerdy(at)gmail.com> |
Try keying the mic without the comm radio on. Chances are it's RF interference.
If that's the case, get a clamp-on ferrite kit and start experimenting.
Touch technology can be very sensitive to RF interference, and that could be leaking
into the power lines from a number of places. For a start, I would recommend
putting a ferrite right at the power input to the light. Another reasonable
place to try is on the speaker line, where it meets the lighting power.
These are made to go around a set of wires (power and ground, power ground and
serial comm) so you should only need one for a given set of wires. ie one for
the speaker wires, one for the EB power lines. They're pretty cheap, so you can
easily pick a few to try out.
To pick some appropriate ones:
Digikey.com
search "ferrite"
Under "Filters" pick "Ferrite Cores and Cables for Wiring (469 Items)
Under "Filter Type" pick "Round Cable, Snap On"
Check the "In Stock" box
Press "Apply Filters"
Pick some with reasonable outer diameters (OD) and inner diameters (ID) that will
fit around your wiring. There are a lot of variables in ferrite selection still,
but in general when choosing between them, higher impedance is better for
you.
--Daniel
On Feb 6, 2012, at 12:47 PM, jonlaury wrote:
>
> Listers.
> I have installed an EyeBeam mini in my composite airframe. Unfortunately I do
not have a schematic of the unit, but it uses capacitance (touch) to control
the on/off function and dimming.
>
> The shielded, twisted pair power and ground wire cable parallel unshielded, untwisted
wires to the 4 ohm 1.25" x 1.75" cabin speaker for a distance of about
5' . At that point the cabin speaker pair becomes a twisted and shielded cable.
The two cables parallel each other for an additional 12'. The shield for
the speaker is grounded at the audio panel and the shield for the EB is grounded
at the ship's single point ground bus.
>
> The problem:
> When I key the microphone, the EB turns on. If I key it again, the EB begins
flashing uncontrollably. It is unresponsive to the dimming control and the on/off
switch. The only way to stop the flashing is to disconnect the EB from power.
The EB works as intended when connected to battery power independent of the
ship's electrical system.
>
> Attempts at a solution:
> Thinking that the the magnetic field of the speaker magnet may be causing the
problem, the speaker was disconnected and the mic was keyed. The EB exhibited
the same uncontrollable flashing upon keying the microphone.
>
> Any ideas on what's happening and/or how to fix it?
>
> Thanks,
> John
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=365744#365744
>
>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Com and Nav Radio and Antenna Questions |
At 07:20 PM 2/5/2012, you wrote:
This will not break the bank, will purchase one. It does not mention
the ability to excite the feedline and antenna for setting up vor so
U will need help in doing that.
This is a self contained antenna analyzer. It features
a variable frequency oscillator that provides a test
signal source over a 2 to 170 Mhz range. There is a
counter that displays the oscillator's present frequency.
Finally, there is an array of detectors upon which a
ratiometric analysis is conducted to deduce the resistive
and reactive components of the antenna and display them.
Instruction manual can be found here:
http://www.mfjenterprises.com/pdffiles/MFJ-259B.pdf
While not a laboratory grade instrument, it's
a lot of bang for the buck.
The wingtip antenna you talk about in the connection is a slightly
modified Archer. Archer mounts them to the fiberglass wing tip and
sandwiches it between the glass and the wing root for the ground. I
am looking for the instructions that came with the unit and will send
them to you as soon as I find them.
Yeah, Bob was a little incensed when the folks
at Van's published dimensional details on his
first RV wingtip offerings (and I repeated them
in the 'Connection). Bottom line is that the antenna
is simply a gamma-matched monopole of which there
are many variations on a theme. The now arcane
'sled runner' marker beacon antennas on the belly
are a good example.
Once you have an MFJ259 in hand, you can both
trim overall length of the Archer design to
desired center frequency, you could also adjust
the gamma-match and tuning capacitor for optimum
performance too.
While this might be an intellectually satisfying
exercise (Hams can get downright pedantic in
their quest for the Holy-SWR), it would be hard
to observe much difference in performance between
an Archer cookie-cutter installation and one that
has be tuned to technical Nirvana.
I would like to be able to get one of these. To work in each wing
tip for my two vors. I have an APRS (2meter Jpole in one wingtip
that may make it impossible to get the Archer to work.
Why a j-pole? That's an awfully big antenna for
a line-of sight application. Why not the simple
vertical whisker?
I will ask the additional questions after I send you the Archer instructions.
Got the data package. What's your question?
Bob . . .
________________________________________________________________________________
| From: | "Don" <dsvs(at)ca.rr.com> |
| Subject: | Com and Nav Radio and Antenna Questions |
I would like to be able to get one of these. To work in each wing
tip for my two vors. I have an APRS (2meter Jpole in one wingtip
that may make it impossible to get the Archer to work.
Why a j-pole? That's an awfully big antenna for
a line-of sight application. Why not the simple
vertical whisker?
Lack of room on the bottom of the AC. Most of the RV's with ATRS installed
use the JPOLE.
One Nav in the right wing with a splitter should work fine.
I will ask the additional questions after I send you the Archer
instructions.
Got the data package. What's your question?
Had to do with why the antenna needed to be as far forward as possible. I
6hink that is to keep the lighting wires that have to run forward after
going halt way up the leading edge "looking like part of the antenna". Also
why the marker beacon antennadid not drain energy to ground. Figured out
that there is no ground plane so no drain to ground.
Thanks for the help and I will let you know what the people at xcom say
about the Pitts radio. Bought the MFJ and I guess I missed the RF signal
generator in the advertisement.
Don
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Com and Nav Radio and Antenna Questions |
>Lack of room on the bottom of the AC. Most of the RV's with ATRS installed
>use the JPOLE.
But that's a 3/4 wavelength antenna. Where do you
stretch out 60" of antenna?
Bob . . .
________________________________________________________________________________
| From: | "Don" <dsvs(at)ca.rr.com> |
| Subject: | Com and Nav Radio and Antenna Questions |
But that's a 3/4 wavelength antenna. Where do you
stretch out 60" of antenna?
With a slight curve it fits in an RV wingtip. The versions that most RV'ers
are using is between 57 and 59 inches long and works fine with a continuous
bow frow front to rear.
Don
________________________________________________________________________________
| From: | "Don" <dsvs(at)ca.rr.com> |
| Subject: | Com and Nav Radio and Antenna Questions |
But that's a 3/4 wavelength antenna. Where do you
stretch out 60" of antenna?
These are the twin lead 300ohm TV cable type and the basic shape of mine is
half an elipse.
Don
________________________________________________________________________________
| From: | Kenneth Johnson <kjohnsondds(at)yahoo.com> |
| Subject: | Re: alternator wiring |
Bob,=0AThe EXP-Bus does provide some OV protection.- In reading informati
on about its use, recommendations suggested not to go above 40 amps.- I h
ave planned to install a 40 amp fusable link before the bus.- I also am i
nstalling both an amp meter and volt meter to monitor electrical flow.- I
know there are several alternatives.- What would you recommend?- Ken J
ohnson=0A=0A=0A=0A________________________________=0A From: "Robert L. Nuck
olls, III" =0ATo: aeroelectric-list@matronic
s.com =0ASent: Sunday, February 5, 2012 1:45 PM=0ASubject: Re: AeroElectric
bert L. Nuckolls, III" =0A=0AAt 12:23 PM 2/5
/2012, you wrote:=0A> Bob, thanks again for your help. I have an EXP-Bus th
at I am using and in which I can connect- for OV protection.- Does the
10 o'clock connection go to this bus?=0A=0A- - The data was not helpful
about the upper-left terminal . . .=0A- - given that it's an internall
y regulated alternator, I=0A- - haven't even got a good guess as to wha
t that terminal=0A- - is for.=0A=0A- - At 70A, it's certainly a rob
ust alternator. But without=0A- - adding a b-lead disconnect contactor,
this style=0A- - of alternator many not be controllable from outside
=0A- - during a runaway OV event. Suggest you consider modifying=0A-
- it for use with an external regulator, ov protection system=0A- - f
===========
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: alternator wiring |
At 06:06 AM 2/7/2012, you wrote:
>Bob,
>The EXP-Bus does provide some OV protection.
But is it compatible with internally regulated alternators?
> In reading information about its use, recommendations suggested
> not to go above 40 amps. I have planned to install a 40 amp
> fusable link before the bus.
Not necessary and probably wouldn't perform as
desired. The EXP bus was crafted for much simpler/
smaller systems. It brings FAT WIRE distribution onto
etched circuit board traces which are vulnerable to
failure under continuous loads. Adding a fusible
is not necessary . . . you just need to limit the
number of electro-whizzies to 40A or less when
everything is turned on.
> I also am installing both an amp meter and volt meter to monitor
> electrical flow. I know there are several alternatives. What
> would you recommend?
My personal choice would be to modify the alternator
for use with an external regulator. Check the
AeroElectric List archives for discussions on
internal failure modes that cannot be controlled
from outside the alternator except by gross
disconnection of the B-lead . . . which is difficult
at best.
An alternator that size will quickly push lots of energy
into your ship's electrical system. Legacy design goals
call for millisecond-fast response to such an event.
These design goals are satisfied by the use of external
regulation and ov protection like that depicted in
the 'Connection's z-figures -OR- modifications like those
crafted by Plane-Power.
Bob . . .
________________________________________________________________________________
| From: | "Dawson-Townsend,Timothy" <tdawson-townsend(at)aurora.aero> |
| Subject: | XM weather receiver? |
Just throwing this out there . . .
I have a portable XM weather data receiver, the older "roundish" style that
has a USB output on it. I'd like to figure out two things:
1) Does someone know the meaning of the status LED? It's either red/green f
lashing or green steady.
2) Does anyone happen to know the pin-out for the J13 8-pin connector on th
e circuit board inside? I know that it is an RS-232 output that one can tap
into, but my old information I have is conflicting . . .
Thanks,
Tim
N52KS
RV-10
________________________________________________________________________________
| From: | Paul Millner <millner(at)me.com> |
>> RV's with ATRS installed use the JPOLE
Are folks using ATRS (APRS?) for sending text messages also? Is there a
WiFi interface to smart phones, or what's the input device of choice?
Paul
________________________________________________________________________________
| Subject: | Re: Com and Nav Radio and Antenna Questions |
| From: | Richard Girard <aslsa.rng(at)gmail.com> |
Bob, I have a question. How much performance degradation, TLAR estimate, is
there from placing a com antenna in a horizontal or near horizontal
position? Are not com radio signals vertically polarized? Doesn't mounting
them horizontally increase there directional selectivity, for lack of
knowing the proper term?
Rick Girard
On Mon, Feb 6, 2012 at 8:20 PM, Robert L. Nuckolls, III <
nuckolls.bob(at)aeroelectric.com> wrote:
> nuckolls.bob(at)aeroelectric.com**>
>
> At 07:20 PM 2/5/2012, you wrote:
>
> This will not break the bank, will purchase one. It does not mention the
> ability to excite the feedline and antenna for setting up vor so U will
> need help in doing that.
>
> This is a self contained antenna analyzer. It features
> a variable frequency oscillator that provides a test
> signal source over a 2 to 170 Mhz range. There is a
> counter that displays the oscillator's present frequency.
> Finally, there is an array of detectors upon which a
> ratiometric analysis is conducted to deduce the resistive
> and reactive components of the antenna and display them.
>
> Instruction manual can be found here:
>
> http://www.mfjenterprises.com/**pdffiles/MFJ-259B.pdf>
>
> While not a laboratory grade instrument, it's
> a lot of bang for the buck.
>
> The wingtip antenna you talk about in the connection is a slightly
> modified Archer. Archer mounts them to the fiberglass wing tip and
> sandwiches it between the glass and the wing root for the ground. I am
> looking for the instructions that came with the unit and will send them to
> you as soon as I find them.
>
> Yeah, Bob was a little incensed when the folks
> at Van's published dimensional details on his
> first RV wingtip offerings (and I repeated them
> in the 'Connection). Bottom line is that the antenna
> is simply a gamma-matched monopole of which there
> are many variations on a theme. The now arcane
> 'sled runner' marker beacon antennas on the belly
> are a good example.
>
> Once you have an MFJ259 in hand, you can both
> trim overall length of the Archer design to
> desired center frequency, you could also adjust
> the gamma-match and tuning capacitor for optimum
> performance too.
>
> While this might be an intellectually satisfying
> exercise (Hams can get downright pedantic in
> their quest for the Holy-SWR), it would be hard
> to observe much difference in performance between
> an Archer cookie-cutter installation and one that
> has be tuned to technical Nirvana.
>
> I would like to be able to get one of these. To work in each wing tip for
> my two vors. I have an APRS (2meter Jpole in one wingtip that may make it
> impossible to get the Archer to work.
>
> Why a j-pole? That's an awfully big antenna for
> a line-of sight application. Why not the simple
> vertical whisker?
>
> I will ask the additional questions after I send you the Archer
> instructions.
>
>
> Got the data package. What's your question?
>
>
> Bob . . .
>
>
--
Zulu Delta
Mk IIIC
Thanks, Homer GBYM
It isn't necessary to have relatives in Kansas City in order to be unhappy.
- Groucho Marx
________________________________________________________________________________
| Subject: | Re: Cross talk problem |
| From: | "jonlaury" <jonlaury(at)impulse.net> |
Daniel,
Thanks for that. I'll give it a try.
> Another reasonable place to try is on the speaker line, where it meets the lighting
power.
Do you mean where the two sets of wires come together from their respective sources
of Audio Panel and the power/ground bus's, or from the appliance ends at
the speaker and light? Does it matter? The appliance ends are right next to each
other in a small overhead console and their wire runs are parallel for about
17', the first 5' of speaker wire being unshielded/untwisted.
Best,
John
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=365807#365807
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Com and Nav Radio and Antenna Questions |
At 09:56 AM 2/7/2012, you wrote:
>Bob, I have a question. How much performance degradation, TLAR
>estimate, is there from placing a com antenna in a horizontal or
>near horizontal position? Are not com radio signals vertically
>polarized? Doesn't mounting them horizontally increase there
>directional selectivity, for lack of knowing the proper term?
The ONLY time that an antenna delivers on it's theoretical
performance (radiation efficiency and patters) is on the
antenna test range under controlled conditions.
Many antennas can approach theoretical performance in service
when situated in free space and "ground" configurations
that are large compared to the frequency of interest.
In other words, antennas for GPS and transponders at
1000+ MHz do pretty well.
As you go down in frequency, it becomes increasingly
difficult to configure an antenna installation that
even approaches theoretical performance. On small structures
like airplanes with lots of 'sticky-outs' (wings, stabilizers,
landing gear, whirring props, other antennas, etc) both
radiation pattern and polarity are distorted. Out
in the vacuum of space, the theoretical loss for
a vertical antenna talking to a horizontal antenna is
huge . . . in practice here on the ground antenna range,
it's on the order of 10-20 dB. But these will be "centered
up" measurements where the two antennas are looking right
at each other.
However, as soon as you bolt the antenna to an airplane,
one's ability to predict performance variables goes down.
Someone who has measured the effects of vertical vs. horizontal
polarization on airplanes like yours might offer some
advice based on experience, but I've never met an RF guru
who would attempt to put a quantitative answer to your
question without going out to measure it - a difficult
task at best. RF squirted from (or at) your airplane's
compromised antenna is subject to MANY unpredictable
variables.
Once you've relocated your antenna, YOU are going to
become the AeroElectric-List guru for having carried out
the experiment. Put the second antenna on along with
a switch that will let you switch quickly between the
'compromised' and 'optimized' antennas. Do some listening
tests with weak stations as you fly a 360 pattern listening
for 'hot' and 'dead' spots while making not of the relative
signal strength of 'compromised' vs. 'optimized' antennas.
We conducted similar tests on our production aircraft
using a ground station at the field for a signal source.
Automated acquisition systems would gather data on
received signal strengths as the airplane maneuvers.
But attempting to predict relative antenna performance
without conducting real tests is sorta like hypothesizing
about "The theory of everything".
Here's some further reading on the topic.
http://www.astronwireless.com/topic-archives-selecting-antennas.asp
http://www.astronwireless.com/topic-archives-antennas-polarization.asp
http://home.comcast.net/~n9rla/Antenna_Polarization.PDF
Bob . . .
________________________________________________________________________________
| Subject: | DraftSight CAD WARNING |
| From: | Richard Girard <aslsa.rng(at)gmail.com> |
I made the mistake of downloading the latest release R1.4 today. It crashes
randomly. I've tried deleting all previous versions, cleaning the registry
before downloading it, nothing seems to work. I've also found that the
circle function will not work if you specify a radius, it only works when
you specify diameter. That doesn't seem to be related to the crashing.
Anyway, if you're a DraftSight user be very wary of making an upgrade to
this release.
Rick Girard
PS I should add that I have run the previous releases for almost two years
and NEVER had a crash before.
--
Zulu Delta
Mk IIIC
Thanks, Homer GBYM
It isn't necessary to have relatives in Kansas City in order to be unhappy.
- Groucho Marx
________________________________________________________________________________
| From: | "Don" <dsvs(at)ca.rr.com> |
APRS is only available to ham operators and uses a two meter packet radio.
No text. No wifi.
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Paul
Millner
Sent: Tuesday, February 07, 2012 7:46 AM
Subject: AeroElectric-List: APRS / ATRS
>> RV's with ATRS installed use the JPOLE
Are folks using ATRS (APRS?) for sending text messages also? Is there a
WiFi interface to smart phones, or what's the input device of choice?
Paul
________________________________________________________________________________
| From: | Daniel Hooper <enginerdy(at)gmail.com> |
I think I read about someone experimenting with a MicroTrak4 in their airplane...
http://www.byonics.com/mt-tt4
Unlike the other MicroTracks, it has a receiver on it as well, so it is capable
of receiving text.
I'm not sure about a wifi interface, but a bluetooth-serial interface for handling
APRS messages would be a pretty simple (relatively speaking) hack for android
devices.
That'd be pretty slick!
On Feb 7, 2012, at 9:46 AM, Paul Millner wrote:
>
> >> RV's with ATRS installed use the JPOLE
>
> Are folks using ATRS (APRS?) for sending text messages also? Is there a WiFi
interface to smart phones, or what's the input device of choice?
>
> Paul
>
>
>
>
>
________________________________________________________________________________
| Subject: | Re: Cross talk problem |
| From: | Daniel Hooper <enginerdy(at)gmail.com> |
I meant where the speaker line joins the light power wiring at the panel. If it's
RF, it's leaking in from somewhere, and you need to separate that source from
the problem area.
Another possibility is clamping the ferrite mid-way down the line, on both lines
separately, or just clamping the entire bundle with one larger ferrite.
You are trying to isolate the noise source from the rest of the system (particularly
the touch-light). If you have wires bundled together, or running near each
other, RF can jump across cables. Ferrites kill the RF, but if, for example,
you put just one ferrite on the power, midway down the 17' run, the RF energy
will have no problem jumping from one cable to the other freely, bypassing the
ferrite filter.
Have you tried the experiment with the comm radio off? The RF theory sounds good,
but it's best to rule easy things out if you can, even if it sounds unlikely.
On Feb 7, 2012, at 10:54 AM, jonlaury wrote:
>
> Daniel,
> Thanks for that. I'll give it a try.
>
>
>> Another reasonable place to try is on the speaker line, where it meets the lighting
power.
>
>
> Do you mean where the two sets of wires come together from their respective sources
of Audio Panel and the power/ground bus's, or from the appliance ends at
the speaker and light? Does it matter? The appliance ends are right next to
each other in a small overhead console and their wire runs are parallel for about
17', the first 5' of speaker wire being unshielded/untwisted.
>
> Best,
> John
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=365807#365807
>
>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | Dj Merrill <deej(at)deej.net> |
On 02/07/2012 11:36 PM, Don wrote:
>
> APRS is only available to ham operators and uses a two meter packet radio.
> No text. No wifi.
Actually, you can send and receive text messages with APRS. In You'd
need to have the appropriate transmitter, receiver, display, and
keyboard in the plane to do so, but it is certainly possible.
-Dj
--
Dj Merrill - N1JOV
Sportsman 2+2 Builder #7118 N421DJ - http://deej.net/sportsman/
Glastar Flyer N866RH - http://deej.net/glastar/
________________________________________________________________________________
| From: | Sean Stephens <sean(at)stephensville.com> |
On 2/7/12 11:28 PM, Daniel Hooper wrote:
> --> AeroElectric-List message posted by: Daniel Hooper
>
> I think I read about someone experimenting with a MicroTrak4 in their airplane...
> http://www.byonics.com/mt-tt4
From a while ago, but great info...
http://home.hiwaay.net/~sbuc/journal/tracker.htm
Also, here's info on setting up your own APRS iGate...
http://www.vansairforce.com/community/showthread.php?t=30180
-Sean
________________________________________________________________________________
| Subject: | Re: Cross talk problem |
| From: | "jonlaury" <jonlaury(at)impulse.net> |
> I meant where the speaker line joins the light power wiring at the panel.
OK, I think I get the idea. The two cables are not co-located at the power end
(one comes out of the audio panel, one comes from the battery bus) so I'll try
putting a ferrite on the speaker cable at the point of convergence. I gather
that this is not an exact science, so I'll try the different locations that you
suggest.
Haven't had a chance to try with the com radio off. But the problem goes away
with the audio panel off, or (IIRC) with the speaker button deselected with the
AP on.
Right now I'm focused on getting my W&B done and anything else for my DAR appointment.
Thanks
John
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=365879#365879
________________________________________________________________________________
| From: | Paul Millner <millner(at)me.com> |
Hi Don,
I'm a ham; note that APRS began as a general text service. The geo
updating's become the killer app, but hardly the only... some folks use
it for remote weather stations, other things.
So it certainly supports text messages... I'm just looking for a low
barrier of entry approach to doing so airborne. Thanks for your
thought, incorrect though it may be! :-)
Paul
On 2/7/2012 8:36 PM, Don wrote:
> --> AeroElectric-List message posted by: "Don"
>
> APRS is only available to ham operators and uses a two meter packet radio.
> No text. No wifi.
>
________________________________________________________________________________
| From: | Hopperdhh(at)aol.com |
| Subject: | King KR-86 Loop Cable |
I have a KR-86 ADF receiver and KA42 loop antenna, but no cable. I'd like
to fabricate a cable.
Apparently the capacitance of the cable is critical. Can anyone tell me
what this capacitance should be and how to measure it? Also, is the cable 2
separately shielded twisted pairs, or can the twisted pairs both be in the
same shield, like telephone cable?
Thanks, Dan K9WEK
RV-7A 766DH flying since 2001
________________________________________________________________________________
| From: | Robert Borger <rlborger(at)mac.com> |
| Subject: | Red Dot Digital SWR Meter |
Bob,
The Red Dot Digital SWR Meter that I ordered last week has arrived from China.
Here's a picture of the front:
It appears very well built with a steel(?) case.
Here's a picture of the back:
Now for the best part. Here's a scan of the instructions, front and back:
Do we have a Chinese translator in the house?
It appears that it takes 3 AAA batteries. I'll have to remove the back and confirm
that it looks like the picture and put some batteries in it.
I think I'll wait until you have had the opportunity to test the one you have on
order before I go any further than that.
Blue skies & tailwinds,
Bob Borger
Europa XS Tri, Rotax 914, Airmaster C/S Prop.
Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP
3705 Lynchburg Dr.
Corinth, TX 76208-5331
Cel: 817-992-1117
rlborger(at)mac.com
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: King KR-86 Loop Cable |
At 03:15 PM 2/8/2012, you wrote:
>
>I have a KR-86 ADF receiver and KA42 loop antenna, but no
>cable. I'd like to fabricate a cable.
>
>Apparently the capacitance of the cable is critical. Can anyone
>tell me what this capacitance should be and how to measure
>it? Also, is the cable 2 separately shielded twisted pairs, or can
>the twisted pairs both be in the same shield, like telephone cable?
Not sure without schematics and a service
manual. There have been numerous service bulletins
over the years that called for confirmation
of a sense or loop cable assembly's capacitance.
For many radios of the era, coax capacitance
was an integral component of resonant or reactive
circuits within the receiver.
I recall writing accessory kits for ADF installations
wherein the installer fabricated a sense antenna
coax from some weird coax with a very tiny center
conductor in a relatively large hollow insulator
sleeve. Car radios used to use the same stuff . . .
very LOW capacitance/foot was key. Here's a tid-bit
I found on the 'net about low cap receiving coax:
The real reason car radios used ~90 ohm coax is 90-95 ohms works out
to be the very highest impedance practical in a coaxial line having
minimum possible shunt capacitance and reasonable outer and workable
conductor size. This is entirely because of the short unloaded whip
antenna on the car, and the AM broadcast bands low frequency that
makes the antenna the tiniest fraction of a wave tall. The small car
antenna is a voltage probe on AM broadcast. The short car antenna is
an extremely high impedance source on the AM band. The AM receiver
has a very high input impedance, ideally hundreds or thousands of
ohms. Any shunt capacitance to ground in the connection between the
receiver and antenna forms the lower leg of a voltage divider that
reduces the RF voltage available at the AM radio input.
The car system is not operating in a normal transmission line mode.
This type of cable was also used for some old data lines, and it can
work as a transmission line, but generally it is pretty lossy
compared to other cables. After all, nearly all HF and VHF loss is
caused by conductor resistance and this cable has a pretty thin
center conductor.
As the article states, coax used in this application
is not behaving like a matched transmission line but
simply a shielded wire chosen to minimize the upset
for very high impedance receiver front ends.
RG62 is the only modern coax I can find with a low
capacitance (13.0 pf/ft). You could probably make
a new cable from this stuff if you knew what the total
allowable capacitance was . . . this sets cable
length.
These folks offer cables for KR-76 in various
lengths. Perhaps they fabricate them locally.
http://www.bennettavionics.com/kr86system.html
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Red Dot Digital SWR Meter |
At 05:43 PM 2/8/2012, you wrote:
>Bob,
>
>The Red Dot Digital SWR Meter that I ordered last week has arrived from China.
>Here's a picture of the front:
>
>It appears very well built with a steel(?) case.
>
>Here's a picture of the back:
>
>Now for the best part. Here's a scan of the instructions, front and back:
I think mine is here too. Need to get to the PO Box in
the morning. I've looked for an English instruction
manual but nothing turned up in the time I had.
I did find this narrative by a user:
Specifications:
MAX.POWER 120W
V.S.W.R 1.00~19.9
FREQUENCY RANGE VHF(145mhz) / UHF(45mhz)
COVER:100mhz~500mhz
ONSERTION LOSS < 0.15dB(VHF) , < 0.25dB(UHF)
TEMPERATURE 0?~70?
BATTERY
3 x AAA Type Battery or Rechargeable <2mA
(battery not included in this sale)
SZIE 66*68*37 (mm)
INTERFACE N(SL16)
WEIGHT 260g (without battery)
Instructions:
Battery installation: Remove 4 black round screws on the corner of
back cover and open it. Install 3 AAA batteries. BE CAUTIOUS to the
polarities. Put the cover on and fasten the screws. IMPROPER
INSTALLATION OF BACK COVER WILL CAUSE ERROR ON U-BAND MEASUREMENT!
Connect the Output of your transceiver to "TX" and Antenna or Load to
"ANT". NOTE: UV-Band meter utilize "N" type connectors; and"SL16"
connectors (normally named "M" connecter) for HF-Band. Proper
adaptor/cable is required if your device has different type of connectors.
Press the red button to power on. After 2 seconds of LCD self test,
it's ready for normal measurement.
UV-Band meter will display in sequence:"+ XXX P" (pass through
power),"- XXX P" (feed back power)," XXX G" (SWR value), 2 seconds
display for each mode. Press the red button will hold the current
display. Press it again to continue the display.
Under the environment of night or weak illumination, just press and
hold the red button for 1 second to turn the blue back light on.
Press and hold the red button for 1 second again to turn it off.
8 minutes after no power was measured, it will power off
automatically. Press and hold the red button for 2 seconds to turn
off manually.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Red Dot Digital SWR Meter |
| From: | Robert Borger <rlborger(at)mac.com> |
Bob,
Thanks for the quick reply. One last question. After you power up the SWR Meter,
do you transmit on the radio to get the readings or does it magically throw
electrons about to get the readings?
I'll take it to the hanger tomorrow and, with any luck, I'll be able to give it
a test.
Blue skies & tailwinds,
Bob Borger
Europa XS Tri, Rotax 914, Airmaster C/S Prop.
Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP
3705 Lynchburg Dr.
Corinth, TX 76208-5331
Cel: 817-992-1117
rlborger(at)mac.com
On Feb 8, 2012, at 7:07 PM, Robert L. Nuckolls, III wrote:
>
> At 05:43 PM 2/8/2012, you wrote:
>> Bob,
>>
>> The Red Dot Digital SWR Meter that I ordered last week has arrived from China.
>> Here's a picture of the front:
>>
>> It appears very well built with a steel(?) case.
>>
>> Here's a picture of the back:
>>
>> Now for the best part. Here's a scan of the instructions, front and back:
>
>
> I think mine is here too. Need to get to the PO Box in
> the morning. I've looked for an English instruction
> manual but nothing turned up in the time I had.
>
> I did find this narrative by a user:
>
> Specifications:
>
> MAX.POWER 120W
> V.S.W.R 1.00~19.9
> FREQUENCY RANGE VHF(145mhz) / UHF(45mhz)
> COVER:100mhz~500mhz
> ONSERTION LOSS < 0.15dB(VHF) , < 0.25dB(UHF)
> TEMPERATURE 0?~70?
> BATTERY
> 3 x AAA Type Battery or Rechargeable <2mA
>
> (battery not included in this sale)
>
> SZIE 66*68*37 (mm)
> INTERFACE N(SL16)
> WEIGHT 260g (without battery)
> Instructions:
>
> Battery installation: Remove 4 black round screws on the corner of back cover
and open it. Install 3 AAA batteries. BE CAUTIOUS to the polarities. Put the
cover on and fasten the screws. IMPROPER INSTALLATION OF BACK COVER WILL CAUSE
ERROR ON U-BAND MEASUREMENT!
>
> Connect the Output of your transceiver to "TX" and Antenna or Load to "ANT".
NOTE: UV-Band meter utilize "N" type connectors; and"SL16" connectors (normally
named "M" connecter) for HF-Band. Proper adaptor/cable is required if your device
has different type of connectors.
>
> Press the red button to power on. After 2 seconds of LCD self test, it's ready
for normal measurement.
>
> UV-Band meter will display in sequence:"+ XXX P" (pass through power),"- XXX
P" (feed back power)," XXX G" (SWR value), 2 seconds display for each mode. Press
the red button will hold the current display. Press it again to continue the
display.
>
> Under the environment of night or weak illumination, just press and hold the
red button for 1 second to turn the blue back light on. Press and hold the red
button for 1 second again to turn it off.
>
> 8 minutes after no power was measured, it will power off automatically. Press
and hold the red button for 2 seconds to turn off manually.
>
>
>
> Bob . . .
>
>
>
>
________________________________________________________________________________
| From: | "Michael McMahon" <mike(at)aeromotogroup.com> |
| Subject: | For Sale: Two Cheltons, EI MVP-50, Pinpoint ADAHRS |
and Spare Smart Data Cards
For Sale:
* Dual screen Chelton with EIU and Pinpoint, brand new and unopened in the
box in which it was shipped to me from Lancair
* Single screen EFIS with Watson purchased from Greg Poe via eBay in 2004,
never touched since arrival
* Pinpoint ADAHRS (NO GPS) purchased from SteinAir
* Garmin GPS35 antenna to provide GPS signal to Pinpoint ADAHRS (other
antennae work, too)
* Electronics International MVP50 six cylinder with all sensors etc. still
in all the original plastic and bubble wrap
* Two extra Smart Data cards, unused
When there's money to buy avionics, there's no time to build. When there's
time to build, there's not enough money to justify hanging onto the
avionics!
Please contact me with any questions at afm528 (AT) gmail (DOT) com. I'm
motivated, make me a fair offer and it's yours. I'll be posting on a couple
other forums, then eBay if nobody from the forums is interested. Thank you
for looking.
Please forward to anyone you know who might be interested, I'd appreciate
it.
Thank you,
Mike
Lancair ES N9637M (in progress)
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert
Borger
Sent: Wednesday, February 08, 2012 6:03 PM
Subject: Re: AeroElectric-List: Red Dot Digital SWR Meter
-->
Bob,
Thanks for the quick reply. One last question. After you power up the SWR
Meter, do you transmit on the radio to get the readings or does it magically
throw electrons about to get the readings?
I'll take it to the hanger tomorrow and, with any luck, I'll be able to give
it a test.
Blue skies & tailwinds,
Bob Borger
Europa XS Tri, Rotax 914, Airmaster C/S Prop.
Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP
3705 Lynchburg Dr.
Corinth, TX 76208-5331
Cel: 817-992-1117
rlborger(at)mac.com
On Feb 8, 2012, at 7:07 PM, Robert L. Nuckolls, III wrote:
> -->
>
> At 05:43 PM 2/8/2012, you wrote:
>> Bob,
>>
>> The Red Dot Digital SWR Meter that I ordered last week has arrived from
China.
>> Here's a picture of the front:
>>
>> It appears very well built with a steel(?) case.
>>
>> Here's a picture of the back:
>>
>> Now for the best part. Here's a scan of the instructions, front and
back:
>
>
> I think mine is here too. Need to get to the PO Box in the morning.
> I've looked for an English instruction manual but nothing turned up
> in the time I had.
>
> I did find this narrative by a user:
>
> Specifications:
>
> MAX.POWER 120W
> V.S.W.R 1.00~19.9
> FREQUENCY RANGE VHF(145mhz) / UHF(45mhz) COVER:100mhz~500mhz ONSERTION
> LOSS < 0.15dB(VHF) , < 0.25dB(UHF) TEMPERATURE 0?~70?
> BATTERY
> 3 x AAA Type Battery or Rechargeable <2mA
>
> (battery not included in this sale)
>
> SZIE 66*68*37 (mm)
> INTERFACE N(SL16)
> WEIGHT 260g (without battery)
> Instructions:
>
> Battery installation: Remove 4 black round screws on the corner of back
cover and open it. Install 3 AAA batteries. BE CAUTIOUS to the polarities.
Put the cover on and fasten the screws. IMPROPER INSTALLATION OF BACK COVER
WILL CAUSE ERROR ON U-BAND MEASUREMENT!
>
> Connect the Output of your transceiver to "TX" and Antenna or Load to
"ANT". NOTE: UV-Band meter utilize "N" type connectors; and"SL16" connectors
(normally named "M" connecter) for HF-Band. Proper adaptor/cable is required
if your device has different type of connectors.
>
> Press the red button to power on. After 2 seconds of LCD self test, it's
ready for normal measurement.
>
> UV-Band meter will display in sequence:"+ XXX P" (pass through power),"-
XXX P" (feed back power)," XXX G" (SWR value), 2 seconds display for each
mode. Press the red button will hold the current display. Press it again to
continue the display.
>
> Under the environment of night or weak illumination, just press and hold
the red button for 1 second to turn the blue back light on. Press and hold
the red button for 1 second again to turn it off.
>
> 8 minutes after no power was measured, it will power off automatically.
Press and hold the red button for 2 seconds to turn off manually.
>
>
>
> Bob . . .
>
>
>
>
________________________________________________________________________________
| From: | David <ainut(at)knology.net> |
| Subject: | Re: For Sale: Two Cheltons, EI MVP-50, Pinpoint ADAHRS |
and Spare Smart Data Cards
It ALWAYS helps if you give some idea of the prices you're looking for.
David M.
Michael McMahon wrote:
> --> AeroElectric-List message posted by: "Michael McMahon"
>
> For Sale:
>
> * Dual screen Chelton with EIU and Pinpoint, brand new and unopened in the
> box in which it was shipped to me from Lancair
> * Single screen EFIS with Watson purchased from Greg Poe via eBay in 2004,
> never touched since arrival
> * Pinpoint ADAHRS (NO GPS) purchased from SteinAir
>
> * Garmin GPS35 antenna to provide GPS signal to Pinpoint ADAHRS (other
> antennae work, too)
>
> * Electronics International MVP50 six cylinder with all sensors etc. still
> in all the original plastic and bubble wrap
>
> * Two extra Smart Data cards, unused
>
> When there's money to buy avionics, there's no time to build. When there's
> time to build, there's not enough money to justify hanging onto the
> avionics!
>
>
> Please contact me with any questions at afm528 (AT) gmail (DOT) com. I'm
> motivated, make me a fair offer and it's yours. I'll be posting on a couple
> other forums, then eBay if nobody from the forums is interested. Thank you
> for looking.
>
> Please forward to anyone you know who might be interested, I'd appreciate
> it.
>
> Thank you,
>
> Mike
> Lancair ES N9637M (in progress)
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert
> Borger
> Sent: Wednesday, February 08, 2012 6:03 PM
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: Red Dot Digital SWR Meter
>
> --> AeroElectric-List message posted by: Robert Borger
> -->
>
> Bob,
>
> Thanks for the quick reply. One last question. After you power up the SWR
> Meter, do you transmit on the radio to get the readings or does it magically
> throw electrons about to get the readings?
>
> I'll take it to the hanger tomorrow and, with any luck, I'll be able to give
> it a test.
>
> Blue skies& tailwinds,
> Bob Borger
> Europa XS Tri, Rotax 914, Airmaster C/S Prop.
> Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP
> 3705 Lynchburg Dr.
> Corinth, TX 76208-5331
> Cel: 817-992-1117
> rlborger(at)mac.com
>
> On Feb 8, 2012, at 7:07 PM, Robert L. Nuckolls, III wrote:
>
>
>> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
>> -->
>>
>> At 05:43 PM 2/8/2012, you wrote:
>>
>>> Bob,
>>>
>>> The Red Dot Digital SWR Meter that I ordered last week has arrived from
>>>
> China.
>
>>> Here's a picture of the front:
>>>
>>> It appears very well built with a steel(?) case.
>>>
>>> Here's a picture of the back:
>>>
>>> Now for the best part. Here's a scan of the instructions, front and
>>>
> back:
>
>>
>> I think mine is here too. Need to get to the PO Box in the morning.
>> I've looked for an English instruction manual but nothing turned up
>> in the time I had.
>>
>> I did find this narrative by a user:
>>
>> Specifications:
>>
>> MAX.POWER 120W
>> V.S.W.R 1.00~19.9
>> FREQUENCY RANGE VHF(145mhz) / UHF(45mhz) COVER:100mhz~500mhz ONSERTION
>> LOSS< 0.15dB(VHF) ,< 0.25dB(UHF) TEMPERATURE 0?~70?
>> BATTERY
>> 3 x AAA Type Battery or Rechargeable<2mA
>>
>> (battery not included in this sale)
>>
>> SZIE 66*68*37 (mm)
>> INTERFACE N(SL16)
>> WEIGHT 260g (without battery)
>> Instructions:
>>
>> Battery installation: Remove 4 black round screws on the corner of back
>>
> cover and open it. Install 3 AAA batteries. BE CAUTIOUS to the polarities.
> Put the cover on and fasten the screws. IMPROPER INSTALLATION OF BACK COVER
> WILL CAUSE ERROR ON U-BAND MEASUREMENT!
>
>> Connect the Output of your transceiver to "TX" and Antenna or Load to
>>
> "ANT". NOTE: UV-Band meter utilize "N" type connectors; and"SL16" connectors
> (normally named "M" connecter) for HF-Band. Proper adaptor/cable is required
> if your device has different type of connectors.
>
>> Press the red button to power on. After 2 seconds of LCD self test, it's
>>
> ready for normal measurement.
>
>> UV-Band meter will display in sequence:"+ XXX P" (pass through power),"-
>>
> XXX P" (feed back power)," XXX G" (SWR value), 2 seconds display for each
> mode. Press the red button will hold the current display. Press it again to
> continue the display.
>
>> Under the environment of night or weak illumination, just press and hold
>>
> the red button for 1 second to turn the blue back light on. Press and hold
> the red button for 1 second again to turn it off.
>
>> 8 minutes after no power was measured, it will power off automatically.
>>
> Press and hold the red button for 2 seconds to turn off manually.
>
>>
>>
>> Bob . . .
>>
>>
>>
>>
>>
>
>
>
--
Tell the truth. Be honest. Be responsible to and for yourself.
We want our freedoms back. Strike the illegal legislations called: 1) obamacare,
2) "Patriot (HA!) Act", and 3) 'presidential orders' that affect anyone besides
gubmnt worker bees.
Hate crime laws? Really? Thought police? Orwell would be proud.
Every gram of cocaine you buy from elsewhere contributes to an innocent being murdered
in Central and South America. Grow your own or Stop taking it.
________________________________________________________________________________
| From: | Hopperdhh(at)aol.com |
| Subject: | Re: King KR-86 Loop Cable |
Thanks Bob,
I have the service manual, but there is no hint of what the capacitance or
impedance is of the loop cables. It does show the cable as 2 separately
shielded 2 conductor cables. The install manual gives 2 part numbers of
cables (different lengths) and also says to not alter the length. One is 15 ft.
and one is 24 ft.
I bought this radio and antenna at OSH for, I think, $25. I repaired the
radio -- found a leaky capacitor in the synthesizer loop filter which caused
a loud 1 KHz noise that covered up all signals.
This is just a hobby project, so I don't want to spend lots of money on
it. I've already spent twice as much on manuals as the radio cost!
I am a EE, and have been a ham for over 50 years, built a lot of
equipment, etc. There should be a way to solve this problem, but so far I haven't
been able to! I'll try some things -- like measure the antenna inductance to
get an idea of the impedance we're dealing with. I can also make some
measurement on the goniometer, and front end coils that it feeds. That gets a
little complicated!
Thanks for the help. If anything else comes to mind please let me know.
Dan
In a message dated 2/8/2012 7:47:36 P.M. Eastern Standard Time,
nuckolls.bob(at)aeroelectric.com writes:
At 03:15 PM 2/8/2012, you wrote:
I have a KR-86 ADF receiver and KA42 loop antenna, but no cable. I'd like
to fabricate a cable.
Apparently the capacitance of the cable is critical. Can anyone tell me
what this capacitance should be and how to measure it? Also, is the cable 2
separately shielded twisted pairs, or can the twisted pairs both be in the
same shield, like telephone cable?
Not sure without schematics and a service
manual. There have been numerous service bulletins
over the years that called for confirmation
of a sense or loop cable assembly's capacitance.
For many radios of the era, coax capacitance
was an integral component of resonant or reactive
circuits within the receiver.
I recall writing accessory kits for ADF installations
wherein the installer fabricated a sense antenna
coax from some weird coax with a very tiny center
conductor in a relatively large hollow insulator
sleeve. Car radios used to use the same stuff . . .
very LOW capacitance/foot was key. Here's a tid-bit
I found on the 'net about low cap receiving coax:
The real reason car radios used ~90 ohm coax is 90-95 ohms works out to be
the very highest impedance practical in a coaxial line having minimum
possible shunt capacitance and reasonable outer and workable conductor size.
This is entirely because of the short unloaded whip antenna on the car, and
the AM broadcast bands low frequency that makes the antenna the tiniest
fraction of a wave tall. The small car antenna is a voltage probe on AM
broadcast. The short car antenna is an extremely high impedance source on the
AM
band. The AM receiver has a very high input impedance, ideally hundreds or
thousands of ohms. Any shunt capacitance to ground in the connection between
the receiver and antenna forms the lower leg of a voltage divider that
reduces the RF voltage available at the AM radio input.
The car system is not operating in a normal transmission line mode.
This type of cable was also used for some old data lines, and it can work
as a transmission line, but generally it is pretty lossy compared to other
cables. After all, nearly all HF and VHF loss is caused by conductor
resistance and this cable has a pretty thin center conductor.
As the article states, coax used in this application
is not behaving like a matched transmission line but
simply a shielded wire chosen to minimize the upset
for very high impedance receiver front ends.
RG62 is the only modern coax I can find with a low
capacitance (13.0 pf/ft). You could probably make
a new cable from this stuff if you knew what the total
allowable capacitance was . . . this sets cable
length.
These folks offer cables for KR-76 in various
lengths. Perhaps they fabricate them locally.
_http://www.bennettavionics.com/kr86system.html_
(http://www.bennettavionics.com/kr86system.html)
Bob . . .
(http://www.matronics.com/Navigator?AeroElectric-List)
(http://www.matronics.com/contribution)
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Red Dot Digital SWR Meter |
At 08:02 PM 2/8/2012, you wrote:
>
>Bob,
>
>Thanks for the quick reply. One last question. After you power up
>the SWR Meter, do you transmit on the radio to get the readings or
>does it magically throw electrons about to get the readings?
No, this is a passive instrument. It reads your "forward"
and "reverse" power in watts. So it is both a test of your
transmitter's power output and a display of antenna/feedline
quality.
I'll run to the Post Office in the morning. I'm pretty certain
I have one waiting for me there.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: King KR-86 Loop Cable |
At 08:02 AM 2/9/2012, you wrote:
>
>
>Thanks Bob,
>
>
>I have the service manual, but there is no hint of what the
>capacitance or impedance is of the loop cables. It does show the
>cable as 2 separately shielded 2 conductor cables. The install
>manual gives 2 part numbers of cables (different lengths) and also
>says to not alter the length. One is 15 ft. and one is 24 ft.
Could you scan the radio's front end schematic
and share it?
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: King KR-86 Loop Cable |
At 08:02 AM 2/9/2012, you wrote:
>
>
>Thanks Bob,
>
>
>I have the service manual, but there is no hint of what the
>capacitance or impedance is of the loop cables. It does show the
>cable as 2 separately shielded 2 conductor cables. The install
>manual gives 2 part numbers of cables (different lengths) and also
>says to not alter the length. One is 15 ft. and one is 24 ft.
Yeah. I seem to recall a tid bit from the dark recesses
of history that the longer cable was the 'golden' device
and the shorter one had padding capacitors in the connector
to make up the difference between the two.
I don't think there were any off the shelf, low capacitance
cables made as twisted pairs. Those would be comparatively
huge bundles. When they went to an internal goniometer,
the loop became less critical . . . impedance matching
could be accomplished in the gonio-transformer.
Do you intend to fly this radio? What's the expected
distance from radio to loop? If it's relatively
short, say on the order of 6-10 feet, I think I'd
try plain vanilla shielded pairs and see what happens.
I don't know if I ever knew . . . is this radio among
the ranks of those where the long-wire sense antenna was
eliminated?
Given the wide frequency coverage (250-1700 KHz)
1:7 ratio, it seem unlikely that antenna features
and feedlines will be in any way resonant. It seems
more likely that special attention be paid to ratiometric
values of impedance and phase. So I'm guessing that
the feedlines for this radio need only be identical
as opposed to trimmed for resonance.
Bob . . .
________________________________________________________________________________
| From: | Hopperdhh(at)aol.com |
| Subject: | Re: King KR-86 Loop Cable |
Hi Bob,
Mainly I just want to learn more about ADF. I also have a 1946 Stinson
(besides the RV-7A) that I may install it in once its working just to see
what ADF navigation is like, but that is some time away.
Yes, I'll try some plain vanilla cable to start with. I think that 6 to
10 ft. would work in the Stinson. Two ft. would work on the bench here.
If one knew the value of the padding capacitor and the length of cable it
replaced, that would answer the question, wouldn't it?
There is a bench setup in the service manual that mentions a cable (pn
200-0440-00) with capacitance of 144 pF. (I found this after sending the
email below.) It also shows a sense cable (pn 200-0447-00) with the same
capacitance. The loop cable part number is not the same as in the installation
manual, though!!
There is mention of a King Service Memo -- SM75 -- in The Technicians
Notebook by Jerry Gordon.
www.aerostandard.com/images/TecnNote.pdf
He says, "Its a long drawn out procedure to determine the proper ADF sense
antenna configuration. What it boils down to is you need a capacitance
meter in your shop." I know we're talking about loop antennas here, but I'd
be interested to see SM75 if you have access to it.
I can scan the test setup page and the receiver front end. I don't think
attachments will work on this list. How do I share the scans. I can send
them as .pdf files.
Dan
In a message dated 2/9/2012 9:57:56 A.M. Eastern Standard Time,
nuckolls.bob(at)aeroelectric.com writes:
At 08:02 AM 2/9/2012, you wrote:
Thanks Bob,
I have the service manual, but there is no hint of what the capacitance or
impedance is of the loop cables. It does show the cable as 2 separately
shielded 2 conductor cables. The install manual gives 2 part numbers of
cables (different lengths) and also says to not alter the length. One is 15 ft.
and one is 24 ft.
Yeah. I seem to recall a tid bit from the dark recesses
of history that the longer cable was the 'golden' device
and the shorter one had padding capacitors in the connector
to make up the difference between the two.
I don't think there were any off the shelf, low capacitance
cables made as twisted pairs. Those would be comparatively
huge bundles. When they went to an internal goniometer,
the loop became less critical . . . impedance matching
could be accomplished in the gonio-transformer.
Do you intend to fly this radio? What's the expected
distance from radio to loop? If it's relatively
short, say on the order of 6-10 feet, I think I'd
try plain vanilla shielded pairs and see what happens.
I don't know if I ever knew . . . is this radio among
the ranks of those where the long-wire sense antenna was
eliminated?
Given the wide frequency coverage (250-1700 KHz)
1:7 ratio, it seem unlikely that antenna features
and feedlines will be in any way resonant. It seems
more likely that special attention be paid to ratiometric
values of impedance and phase. So I'm guessing that
the feedlines for this radio need only be identical
as opposed to trimmed for resonance.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | KT-76 Wire harness connectors. |
I have some 2 row x 12 slot x .156" pitch card
edge connectors with solder tabs. I believe this
fits the KT-76 transponder and several other
pieces of vintage avionics.
$3 each to interested parties . . .
Bob . . .
________________________________________________________________________________
| From: | Hopperdhh(at)aol.com |
| Subject: | Re: King KR-86 Loop Cable |
Bob,
I forgot to answer this question.
Bob asked:
I don't know if I ever knew . . . is this radio among
the ranks of those where the long-wire sense antenna was
eliminated?
Yes, sort of, but not in my case:
The loop antenna I have -- KA42 -- requires a separate "50 pF" sense
antenna. I see in the install manual that the radio is designed for 194 pF
sense antenna system -- 144 pF cable plus 50 pF antenna. It also refers to
Field Service Memo #75 which I would like to find.
The loop antenna KA42B has a built in sense antenna. It requires a
matching assembly (pn 200-02104-0000). The schematic for this assembly is shown
in the install manual. It feeds 8V to the antenna unit and uses 50 ohm
coax -- length not critical. Apparently there is an amplifier in the antenna
unit.
Dan
________________________________________________________________________________
| Subject: | Garmin 340A Acting Up |
I was out flying on Saturday and all of a sudden my Garmin 340A audio panel lit
up like a Christmas tree. All of the lights came on at once. I pressed Com1 and
Com3 buttons a few times and then everything went black.
Then I remembered that old adage about gas in the truck, sky above you and your
spare radio back in the car :)
Since it was snowing I turned back to the field and on the way back turned switches
on/off, pushed buttons to no avail and so on.
Back at the shop I checked the fuses (all good), re-seated the connections, turned
the ship's power on/off, cursed at it and so on. All efforts were in vain.
I then turned the ships power back on, turned the power switch on and pressed
the "Test" button.
With that all the marker lights went on. Releasing the test button extinguished
the lights and all was again dark.
Any thoughts? Has anyone seen this behavior before?
Up until Saturday the unit worked without issue.
Glenn
________________________________________________________________________________
| From: | James Robinson <jbr79r(at)yahoo.com> |
Hi Bob=0AI am trying to make a unit to disable a garage door type opener fo
r my hanger door.- It seems a switch that could be remotely activated to
disconnect the opener sensor line would be the simplest.- Your ideas?=0A
=0AJim=0A=0A-=0AJames Robinson=0AGlasair lll N79R=0ASpanish Fork UT U77
=0A=0A=0A________________________________=0A From: "Robert L. Nuckolls, III
" =0ATo: aeroelectric-list(at)matronics.com =0A
Sent: Thursday, February 9, 2012 9:10 AM=0ASubject: AeroElectric-List: KT-7
Robert L. Nuckolls, III" =0A=0AI have some 2
row x 12 slot x .156" pitch card=0Aedge connectors with solder tabs. I bel
ieve this=0Afits the KT-76 transponder and several other=0Apieces of vintag
e avionics.=0A=0A$3 each to interested parties . . .=0A=0A=0A=0A- Bob . .
====================
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Red Dot Digital SWR Meter |
The "Red Dot" SWR meter was waiting for me at the
Post Office this morning. I don't have a lot of sources
for significant power generation at VHF but here's
what I found.
When compared with some Bird wattmeters, the Red
Dot readings were in agreement to within 10% or
better at 130 MHz (1W hand held) and 146 Mhz
(5, 10 and 50W transceiver). The Red Dot pronounced
one of my loads as presenting a 1.2:1 SWR and
the forward 9W, reverse 0.08W readings were
consistent with calculations to produce
1.2:1 SWR.
Even with the 1W hand held, it was in direct
agreement with the Bird equipment at 0.9 watts
out.
When you power it up, it cycles between forward
power, reverse power and SWR. You can hit the button
to hold it in one of these three readings if you're
making adjustments.
Inside appearance is good. It even has multi-turn
trim pots and itty-bitty variable capacitors no
doubt useful for calibration (or re-calibration
in the future). The interior inspection revealed
the time honored pair of directional couplers
and their associated load/detector components.
The real value for this little guy probably
lies with the microprocessor driven display.
I have every reason to believe that the designers
use a processor not only for a/d and display
driver, I suspect their calculations take
low power detector non-linearities into
account as well. A 1W power level does not produce 1%
of the DC output as a 100W power level.
From what I've seen today, this instrument appears
to be a good value and MUCH more suited to VHF
measurement than most of the commercial-off-the-shelf
CB/HAM meters in circulation.
If you're contemplating acquisition of this
product, don't forget to order BNC-F to N-Male
adapters. You'll also want to fabricate a piece
of coax about 2' long with BNC connectors on
each end to let you insert the instrument into
your ship's transmission line.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 01:58 PM 2/9/2012, you wrote:
>Hi Bob
>I am trying to make a unit to disable a garage door type opener for
>my hanger door. It seems a switch that could be remotely activated
>to disconnect the opener sensor line would be the simplest. Your ideas?
How about adding a garage-door opener type radio remoted to
operate the hangar door and changing your exposed switch
to some kind of key-operated so that you can still have
wired access if the batteries run down in your remote?
Bob . . .
________________________________________________________________________________
| From: | Sam Marlow <sam.marlow(at)roadrunner.com> |
| Subject: | Re: Garmin 340A Acting Up |
Had a similar issue, but only involved the transmit 1 & 2 functions,
the transmitions were unreadable! It's still unresolved..............:-(
longg(at)pjm.com wrote:
> --> AeroElectric-List message posted by:
>
> I was out flying on Saturday and all of a sudden my Garmin 340A audio panel lit
up like a Christmas tree. All of the lights came on at once. I pressed Com1
and Com3 buttons a few times and then everything went black.
>
> Then I remembered that old adage about gas in the truck, sky above you and your
spare radio back in the car :)
>
> Since it was snowing I turned back to the field and on the way back turned switches
on/off, pushed buttons to no avail and so on.
>
> Back at the shop I checked the fuses (all good), re-seated the connections, turned
the ship's power on/off, cursed at it and so on. All efforts were in vain.
I then turned the ships power back on, turned the power switch on and pressed
the "Test" button.
>
> With that all the marker lights went on. Releasing the test button extinguished
the lights and all was again dark.
>
> Any thoughts? Has anyone seen this behavior before?
>
> Up until Saturday the unit worked without issue.
>
> Glenn
>
>
________________________________________________________________________________
| From: | "David Lloyd" <skywagon(at)charter.net> |
| Subject: | Re: Garmin 340A Acting Up |
Unless Garmin has changed their customer support attitude, I suggest giving
them a call and get a senior panel avionics tech guy on the phone. They
will work with you. And, it could turn out that they fix it for n/c.....
Dave
_________________________________________________________
----- Original Message -----
From: "Sam Marlow" <sam.marlow(at)roadrunner.com>
Sent: Thursday, February 09, 2012 4:27 PM
Subject: Re: AeroElectric-List: Garmin 340A Acting Up
>
>
> Had a similar issue, but only involved the transmit 1 & 2 functions, the
> transmitions were unreadable! It's still unresolved..............:-(
>
> longg(at)pjm.com wrote:
>> --> AeroElectric-List message posted by:
>>
>> I was out flying on Saturday and all of a sudden my Garmin 340A audio
>> panel lit up like a Christmas tree. All of the lights came on at once. I
>> pressed Com1 and Com3 buttons a few times and then everything went black.
>>
>> Then I remembered that old adage about gas in the truck, sky above you
>> and your spare radio back in the car :)
>>
>> Since it was snowing I turned back to the field and on the way back
>> turned switches on/off, pushed buttons to no avail and so on.
>>
>> Back at the shop I checked the fuses (all good), re-seated the
>> connections, turned the ship's power on/off, cursed at it and so on. All
>> efforts were in vain. I then turned the ships power back on, turned the
>> power switch on and pressed the "Test" button.
>>
>> With that all the marker lights went on. Releasing the test button
>> extinguished the lights and all was again dark.
>>
>> Any thoughts? Has anyone seen this behavior before?
>>
>> Up until Saturday the unit worked without issue.
>>
>> Glenn
>>
>>
>>
>>
>>
>>
>
>
>
________________________________________________________________________________
| Subject: | com antenna mounted |
| From: | "messydeer" <messydeer(at)yahoo.com> |
Hi!
Thought I'd post a followup from a few months ago when I was making my com antenna. See http://forums.matronics.com/viewtopic.php?t=85809 In short, it's a RadioShack CB antenna that I cut short. This allowed me to screw in the threaded post into the female-female coupler, which I threaded onto the UHF antenna connector I got off ebay, which is also shown in the original post. It came with a white plastic shoulder washer that insulates the antenna from the airframe. So far all this is on the outside.
On the inside is the other end of the UHF connector and a UHF to BNC adapter on
top of it (my antenna is belly mounted). I gave Bob the length needed for my
antenna cable and he made up an assembly with 90 BNC connectors on each end. This
is a really great deal, since I don't have crimping tools for this.
It was time to install it permanently today, so I took a couple pics and have posted
them below. You can also see a small 063 doubler I added. And in the outside
pic, the shoulder harness is dangling below the floor, making for a little
confusing pic.
--------
Dan
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=366007#366007
Attachments:
http://forums.matronics.com//files/com_antenna_outside_2_419.jpg
http://forums.matronics.com//files/com_antenna_inside_126.jpg
________________________________________________________________________________
| From: | "JOHN TIPTON" <jmtipton(at)btopenworld.com> |
| Subject: | Re: com antenna mounted |
Looks impressive: what (in the event of damage) would the down-time be to
build a replacement
John
----- Original Message -----
From: "messydeer" <messydeer(at)yahoo.com>
Sent: Friday, February 10, 2012 5:33 AM
Subject: AeroElectric-List: com antenna mounted
>
> Hi!
>
> Thought I'd post a followup from a few months ago when I was making my com
> antenna. See http://forums.matronics.com/viewtopic.php?t=85809 In short,
> it's a RadioShack CB antenna that I cut short. This allowed me to screw in
> the threaded post into the female-female coupler, which I threaded onto
> the UHF antenna connector I got off ebay, which is also shown in the
> original post. It came with a white plastic shoulder washer that insulates
> the antenna from the airframe. So far all this is on the outside.
>
> On the inside is the other end of the UHF connector and a UHF to BNC
> adapter on top of it (my antenna is belly mounted). I gave Bob the length
> needed for my antenna cable and he made up an assembly with 90 BNC
> connectors on each end. This is a really great deal, since I don't have
> crimping tools for this.
>
> It was time to install it permanently today, so I took a couple pics and
> have posted them below. You can also see a small 063 doubler I added. And
> in the outside pic, the shoulder harness is dangling below the floor,
> making for a little confusing pic.
>
> --------
> Dan
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=366007#366007
>
>
> Attachments:
>
> http://forums.matronics.com//files/com_antenna_outside_2_419.jpg
> http://forums.matronics.com//files/com_antenna_inside_126.jpg
>
>
>
________________________________________________________________________________
| Subject: | Re: com antenna mounted |
| From: | "messydeer" <messydeer(at)yahoo.com> |
Making the bent antenna means getting another CB antenna, cutting it to length,
heating and bending it. That takes easily less than an hour, even for me.
By far the longest part of the process was grinding down the antenna. It was something
like 0.20" at the tip, much fatter at the base. I had planned on just
leaving it like this, but got a little concerned about how much stiffer this would
make it, causing more damage if it hit something on the ground. Bob mentions
using 1/8" or 3/16" welding rod for this and I'd seen one other off the shelf
antenna that had a 0.15" diameter. I don't have a grinding wheel, so used
my HF belt/disc sander combo with 40-80 grit. Went through a couple pads, but
the antenna is much thinner, 0.125 at the tip and 0.20 at the base. The hardest
part of the grinding for me was dealing with the bend. Grinding it down before
bending would have made both the grinding and the bending easier.
--------
Dan
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=366030#366030
________________________________________________________________________________
| From: | Paul Millner <millner(at)me.com> |
| Subject: | A very wise woman... |
Apparently she knows where the real catches are! :-)
Paul
-------- Original Message --------
Subject: hello
Date: Fri, 10 Feb 2012 07:16:08 -0800 (PST)
From: mary morgan <dchuks27(at)yahoo.com>
hello,my name is Miss Mary,i saw your profile
on this (forums.matronics.com) and it really attracted me
a lot to drop you this few line of message
to know more about you.kindly contact
me through this email address
(marybaby332(at)yahoo.com) i wait for
reply
Mary
:)_____________
:)______$$$_______$$$
:)____$$$$$$$___$$$$$$$
:)___$$$$$$$$$_$$$$$$$$$
:)___$$$$$$$$$$$$$$$$$$$$$
:)____$$$$$$$$$:)$$$$$$$$$
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________________________________________________________________________________
| From: | Dan Jones <warbirds(at)shaw.ca> |
| Subject: | Switch Ratings Conversion (AC to DC) for ST23N Toggle |
Switches
Hi Bob,
I just finished reading your article "Switch Ratings, What's it all
Mean?" and Chapter 11 of THE BOOK but I can't quite decipher the data
for some switches I would like to use. I have some old (but mint
condition) ST23N switches salvaged from a DC-3 audio box that was almost
certainly a 28 volt airplane. I want to use them in a 14 volt Stearman
restoration. I like them because they have a nice heavy feel, they're
made in the USA, and they're from an era when people made stuff to work
and to last. They also look nice and "period". Gleaned off the
internet I have the switche's max rating of 250 VAC, and the contact
load current rating at max rated voltage of 2.0 amps inductive AC, and
5.0 amps resistive. My running of the numbers and adding a fudge factor
into it makes me think that 30 amps inductive and 75 amps resistive at
14 volts isn't out of line. Or am I talking out of my butt?
Dan
________________________________________________________________________________
| Subject: | Re: Switch Ratings Conversion (AC to DC) for ST23N |
Toggle Switch
| From: | "user9253" <fran4sew(at)banyanol.com> |
Many switch manufacturers rate the ampacity of their snap action switches at 125VAC
as equal to the ampacity at about 28VDC. My rule of thumb is that if a switch
can carry 5 amps at 125vac, then it can also carry 5 amps at 14vdc. If
a snap action switch can carry 5 amps at 250vac, then it should handle 10amps
OK at 14vdc. 75 amps resistive at 14 volts IS out of line. A switch will not
suddenly fail once its rating is exceeded. But the more it is overloaded, the
shorter is its life expectancy. More switches fail from corrosion due to non-use
than from being slightly overloaded.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=366136#366136
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Switch Ratings Conversion (AC to DC) for ST23N |
Toggle Switches
At 12:31 AM 2/12/2012, you wrote:
Hi Bob,
I just finished reading your article "Switch Ratings, What's it all
Mean?" and Chapter 11 of THE BOOK but I can't quite decipher the data
for some switches I would like to use. I have some old (but mint
condition) ST23N switches salvaged from a DC-3 audio box that was
almost certainly a 28 volt airplane. I want to use them in a 14 volt
Stearman restoration. I like them because they have a nice heavy
feel, they're made in the USA, and they're from an era when people
made stuff to work and to last. They also look nice and
"period". Gleaned off the internet I have the switche's max rating
of 250 VAC, and the contact load current rating at max rated voltage
of 2.0 amps inductive AC, and 5.0 amps resistive. My running of the
numbers and adding a fudge factor into it makes me think that 30 amps
inductive and 75 amps resistive at 14 volts isn't out of line. Or am
I talking out of my butt?
Study the data chart more closely and keep in mind that
a switch has THREE ratings: The ability to BREAK a circuit
(which is where the high voltage ratings come from) and
the ability to MAKE a circuit (which is the largest
influence on the high current ratings. Finally, there is
the ability to CARRY a current . . . which is generally
not a published rating because it is so heavily
influenced by ambient conditions and to some extent,
installation techniques. But in any case, the CARRY
current is not less than the max MAKE current.
Emacs!
I could not find detailed data on the switch number you
quoted . . . but the data I did find gives me the impression
that these are pretty much plain vanilla, two pole toggle
switches. If you got them out of an audio box, the likelihood
that they were tasked with handling a lot of current seems
unlikely.
You would be on safe ground stressing these switches to
the lightest of the categories in the data chart
(Electrical Code Rating of 2). There are few instances
where the switch needs to be much more robust.
How would you LIKE to use them? In any case, your
assumption that the current ratings are inversely
proportional to operating voltage is flawed. There
are numerous, interleaved influences on the SERVICE
LIFE of contacts be they in switches, relays or
contactors.
Bob . . .
________________________________________________________________________________
| From: | Dan Jones <warbirds(at)shaw.ca> |
| Subject: | Re: Switch Ratings Conversion (AC to DC) for ST23N |
Toggle Switches
________________________________________________________________________________
| Subject: | Impulse Coupled Mag/Elec Ignition Wiring |
| From: | Jerry Jerome <jjflyboy(at)gmail.com> |
Hi Bob,
I wired the electrical system on my RV3 per Z-11 and installed the two
S-700 toggle switches for the magnetos/starter. I recently discovered that
that my engine (O-320 D2J) has two impulse coupled magnetos, not one as I
thought initially, and they are both shot so I am considering replacing one
magneto and replacing the other with a LSE Plasma III electronic ignition.
Would it be be better to replace the one mag with an impulse coupled mag
rather than go to a non-impulse coupled one? If so, how would that system
be wired? I see Figure Z-27 shows how to wire up a non-impulse coupled mag
and one electronic ignition, but does not show the wiring if that mag were
impulsed coupled. Having one IC mag would allow me the advantage of
starting the engine on that mag should I lose the electronic ignition. I
could go to a full electronic system, but feel there is an advantage to
keeping one mag because of having the different failure modes. Also, not
sure if there is any difference in how an IC mag is driven by the engine
such that it could, if desired, be replaced by a non IC mag. The mags I
have now are both Slick 4251s with left hand rotation. Thanks
Jerry
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
| Subject: | Impulse Coupled Mag/Elec Ignition Wiring |
2/13/2012
Hello Jerry, You wrote:
1) "Would it be be better to replace the one mag with an impulse coupled mag
rather than go to a non-impulse coupled one?"
I think that it would be better not only for the reasons that you cite later
in your posting, but also easier since you would keep the same gearing and
magneto stack up that you have on your engine now.
2) "Also, not sure if there is any difference in how an IC mag is driven by
the engine
such that it could, if desired, be replaced by a non IC mag."
Yes, there is a difference. The IC mag drive arrangement is longer than the
drive arrangement on a non IC mag to allow space for the impulse coupleing
so there is an adapter required between the IC mag and the engine accessory
drive case for the IC mag that is not required for the non IC mag. Examine
your engine carefully and you will see this adapter (extension) between your
engine accessory drive case and the magnetos. That adapter is removed for
the non IC mag.
3) "......they are both shot so I am considering replacing one
magneto and replacing the other with a LSE Plasma III electronic ignition."
Have you considered going with a P mag for replacing one (or both) of your
present mags.
http://www.emagair.com/P-MAGII.htm
'OC' Baker Says: "The best investment we can make is the time and effort to
gather and understand knowledge."
=========================================================
Subject: AeroElectric-List: Impulse Coupled Mag/Elec Ignition Wiring
From: Jerry Jerome <jjflyboy(at)gmail.com>
Hi Bob,
I wired the electrical system on my RV3 per Z-11 and installed the two
S-700 toggle switches for the magnetos/starter. I recently discovered that
that my engine (O-320 D2J) has two impulse coupled magnetos, not one as I
thought initially, and they are both shot so I am considering replacing one
magneto and replacing the other with a LSE Plasma III electronic ignition.
Would it be be better to replace the one mag with an impulse coupled mag
rather than go to a non-impulse coupled one? If so, how would that system
be wired? I see Figure Z-27 shows how to wire up a non-impulse coupled mag
and one electronic ignition, but does not show the wiring if that mag were
impulsed coupled. Having one IC mag would allow me the advantage of
starting the engine on that mag should I lose the electronic ignition. I
could go to a full electronic system, but feel there is an advantage to
keeping one mag because of having the different failure modes. Also, not
sure if there is any difference in how an IC mag is driven by the engine
such that it could, if desired, be replaced by a non IC mag. The mags I
have now are both Slick 4251s with left hand rotation. Thanks
Jerry
________________________________________________________________________________
| From: | Charles Brame <chasb(at)satx.rr.com> |
| Subject: | Impulse Coupled Mag/Elec Ignition Wiring |
Jerry,
I'll let Bob and others address the wiring, but thought I'd throw in
my two cents on the mag/EI combination.
I have an 0-320 like you and I chose an impulse coupled Slick mag on
the left side, and a Jeff Rose ElectroAir EI system on the right. The
benefits are the hotter firing EI system in cruise, with a
conventional mag to get me home if the electrical system and/or the EI
fail. Additionally, an impulse coupled mag is necessary for starts
when the EI is not desirable or available. One gotcha, however. My
ElectroAir EI is susceptible to a low voltage situation, thus it
usually won't fire with the low voltage caused by the current draw
when my SkyTec starter is engaged. Of course, the EI tends to fire as
soon as the start switch is released with the possibility of a
kickback. I'm not sure if the same situation is true for other EI
systems, but it is something to check out. As recommended by Jeff
Rose, I start my engine with the impulse mag on and the EI off. It has
always started within the first couple of blades, hot or cold.
Charlie Brame
RV-6A N11CB
San Antonio
----------------------------------------------------------
> Subject: AeroElectric-List: Impulse Coupled Mag/Elec Ignition Wiring
> From: Jerry Jerome <jjflyboy(at)gmail.com>
>
> Hi Bob,
>
> I wired the electrical system on my RV3 per Z-11 and installed the two
> S-700 toggle switches for the magnetos/starter. I recently
> discovered that
> that my engine (O-320 D2J) has two impulse coupled magnetos, not one
> as I
> thought initially, and they are both shot so I am considering
> replacing one
> magneto and replacing the other with a LSE Plasma III electronic
> ignition.
> Would it be be better to replace the one mag with an impulse coupled
> mag
> rather than go to a non-impulse coupled one? If so, how would that
> system
> be wired? I see Figure Z-27 shows how to wire up a non-impulse
> coupled mag
> and one electronic ignition, but does not show the wiring if that
> mag were
> impulsed coupled. Having one IC mag would allow me the advantage of
> starting the engine on that mag should I lose the electronic
> ignition. I
> could go to a full electronic system, but feel there is an advantage
> to
> keeping one mag because of having the different failure modes.
> Also, not
> sure if there is any difference in how an IC mag is driven by the
> engine
> such that it could, if desired, be replaced by a non IC mag. The
> mags I
> have now are both Slick 4251s with left hand rotation. Thanks
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Impulse Coupled Mag/Elec Ignition Wiring |
At 02:40 PM 2/13/2012, you wrote:
Jerry,
I'll let Bob and others address the wiring, but thought I'd throw in
my two cents on the mag/EI combination.
I have an 0-320 like you and I chose an impulse coupled Slick mag on
the left side, and a Jeff Rose ElectroAir EI system on the right. The
benefits are the hotter firing EI system in cruise, with a
conventional mag to get me home if the electrical system and/or the
EI fail. Additionally, an impulse coupled mag is necessary for starts
when the EI is not desirable or available. One gotcha, however. My
ElectroAir EI is susceptible to a low voltage situation, thus it
usually won't fire with the low voltage caused by the current draw
when my SkyTec starter is engaged. Of course, the EI tends to fire as
soon as the start switch is released with the possibility of a
kickback. I'm not sure if the same situation is true for other EI
systems, but it is something to check out. As recommended by Jeff
Rose, I start my engine with the impulse mag on and the EI off. It
has always started within the first couple of blades, hot or cold.
I am pretty certain that modern incarnations
of the electronic ignition are not so afflicted.
Certainly a LSE system operates down to 6 volts
or so. Even if the system tends to start off on the
wrong foot during high inrush from a PM starter
motor, one can always separate the starter and
ignition power/up by a second or so. Starter inrush
is over in 100 milliseconds so if you hit the start
button and then power up the ignition after the first
blade passage, the system integration snafu can be
side-stepped. But I would sure want to analyze the
cranking system as well to make sure you're not
tossing away useful volts that could be recovered
by resizing or connection of wires.
If there are any working magnetos, then one
could certainly consider 'using them up' before
installing dual electronic ignition. Z-13/8 with
the ignition system driven by their own fuse from
the battery bus is pretty much bullet proof. One
could also consider the diode isolated, second
battery for the #2 ignition as described by LSE.
In any case, there are no compelling reasons to
use any magnetos except that you have a resource
that goes wasted if you take working mags off the
airplane.
Bob . . .
________________________________________________________________________________
| Subject: | Impulse Coupled Mag/Elec Ignition Wiring |
I have a Lightspeed/IM-Mag setup and start with both on. My airplane starts like
my car. That's suits me just fine. I've tried it both ways, mag only and IE
only. Both work fine. When the LSE starts it uses slightly more advanced timing.
I've never had kickback. If the fuel is flowing and the correct pressure is there,
it will fire. LSE or Slick or either or both. I've sat by while Cirrus and
Cessna sit there and crank, crank, crank. I never have such issues.
Same procedure for hot start except full throttle and mixture out until it fires.
Gotta be quick to get the throttle back. I normally run the boost pump a few
seconds to get the boiled gas out of the line first.
Lycoming IO-360.
Glenn
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Charles Brame
Sent: Monday, February 13, 2012 3:41 PM
Subject: AeroElectric-List: Impulse Coupled Mag/Elec Ignition Wiring
Jerry,
I'll let Bob and others address the wiring, but thought I'd throw in my two cents
on the mag/EI combination.
I have an 0-320 like you and I chose an impulse coupled Slick mag on the left side,
and a Jeff Rose ElectroAir EI system on the right. The benefits are the hotter
firing EI system in cruise, with a conventional mag to get me home if the
electrical system and/or the EI fail. Additionally, an impulse coupled mag is
necessary for starts when the EI is not desirable or available. One gotcha,
however. My ElectroAir EI is susceptible to a low voltage situation, thus it usually
won't fire with the low voltage caused by the current draw when my SkyTec
starter is engaged. Of course, the EI tends to fire as soon as the start switch
is released with the possibility of a kickback. I'm not sure if the same
situation is true for other EI systems, but it is something to check out. As recommended
by Jeff Rose, I start my engine with the impulse mag on and the EI
off. It has always started within the first couple of blades, hot or cold.
Charlie Brame
RV-6A N11CB
San Antonio
----------------------------------------------------------
> Subject: AeroElectric-List: Impulse Coupled Mag/Elec Ignition Wiring
> From: Jerry Jerome <jjflyboy(at)gmail.com>
>
> Hi Bob,
>
> I wired the electrical system on my RV3 per Z-11 and installed the two
> S-700 toggle switches for the magnetos/starter. I recently discovered
> that that my engine (O-320 D2J) has two impulse coupled magnetos, not
> one as I thought initially, and they are both shot so I am considering
> replacing one magneto and replacing the other with a LSE Plasma III
> electronic ignition.
> Would it be be better to replace the one mag with an impulse coupled
> mag rather than go to a non-impulse coupled one? If so, how would
> that system be wired? I see Figure Z-27 shows how to wire up a
> non-impulse coupled mag and one electronic ignition, but does not show
> the wiring if that mag were impulsed coupled. Having one IC mag would
> allow me the advantage of starting the engine on that mag should I
> lose the electronic ignition. I could go to a full electronic system,
> but feel there is an advantage to
> keeping one mag because of having the different failure modes.
> Also, not
> sure if there is any difference in how an IC mag is driven by the
> engine such that it could, if desired, be replaced by a non IC mag.
> The mags I have now are both Slick 4251s with left hand rotation.
> Thanks
________________________________________________________________________________
| Subject: | Looking for a used PC680 battery for testing |
| From: | "hotwheels" <jaybrinkmeyer(at)yahoo.com> |
I'm at the point of transitioning from a jury rigged power supply to "real" battery
in place for ground testing. Does anyone have one (or two!) used PC680s they'd
be willing to part with?
Also, I noticed that several types of terminal connectors can be used to connect
battery to wire (I have the B&C welding wires). There's are "L" Adapters, screw
on terminals, or bolts. What have others done in this regard?
Thanks,
Jay
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=366310#366310
________________________________________________________________________________
| Subject: | Re: Looking for a used PC680 battery for testing |
Hey Jay,
As far as connection goes, the PC 680's have a bolt (8mm if I recall) on
the top. I used a standard crimp-on battery lug from B&C and bolted both
the hot and the ground on. Pretty simple.
Regards,
Michael Wynn
RV 8 Finishing
San Ramon, CA
In a message dated 2/14/2012 3:09:46 P.M. Pacific Standard Time,
jaybrinkmeyer(at)yahoo.com writes:
--> AeroElectric-List message posted by: "hotwheels"
I'm at the point of transitioning from a jury rigged power supply to
"real" battery in place for ground testing. Does anyone have one (or two!) used
PC680s they'd be willing to part with?
Also, I noticed that several types of terminal connectors can be used to
connect battery to wire (I have the B&C welding wires). There's are "L"
Adapters, screw on terminals, or bolts. What have others done in this regard?
Thanks,
Jay
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=366310#366310
________________________________________________________________________________
| Subject: | Re: Thermocouple leads |
| From: | "natsuto" <smalleyexy(at)gmail.com> |
I have seen improper ground, cause all to read. Engine to ensure that the equipment
grounding, rather than the ground bus.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=366322#366322
________________________________________________________________________________
| Subject: | Re: Sign of the times |
| From: | "natsuto" <smalleyexy(at)gmail.com> |
I have a problem with the seller, and have a terrible time passed, even in the
customer service people get from PayPal is absolutely no help to solve my problem.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=366325#366325
________________________________________________________________________________
| Subject: | Re: Fuses instead of breakers |
| From: | "natsuto" <smalleyexy(at)GMAIL.COM> |
I promptly pull the hangar and wired directly to the battery Klaus's instructions.
I've always wanted, he wrote: There is a reason. Has been working ever since.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=366326#366326
________________________________________________________________________________
| Subject: | Re: Looking for a used PC680 battery for testing |
| From: | "hotwheels" <jaybrinkmeyer(at)yahoo.com> |
Thanks! Like most things in the build... It's obvious once you've done it once.
Jay
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=366349#366349
________________________________________________________________________________
| Subject: | Looking for a used PC680 battery for testing |
The PC680 comes with a 10mm bolt. Works well with standard B & C ends having a
5/16 or 3/8 hole. Sorry, mine is 4 years old but still works great. With a little
care, the PC680 has a great life span. If you intend to fly in the next 3
years, drop the $125.00 and enjoy a new 1.
Glenn
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of MLWynn(at)aol.com
Sent: Tuesday, February 14, 2012 7:20 PM
Subject: Re: AeroElectric-List: Looking for a used PC680 battery for testing
Hey Jay,
As far as connection goes, the PC 680's have a bolt (8mm if I recall) on the top.
I used a standard crimp-on battery lug from B&C and bolted both the hot and
the ground on. Pretty simple.
Regards,
Michael Wynn
RV 8 Finishing
San Ramon, CA
In a message dated 2/14/2012 3:09:46 P.M. Pacific Standard Time, jaybrinkmeyer(at)yahoo.com
writes:
--> AeroElectric-List message posted by: "hotwheels"
I'm at the point of transitioning from a jury rigged power supply to "real" battery
in place for ground testing. Does anyone have one (or two!) used PC680s
they'd be willing to part with?
Also, I noticed that several types of terminal connectors can be used to connect
battery to wire (I have the B&C welding wires). There's are "L"
Adapters, screw on terminals, or bolts. What have others done in this regard?
Thanks,
Jay
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=366310#366310
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Fuses instead of breakers |
At 08:03 PM 2/14/2012, you wrote:
>
>I promptly pull the hangar and wired directly to the battery Klaus's
>instructions. I've always wanted, he wrote: There is a reason. Has
>been working ever since.
When one is unsure of elegant alternatives
to common sense design goals, it is good to follow
the manufacturer's instructions.
At the same time, the manufacturer's instructions
my be only one of several recipes for success.
This is how the "experimental" airplane becomes
a teaching tool where new recipes can be considered
and proven. Just as the student in the chemistry
lab is learning by 'experiment' the teacher knows the
outcome of every lesson. For the teacher, the lab
is a tool to share recipes and the behavior of
their ingredients . . . anything but an experiment.
For the student, the experience morphs an experiment
into useful knowledge and skills. The next time that
recipe is repeated, the outcome is predictable.
At the same time, the teacher is ever mindful of
individual willingness to expand on their experimental
experiences. The explorer is well advised to temper
their quest for discovery with any admonition the
teacher may offer like, "Don't do that! You'll set
the lab on fire . . . or put your eye out!"
The word experimental is synonymous with explore
and discovery. But just as the automotive industry
is discovering that the lithium battery may not
yet be ready for prime time (perhaps influenced
by institutional pressure to 'hurry up and save
the planet'?) they have learned a lot and are still
in the discovery phase.
In experimental aviation we have a rich
library of historical successes (and failures)
to study. The trick is to shun any form of
pressure, be it institutional or from the hangar
mate next door. In experimental aviation we need
not "launch any new recipe into the sky before it's
time."
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Looking for a used PC680 battery for testing |
At 05:06 PM 2/14/2012, you wrote:
>
>I'm at the point of transitioning from a jury rigged power supply to
>"real" battery in place for ground testing. Does anyone have one (or
>two!) used PC680s they'd be willing to part with?
Consider too the acquisition of an "instant
power" or "jump-start" product from Wallmart
or perhaps Harbor Freight. I see devices in
both catalogs for $50 or less.
Emacs!
These products come with built in charger-
maintainers, a SVLA battery capable of cranking
an engine and handy soft cables that you can
cut shorter, apply terminals and bolt right
into your ship's system. So for not much more
than the cost of UPS to ship some used batteries
around the country, you can get a new battery
that is in a handy package, self maintaining,
convenient to attach to your airplane, and
convertible back to it's original purpose when
you're through stroking your airplane with it.
Bob . . .
________________________________________________________________________________
| From: | "John Loram" <johnl(at)loram.org> |
| Subject: | Looking for a used PC680 battery for testing |
Terrific idea! I'm headed off to Harbor Freight!
Thank you for your great generosity of time and thought, Bob.
-john-
_____
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Wednesday, February 15, 2012 6:48 AM
Subject: Re: AeroElectric-List: Looking for a used PC680 battery for testing
At 05:06 PM 2/14/2012, you wrote:
I'm at the point of transitioning from a jury rigged power supply to "real"
battery in place for ground testing. Does anyone have one (or two!) used
PC680s they'd be willing to part with?
Consider too the acquisition of an "instant
power" or "jump-start" product from Wallmart
or perhaps Harbor Freight. I see devices in
both catalogs for $50 or less.
Emacs!
These products come with built in charger-
maintainers, a SVLA battery capable of cranking
an engine and handy soft cables that you can
cut shorter, apply terminals and bolt right
into your ship's system. So for not much more
than the cost of UPS to ship some used batteries
around the country, you can get a new battery
that is in a handy package, self maintaining,
convenient to attach to your airplane, and
convertible back to it's original purpose when
you're through stroking your airplane with it.
Bob . . .
________________________________________________________________________________
| From: | "John Loram" <johnl(at)loram.org> |
| Subject: | MIT announces first free online course: 6.002x: Circuits |
and Electronics
Hey guys, here's your chance to test your chops!
<http://www2.electronicproducts.com/MIT_announces_first_free_online_course-a
rticle-fajb_free_MIT_course_feb2012-html.aspx>
http://www2.electronicproducts.com/MIT_announces_first_free_online_course-ar
ticle-fajb_free_MIT_course_feb2012-html.aspx
-john-
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Looking for a used PC680 battery for testing |
At 06:39 PM 2/15/2012, you wrote:
>Terrific idea! I'm headed off to Harbor Freight!
>
>Thank you for your great generosity of time and thought, Bob.
My pleasure sir. It was this List that kept me
enthusiastic about airplanes while the factory
where I worked was becoming more regulatory-
cookie-cutter than an institution of
creative-innovation.
Now that I'm retired and have no spare time,
the List is an excuse to 'unhook' from time-to-time
and keep the gray-matter from getting hide-bound.
I'm hoping to keep up a sufficient head of steam
to make credible introductions to aviation
electronics, and shop skills to my grandson.
He's only 4 so you guys need to keep stirr'n
this pot!
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | MIT announces first free online course |
At 06:43 PM 2/15/2012, you wrote:
>
>Hey guys, here's your chance to test your chops!
>
>
>http://www2.electronicproducts.com/MIT_announces_first_free_online_course-article-fajb_free_MIT_course_feb2012-html.aspx
>
Dr. Dee and I have been discussing this particular activity
along with some similar programs at other schools.
We've been sort of brain-storming the notion of
getting students in the communications arts to
produce some mini-lectures to be posted on Bethany's
website. The benefits are many including increased
exposure for the school, raising the competence
and comfort level of faculty in the use of new tools,
real-time, hands-on experience for the students who
produce the work, etc. etc.
They already offer some on-line courses on a fee
for credit basis. It might help build student
retention and graduation completion rates if
a constellation of core courses taken for free
could be converted to graduation credits AFTER
all other graduation requirements are met. Nothing
like getting the student more INVESTED in the outcome.
I've ordered some video capture equipment to tie a camera
to one of the computers. We'll be teaching ourselves
how to get some of Dr. Dee's classroom offerings on-line.
Hillsdale is offering a free, college level course on
the Constitution starting Feb 20. The lectures will be
archived so one may access them at their own convenience.
See: http://www.hillsdaleoffer.com/hillsdaleconstitution101
Nothing is more worthless than knowledge unshared. The
more you give it away, the greater value it acquires.
I think it was some guy named Pike who opined something
to the effect: "Things we do only for ourselves will
die with us; things we do for others or the community
can become immortal."
A few weeks ago I received an email from
http://www.best-aviation-sites.com/
who conferred a Top Aviation Website Award
on AeroElectric.com You folks gave direction to
on how that effort evolved and I thank you.
If any of you have the time, talent, hardware and
inclination to produce a "how to" video on any aspect
of OBAM aircraft construction, I would be pleased to
post it to AeroElectric.com
Pretty exciting stuff.
Bob . . .
________________________________________________________________________________
| From: | "Mike Creek" <mwcreek(at)frontiernet.net> |
| Subject: | Looking for a used PC680 battery for testing |
Bob,
I have two thoroughly abused PC680's complete with heat deformed jackets.
One reads 12.5 volts but the other is only at 8.25 volts. I'm at zip 89801
and can ship this Friday if you are interested in these derelicts.
Mike
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Wednesday, February 15, 2012 6:48 AM
Subject: Re: AeroElectric-List: Looking for a used PC680 battery for testing
At 05:06 PM 2/14/2012, you wrote:
I'm at the point of transitioning from a jury rigged power supply to "real"
battery in place for ground testing. Does anyone have one (or two!) used
PC680s they'd be willing to part with?
Consider too the acquisition of an "instant
power" or "jump-start" product from Wallmart
or perhaps Harbor Freight. I see devices in
both catalogs for $50 or less.
Emacs!
These products come with built in charger-
maintainers, a SVLA battery capable of cranking
an engine and handy soft cables that you can
cut shorter, apply terminals and bolt right
into your ship's system. So for not much more
than the cost of UPS to ship some used batteries
around the country, you can get a new battery
that is in a handy package, self maintaining,
convenient to attach to your airplane, and
convertible back to it's original purpose when
you're through stroking your airplane with it.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Looking for a used PC680 battery for testing |
| From: | Bill Watson <mauledriver(at)nc.rr.com> |
Reeeeeeecycle!
Sent from my iPad
On Feb 15, 2012, at 11:15 PM, "Mike Creek" wrote:
> Bob,
>
> I have two thoroughly abused PC680=99s complete with heat deformed j
ackets. One reads 12.5 volts but the other is only at 8.25 volts. I=99
m at zip 89801 and can ship this Friday if you are interested in these derel
icts.
>
> Mike
>
> From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelect
ric-list-server(at)matronics.com] On Behalf Of Robert L. Nuckolls, III
> Sent: Wednesday, February 15, 2012 6:48 AM
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: Looking for a used PC680 battery for testi
ng
>
> At 05:06 PM 2/14/2012, you wrote:
>
com>
>
> I'm at the point of transitioning from a jury rigged power supply to "real
" battery in place for ground testing. Does anyone have one (or two!) used P
C680s they'd be willing to part with?
>
> Consider too the acquisition of an "instant
> power" or "jump-start" product from Wallmart
> or perhaps Harbor Freight. I see devices in
> both catalogs for $50 or less.
>
>
>
> These products come with built in charger-
> maintainers, a SVLA battery capable of cranking
> an engine and handy soft cables that you can
> cut shorter, apply terminals and bolt right
> into your ship's system. So for not much more
> than the cost of UPS to ship some used batteries
> around the country, you can get a new battery
> that is in a handy package, self maintaining,
> convenient to attach to your airplane, and
> convertible back to it's original purpose when
> you're through stroking your airplane with it.
>
>
> Bob . . .
________________________________________________________________________________
| Subject: | Re: Looking for a used PC680 battery for testing |
| From: | Richard Girard <aslsa.rng(at)gmail.com> |
For what it's worth, I went to the Allpak battery store in Wichita just
last week for an 18 amp SLA battery. I bought a Powersonic with bolt
terminals for $44 plus tax. Which only goes to underscore that the HFT
package is a good deal, but if you just want a battery there are probably
local sources where you can get a new one for not much more than the
shipping cost or a used one.
Rick Girard
On Thu, Feb 16, 2012 at 7:36 AM, Bill Watson wrote:
> Reeeeeeecycle!
>
>
> Sent from my iPad
>
> On Feb 15, 2012, at 11:15 PM, "Mike Creek"
> wrote:
>
> Bob,****
>
> ** **
>
> I have two thoroughly abused PC680=92s complete with heat deformed jacket
s.
> One reads 12.5 volts but the other is only at 8.25 volts. I=92m at zip 8
9801
> and can ship this Friday if you are interested in these derelicts.****
>
> ** **
>
> Mike ****
>
> ** **
>
> *From:* owner-aeroelectric-list-server(at)matronics.com [mailto:
> owner-aeroelectric-list-server(at)matronics.com] *On Behalf Of *Robert L.
> Nuckolls, III
> *Sent:* Wednesday, February 15, 2012 6:48 AM
> *To:* aeroelectric-list(at)matronics.com
> *Subject:* Re: AeroElectric-List: Looking for a used PC680 battery for
> testing****
>
> ** **
>
> At 05:06 PM 2/14/2012, you wrote:
>
> ****
>
> jaybrinkmeyer(at)yahoo.com>
>
> I'm at the point of transitioning from a jury rigged power supply to
> "real" battery in place for ground testing. Does anyone have one (or two!
)
> used PC680s they'd be willing to part with?****
>
>
> Consider too the acquisition of an "instant
> power" or "jump-start" product from Wallmart
> or perhaps Harbor Freight. I see devices in
> both catalogs for $50 or less.
>
>
>
>
> These products come with built in charger-
> maintainers, a SVLA battery capable of cranking
> an engine and handy soft cables that you can
> cut shorter, apply terminals and bolt right
> into your ship's system. So for not much more
> than the cost of UPS to ship some used batteries
> around the country, you can get a new battery
> that is in a handy package, self maintaining,
> convenient to attach to your airplane, and
> convertible back to it's original purpose when
> you're through stroking your airplane with it.
>
>
> ****
>
> Bob . . .****
>
> *
>
===========
>
===========
===========
===========
>
> *
>
>
--
Zulu Delta
Mk IIIC
Thanks, Homer GBYM
It isn't necessary to have relatives in Kansas City in order to be unhappy.
- Groucho Marx
________________________________________________________________________________
| From: | Charles Brame <chasb(at)satx.rr.com> |
| Subject: | Looking for a used PC680 battery for testing |
I found a 17AH SVLA battery at a computer hardware store for about
$30. Its been running an electric gate for over five years with a
Battery Tender Junior charger. I have a friend that has been running a
similar computer store battery battery in a T-18 for several years.
Charlie Brame
RV-6A N11CB
San Antonio
________________________________________________________________________________
| From: | Etienne Phillips <etienne.phillips(at)gmail.com> |
Hi All
I=92m hoping that an RF greybeard will be able to offer some advice=85 I=92
ve
built an elevator trim system for my aeroplane, using an RC servo mounted
in the control surface, which is driven by a PIC18F microcontroller. This
has worked flawlessly for 2 years.
On the back of this success I built another identical one for a friend, and
due to the difference in installation which I=92ll explain shortly, I am
being plagued by a fault that I haven=92t been able to solve. The instigato
r
for this problem is the RF emitted by the COM antenna, which on my aircraft
is between the undercarriage (taildragger), and on the friends is inside
the vertical stabiliser. The design of the friend=92s antenna is as follows
:
The braiding of the coax is stretched out in one direction whist the core
is stretched out in the other. Since it=92s a fiberglass aeroplane, the
antenna is bonded to the skin of the vertical stab, without worry of
electrical problems.
The design of the trim system is as follows:
Ship=92s power is fed through a 7805 (with required smoothing caps) to the
18F4520, which generates the 1-2ms square pulse required by the servo. The
output of the PIC is protected by a polyswitch and zener diode combo,
resulting in a fairly low impedance output. Meanwhile, the power is fed
into an off-the-shelf RC power converter, which has a 6V, 15Amp capable
output. Signal and power is fed through a shielded 4-core tefzel wire to
the back of the aeroplane where it breaks out into the connections required
by the servo motor. The 6V power line is fed over two cores, whilst ground
is connected via one core and the shield.
The problem: when transmitting on the radio at the low end of the airband
spectrum 118Mhz, the servo goes bezerk. At 125MHz it twitches occasionally,
but is mostly usable.
I took an oscilloscope out to the aeroplane, and tested at points =93A=94,
=93B=94
and =93C=94 whilst both transmitting and not.
At =93A=94, the signal output by the PIC is clean, and unaffected by the no
ise
induced by transmission. The same signal is measured at =93B=94 whilst not
transmitting:
When transmitting, however, the signal at =93B=94 becomes completely degra
ded:
The amplitude of the noise is approximately 5Vp-p, superimposed on the
desired 5Vp-p signal. No wonder the servo doesn=92t know what=92s going on!
The power line is completely clean on both ends of the wire, at =93C=94 and
the
output to the power converter.
I am aware that the suitability of using an RC servo in a real aircraft is
a concern, but as has been proven in my aeroplane, mechanically and
aerodynamically the system works well, providing enough authority to trim
adequately without being so powerful that it cannot be over-ridden using
excessive force. The microcontroller code and electrical design of the
board has also proven to be reliable, and the installation in my aeroplane
has been robust and able to withstand the noise generated from the com
radio, although the distance to the antenna is much greater (not closer
than 2 meters). We both have the same radio, an MGL VHF-10.
In the knowledgeable opinions of those who have RF experience, will I be
able to implement a filter at the servo end of the wire to filter out the
120MHz-odd signal whilst retaining the integrity of the pulse? I tried
using a 1uF electrolytic cap as a filter (this was the only cap I had
on-hand, as the aeroplane is a 90min drive out of town), which had no
effect on the noise, and only degraded the underlying signal further. I
know that the cap isn=92t rated at high frequencies, so I only include it a
s
an anecdote. I=92m concerned about putting a ceramic cap in a EM field '
will
this not act as an antenna and make the problem worse?
Any advice would be appreciated!
Thanks,
Etienne
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Servo problem |
In the knowledgeable opinions of those who have
RF experience, will I be able to implement a
filter at the servo end of the wire to filter out
the 120MHz-odd signal whilst retaining the integrity of the pulse?
Absolutely. The variable position pulse is about a
half light-year away from the antagonistic signal . . .
well . . . maybe not light years but certainly separated
by many decades of RF spectrum separation.
We're talking sub killohertz versus 100 mHz or about
5 decades. A filter crafted to attenuate 100 mHz is
totally transparent to your signal-of-interest.
Based on your explorations and observations, it seems
likely that the RC servo is having problems with the
stronger RF field. RF, like all electro-magnetic
propagation attenuates based on the "square-law".
If you double the distance between emitting and
detecting devices, effects on the detector are
reduced to 1/4th of the original. That's a FAR FIELD
condition where there are no, distortions to the
field as it crosses the gap.
We know that the closer proximity of antenna
to servo can offer a profound increase in potential
interference. You also have NEAR-FIELD effects airplane
and wiring geometry. Far-field effects are only slightly
affected by frequency, near-field effects include
the effects of standing waves on airframe and wiring
which can be VERY sensitive to changes of frequency
for the antagonist signal. I can show you data
gathered in the hell-hole of a Hawker 800 were standing
waves generated by a poorly designed antenna system
would offer 1000:1 variations in interfering signal
while standing in one place and moving a probe around
within arm's reach. Further, the effects varied profoundly
from airplane to airplane.
I tried using a 1uF electrolytic cap as a
filter (this was the only cap I had on-hand, as
the aeroplane is a 90min drive out of town),
which had no effect on the noise, and only
degraded the underlying signal further. I know
that the cap isnt rated at high frequencies, so
I only include it as an anecdote. Im concerned
about putting a ceramic cap in a EM field will
this not act as an antenna and make the problem worse?
Ceramic capacitors are not counter-indicated
for this task. The few R/C servos I've played
with all had plastic cases and ZERO provisions
for managing electro-magnetic compatibility.
Without taking your servos to the lab and doing
the full DO-160 work-up, I cannot offer anything
like an elegant, optimized solution.
I will suggest some sledge-and-crowbar techniques
with a high probability of success.
I would "wrap" the servo in copper tape to craft
a metallic enclosure. I would fabricate two, pi-
section filters on the outside surface right where
the wires come out of the actuator. The actuator
ground would tie to the outside copper shell.
Two capacitors for each of the two filters would also
solder directly to the shell. The schematic would
look something like this.
http://tinyurl.com/6vekr2o
The actual parts values are exceedingly un-critical.
Components spanning perhaps 1000:1 ratios of
value would do the job without degrading the
command signal. The elegant components are
driven more by physical characteristics that
lend themselves to "spider-webbing" onto the
side of a thin walled, copper box.
If you could send me one of the servos along with
a picture of the installed servo showing where
the envelope could grow some warts without hitting
anything in the airplane, I can pretty quickly
accomplish the proposed modification. I would
take pictures of the process and provide a bill
of materials.
If the mod proves successful, I'll publish the
solution to the AEC website. If there's a demand
for these filters, we could do an etched circuit
board layout and fab a Mk II filter from surface
mount components. More elegant yet.
If you'd like to take a whack at a DIY solution,
I'd start with inductors on the order of 1 uHy
and capacitors on the order of 1000 pF. And yes,
they could be ceramic disks . . . just keep the
leads short.
By the way, ferrite beads on the wires are exceedingly
unlikely to fix this. Benefits of ferrites as
over-the-bundle solutions to EMC problems are exceedingly
over-rated. Any device destined to fly on a TC aircraft
would have run the DO-160 gauntlet and enjoys necessary
filters INSIDE. Any installation instructions that
call for external fixes or prophylactics to be added
as part of the installation process says the designer
has not done their homework.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Speaking of EMC filters |
I have received a couple of HID lamp kits for
evaluation with respect to EMC characteristics
in OBAM aircraft.
The first thing I did was order some HID conversions
for the high beams on my Sedona. Noises from these
lights are readily detectable while tuning around
on the AM radio.
The kit ballasts appear to have some sort of filter
in the harness between the ballast and lamp. However,
there is no such filter in the power input lead.
I've been side-tracked on a task for a customer but
I think I can get back on the bench next week. I'll
light one of these kits up on the bench and then
tune around with my DC-to-Light receiver. I can
get a rough idea of the fundamental excitation
frequency.
I'll take a whack at some filtering on the DC
input leads which goes to conducted noise. However,
if there is significant radiation from the output
leads and/or lamp, the problem is significantly
different.
I just learned today that I may be joining with NIAR
at WSU on some interesting endeavors. The folks I
used to work with at HBC in the EMC/EMI business
now work at NIAR with all new facilities and gear.
If the problem proves intractable using shade-tree
techniques, maybe I can get into the screen room and
secure a quick look-see with spectrum analyzer and probes.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Looking for a used PC680 battery for testing |
| From: | "hotwheels" <jaybrinkmeyer(at)yahoo.com> |
Thanks to all that replied to my query. I'm going to find something local that's
close enough.
Regards,
Jay
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=366467#366467
________________________________________________________________________________
| From: | David <ainut(at)knology.net> |
| Subject: | autopilot servos |
Guys, can you help guide me towards what the specs are for autopilot
motors? My idea is to use high-torque steppers so that they can be
computer controlled by software that I write in a computer that I design
(maybe an Arduino.) This is being done mostly for fun but also to be
safe and practical in my OBAM aircraft. How much torque do I need? The
Mustang II takes very, very small stick movement once airborne and the
faster you go, the less torque required. Basically, once airborne, you
weld your hand to your leg and just think about which direction you want
to go and that is enough to turn or climb.
I think it would be easiest, in programming, to have feedback from the
servo on it's current position and there are other methods but the
encoded type sounds easiest to implement. Thoughts?
Lastly, AIUI, most steppers become free-wheeling once power is removed
so that gives me control back instantly in event that is necessary
simply by turning them off, leaving no drag on the stick or ruddders.
I would like to control all 3 axes.
So which steppers and corresponding controllers do you guys recommend?
Or am I barking up the wrong tree?
Once fully debugged, I may play with automated take-off and landing but
that will be very, very closely watched if I ever get to that phase.
Too easy to break something important (like me!)
Thanks,
David M.
--
Tell the truth. Be honest. Be responsible to and for yourself.
We want our freedoms back. Strike the illegal legislations called: 1) obamacare,
2) "Patriot (HA!) Act", and 3) 'presidential orders' that affect anyone besides
gubmnt worker bees.
Hate crime laws? Really? Thought police? Orwell would be proud.
Every gram of cocaine you buy from elsewhere contributes to an innocent being murdered
in Central and South America. Grow your own or Stop taking it.
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: autopilot servos |
At 01:21 PM 2/17/2012, you wrote:
>
>Guys, can you help guide me towards what the specs are for autopilot
>motors? My idea is to use high-torque steppers so that they can be
>computer controlled by software that I write in a computer that I
>design (maybe an Arduino.) This is being done mostly for fun but
>also to be safe and practical in my OBAM aircraft. How much torque
>do I need? The Mustang II takes very, very small stick movement
>once airborne and the faster you go, the less torque
>required. Basically, once airborne, you weld your hand to your leg
>and just think about which direction you want to go and that is
>enough to turn or climb.
That's been the fondest wish of probably every a/p
designer since WWII. Guys like Ed King, Honeywell,
Bill Lear, Jim Younkin, et. als. can point to many
decades of development spanning dozens of recipes for
success.
>I think it would be easiest, in programming, to have feedback from
>the servo on it's current position and there are other methods but
>the encoded type sounds easiest to implement. Thoughts?
What have you read about autopilot history? Have you
studied any of the legacy design goals for failure
mode effects?
>Lastly, AIUI, most steppers become free-wheeling once power is
>removed so that gives me control back instantly in event that is
>necessary simply by turning them off, leaving no drag on the stick or ruddders.
Sort of. Steppers have a small but noticeable
"cogging" in back drive torque. Jim Younkin
went to stepper motors with a step down gearing
on the order of 10:1. Typical torque needed at
the aileron bell crank on an RV is 30 oz inches.
So the stepper would need to supply about 3 oz
inches of torque. At the same time, gearing magnifies
the backdriving forces for the de-energized motor.
10:1 is probably a golden goal for trading off physical
size of motor and tolerable back-drive forces.
Gene Brown and I discussed a stepper motor driven
a/p design probably 25 years ago at Electro-Mech.
It's the easiest to implement both mechanically
and electrically. No disconnect clutch needed.
Have you considered an RC servo driving a tab
on the surface to be controlled? RC servos are
cheap and easy to integrate. They need some 'help'
in the EMC department but that's doable.
Driving a tab keeps you totally disconnected
from primary flight surfaces and in absolute
control for over-ride forces needed to deal
with a tab that's jammed to the stop.
Most AUTOPILOTS are designed to do pretty much
everything a MANPILOT would do. But my idea of
an small-letters autopilot is to keep the airplane
pointed in the right direction with a minimum
of maneuvering . . . very light fingered touch
from the electronics.
This suggests that you don't need fat servos
capable of 2G loops and 360 degree per second
aileron roles.
>So which steppers and corresponding controllers do you guys recommend?
>Or am I barking up the wrong tree?
There's LOTS of trees to contemplate before you
start barking. Exactly what do you want this
product to do for you?
>Once fully debugged, I may play with automated take-off and landing
>but that will be very, very closely watched if I ever get to that phase.
>Too easy to break something important (like me!)
I can tell you that we had some VERY talented folks
working that problem on the AGATE program. There is
a Bonanza fitted with standard controls and 14v
hardware for the right seat and fly-by-wire, glass-
cockpit, highway-in-the-sky hardware in the left
seat that ran from a totally independent 28v
system. We installed our own SAAS (small aera
augmentation system) right on Beech Field to give
us real-time, centimeter correction for GPS signals.
I wont suggest that you can't do it . . . but I've
seen it done and the task is . . . shall we say
. . . monumental?
Your probability of success for any phase of
your endeavors begins with small goals with
stopping places for evaluation of results. Suggest
you start with a simple mod to one aileron to
add a tab, drive it with a servo that you can fit
into your aileron, then go fly it with manual
control knob on the servo. Can you achieve a servo/
tab combination that gives you the control authority
you need to be a precision wing-leveler/heading-hold
system in moderate turbulence? If the servo drives
to either stop, is the airplane manageable without
breaking a sweat?
Tame that dragon to the extent he's not trying to
eat you, then let's talk about ways to make him
heel on a leash . . . and ultimately tap-dance.
Bob . . .
________________________________________________________________________________
| From: | Peter Pengilly <peter(at)sportingaero.com> |
| Subject: | Re: autopilot servos |
David,
I admire your courage in taking on one of the more difficult challenges
in light aircraft avionics. An autopilot is primarily a flight
control/flight dynamics problem - if you know little of this subject
(for example if you are unfamiliar with stability derivatives) I would
urge you to read up on the subject or get help from someone who does.
There are also several non-intuitive gotchas that can sneak up on you.
Could I suggest you read the relevant chapter of FAR23 - I think it is
para 1329. I would suggest you ignore yaw until you have the other two
axes sorted (or perhaps for ever).
Servo torque must the the minimum that will do the job - as the pilot
must be able to over ride the servos and the autopilot must not be able
to break the aeroplane if it decides to inject full deflection elevator
(especially at max level speed). If possible I would measure the stick
force that is required to pull 2 g throughout the flight envelope, and
also the stick displacement. Then measure how much force and stick
displacement to roll at 30* per second. Now calculate the mechanical
advantage of the stick, and so the force the servo will have to exert at
the place you decide to connect it to the control system (make sure the
servo cannot under any circumstance go 'over centre'). I suspect you
will have to use some rate feedback, as well as position feedback, to
accurately apply the desired control surface angle. If you do not
include autotrim in pitch how will you tell the pilot that the servo is
about to become saturated so he can trim manually? How will you ensure
there are no large out of trim transients when the autopilot is disengaged?
You will find quite a change of displacement required from circuit speed
to fast cruise. CG position will also affect the stick force required.
The logic is also non-trivial, at what bank angles will you transition
from heading hold to bank angle hold? 5* is usual. You will also have to
decide which parameter to close on for altitude control. You only have
control over aircraft pitch attitude, so how do you use that to control
altitude? What will you control in the pitch axis if you aren't holding
altitude? Speed (IAS, TAS or ground speed) or rate of climb/descent?
Will you have a minimum speed that would won't let the airplane
decelerate below? For example, you are holding 5000ft and the engine
power slowly decreases (for whatever reason), at what point do you give
up trying to hold altitude and let the airplane descend at a minimum
airspeed - or will you hold altitude come what may and allow the
airplane to stall? If you are trying to follow a route, and for some
reason your are off the track line how will the autopilot regain track
and what information do you require from the nav system (GPS?) - draw
some pictures it will take me too long to type! For that matter, where
will get heading information for for heading hold, if from GPS what do
you do if the GPS quits? How will you tell the pilot that the autopilot
is no longer in control and he should start flying the airplane again?
Over powerful autopilots have the ability to break airplanes and kill
the crew, under powered servos will be no use at all. Best of luck with
your project, please keep us informed of how you progress.
Regards, Peter
As an example a military autopilot I worked on only controlled one
aileron through 2* (two degrees) and the elevator through about 15% of
max travel - you will need more but will not need to operate over the
full control surface travel.
On 17/02/2012 19:21, David wrote:
>
> Guys, can you help guide me towards what the specs are for autopilot
> motors? My idea is to use high-torque steppers so that they can be
> computer controlled by software that I write in a computer that I
> design (maybe an Arduino.) This is being done mostly for fun but also
> to be safe and practical in my OBAM aircraft. How much torque do I
> need? The Mustang II takes very, very small stick movement once
> airborne and the faster you go, the less torque required. Basically,
> once airborne, you weld your hand to your leg and just think about
> which direction you want to go and that is enough to turn or climb.
>
> I think it would be easiest, in programming, to have feedback from the
> servo on it's current position and there are other methods but the
> encoded type sounds easiest to implement. Thoughts?
>
> Lastly, AIUI, most steppers become free-wheeling once power is removed
> so that gives me control back instantly in event that is necessary
> simply by turning them off, leaving no drag on the stick or ruddders.
>
> I would like to control all 3 axes.
>
> So which steppers and corresponding controllers do you guys
> recommend? Or am I barking up the wrong tree?
>
> Once fully debugged, I may play with automated take-off and landing
> but that will be very, very closely watched if I ever get to that
> phase. Too easy to break something important (like me!)
>
> Thanks,
> David M.
>
________________________________________________________________________________
| Subject: | Exciting News from Aircrafters |
| From: | Timothy Farrell <motoracer(at)gmail.com> |
To all our dedicated customers and collegues,
Aircrafters has some significant and exciting news to announce. We have a
new partial owner! Tim Farrell has become a part of Aircrafters and will b
e assuming all of the administrative, sales, and marketing responsibilities
=2E Dave Saylor will be focusing his time and energy on the shop floor and w
orking on your airplanes.
I am originally from Oregon and have recently settled in the Monterrey Bay
area. I 'm an instrument rated private pilot with years of experience buil
ding Lancairs. I love experimental aviation and aviation in general. I h
ave experience teaching and I look forward to helping Aircrafters spread it
's knowledge about building and buying all kinds of experimental aircraft.
We look forward to having you back in our hanger. This year we will celebr
ate our 15 year anniversary, that makes us one of the oldest and most exper
ienced builder's assistance and experimental aircraft maintenance shops in
the world. Today we are still staffed 100% by A&P mechanics and Dave Saylo
r is our in house IA. We have a great relationship with the Sacramento FSD
O and always assure compliance with the FAA's 50% rule. We make sure that
every aspect of your build is quality, detailed and lasting.
As a new service, we are offering maintenance on Light Sport Aircraft, both
experimental and certified, along with Rotax service. Today's Light Sport
Aircraft utilize technology that is new to many shops, but old hand for us
=2E We have been working with composites, advanced avionics and glass panels
for over a decade, one reason that makes us the best shop around for LSAs.
Considering an RV-12? Give us a call.
Feel free to drop by or drop a line anytime, I can't wait to meet you in pe
rson,
Tim Farrell
Manager/Owner
Aircrafters
(831) 722-9141
motoracer(at)gmail.com
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Speaking of EMC filters |
At 09:34 PM 2/16/2012, you wrote:
I have received a couple of HID lamp kits for
evaluation with respect to EMC characteristics
in OBAM aircraft.
The first thing I did was order some HID conversions
for the high beams on my Sedona. Noises from these
lights are readily detectable while tuning around
on the AM radio.
The kit ballasts appear to have some sort of filter
in the harness between the ballast and lamp. However,
there is no such filter in the power input lead.
I've been side-tracked on a task for a customer but
I think I can get back on the bench next week. I'll
light one of these kits up on the bench and then
tune around with my DC-to-Light receiver. I can
get a rough idea of the fundamental excitation
frequency.
Saturday:
I did get a chance to fire up one of the HID
kits supplied for EMC evaluation.
On the bench, the light/ballast combination
produced very little noise in the killohertz
ranges (ADF, AM broadcast). Further, I could
not identify a fundamental frequency of
operation for the ballast in the short time
I was "searching". No doubt there is one
but it will take more diligence to identify.
What I did notice was that the system was a significant
BROADBAND noise source in the 100 MHz ranges.
This is not good. Broadband sources are generally
not electronic . . . they tend to be the result
of more chaotic behaviors like gazillions of
super-hot molecules crashing around in a
'glow tube'.
There is what appears to be an in-line filter
on the lead wires between ballast and lamp.
Given that it has to operate at voltage levels
in the thousands of volts, this is no trival
design job. Further, while one might THINK
that this filter is supplied to mitigate noise
from ballast electronics, it may well be that
its primary purpose is to reduce propagation
of noise from the lamp itself.
I've got to bug out for Wichita but I'll
be thinking about the next step for quantifying/
qualifying the problem.
Bob . . .
________________________________________________________________________________
| From: | Dave Saylor <dave.saylor.aircrafters(at)gmail.com> |
| Subject: | Re: Speaking of EMC filters |
I have one of the lamps you're evaluating in each wing tip. One tip has an
Archer comm antenna (for comm 2) and one has an Archer nav antenna. I hear
a big FZZZZT from comm 2 every time the lamp flashes, or continuously if
it's on steady. It seems constant throughout the frequency range. The nav
flags if the signal isn't very strong. I haven't experimented with it
enough to say any more than if I turn off the HID, the signal comes in and
vice versa.
I sure appreciate your help, Bob. Can't wait to hear what you find.
Dave Saylor
AirCrafters
140 Aviation Way
Watsonville, CA 95076
831-722-9141 Shop
831-750-0284 Cell
On Sat, Feb 18, 2012 at 10:00 AM, Robert L. Nuckolls, III <
nuckolls.bob(at)aeroelectric.com> wrote:
> nuckolls.bob(at)aeroelectric.com**>
>
> At 09:34 PM 2/16/2012, you wrote:
> nuckolls.bob(at)aeroelectric.com**>
>
> I have received a couple of HID lamp kits for
> evaluation with respect to EMC characteristics
> in OBAM aircraft.
>
> The first thing I did was order some HID conversions
> for the high beams on my Sedona. Noises from these
> lights are readily detectable while tuning around
> on the AM radio.
>
> The kit ballasts appear to have some sort of filter
> in the harness between the ballast and lamp. However,
> there is no such filter in the power input lead.
> I've been side-tracked on a task for a customer but
> I think I can get back on the bench next week. I'll
> light one of these kits up on the bench and then
> tune around with my DC-to-Light receiver. I can
> get a rough idea of the fundamental excitation
> frequency.
>
> Saturday:
>
> I did get a chance to fire up one of the HID
> kits supplied for EMC evaluation.
>
> On the bench, the light/ballast combination
> produced very little noise in the killohertz
> ranges (ADF, AM broadcast). Further, I could
> not identify a fundamental frequency of
> operation for the ballast in the short time
> I was "searching". No doubt there is one
> but it will take more diligence to identify.
>
> What I did notice was that the system was a significant
> BROADBAND noise source in the 100 MHz ranges.
> This is not good. Broadband sources are generally
> not electronic . . . they tend to be the result
> of more chaotic behaviors like gazillions of
> super-hot molecules crashing around in a
> 'glow tube'.
>
> There is what appears to be an in-line filter
> on the lead wires between ballast and lamp.
> Given that it has to operate at voltage levels
> in the thousands of volts, this is no trival
> design job. Further, while one might THINK
> that this filter is supplied to mitigate noise
> from ballast electronics, it may well be that
> its primary purpose is to reduce propagation
> of noise from the lamp itself.
>
> I've got to bug out for Wichita but I'll
> be thinking about the next step for quantifying/
> qualifying the problem.
>
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Speaking of EMC filters |
At 02:33 PM 2/18/2012, you wrote:
>I have one of the lamps you're evaluating in
>each wing tip. One tip has an Archer comm
>antenna (for comm 2) and one has an Archer nav
>antenna. I hear a big FZZZZT from comm 2 every
>time the lamp flashes, or continuously if it's
>on steady. It seems constant throughout the
>frequency range. The nav flags if the signal
>isn't very strong. I haven't experimented with
>it enough to say any more than if I turn off the
>HID, the signal comes in and vice versa.
>
>I sure appreciate your help, Bob. Can't wait to hear what you find.
Your findings are consistent with the theory
broad-band noise from the lamp's high energy
agitation of electrons on gas atoms.
Antenna proximity is going to be the elephant
in the room. I set my hand-held on one end of
a 7' bench from my signal generator which I
set up to produce an audible but noisy, modulated
signal. This would be roughly analogous to listening
to a weak station that is just above un-servicable.
I was carrying the HID around on a portable battery.
If I were 6' or more away from the hand held, I
could barely detect any influence of the HID
lamp on received signal.
From 3' away, the extra noise offered by the HID
lamp would have rendered the "remote station"
useless. Needless to say, an overwhelming
noise at those signal levels is not very
big. Indeed, probably insignificant to FM
radio reception in vehicles. I'll get some better
sense of the size of the problem when I get back
to M.L. on Monday.
In the mean time, can you hear the noise from a
hand held in the cockpit? Tune to open channel
and open the squelch. Turn the lamp on/off and
see if you can hear any change in the receiver's
normal background noise. Wearing headphones will
help.
Bob . . .
________________________________________________________________________________
| From: | Dave Saylor <dave.saylor.aircrafters(at)gmail.com> |
| Subject: | Re: Speaking of EMC filters |
I'll check with a handheld on Monday.
--Dave Saylor
In the mean time, can you hear the noise from a
> hand held in the cockpit?
>
________________________________________________________________________________
| Subject: | Re: autopilot servos |
| From: | "user9253" <fran4sew(at)banyanol.com> |
Here is a source of servos or linear actuators:
http://store.firgelli.com/
Here is an IC to control the speed of a motor or linear actuator:
http://www.mouser.com/Search/ProductDetail.aspx?qs=JaP0%252bruNJH%2F4ckdZw9AR1g%3D%3D
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=366552#366552
________________________________________________________________________________
| Subject: | Need Info on Vintage Landing Light |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
I came across a 19 pcs of Westinghouse Mazda 239W Aircraft Landing Lights (it actually
says Headlight..which dates it). I have 9 of the 24V bulbs and 10 of the
identical but12V bulbs. It appears that these are from the early 1930's since
they fit the (UK) Rearwin Cloudster for example.
How do I best sell these and to whom? What are 1930 landing lights worth? I can't
imagine there are more than a few of these on the planet.
eh?
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=366619#366619
Attachments:
http://forums.matronics.com//files/239w_mazda_544.jpg
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Need Info on Vintage Landing Light |
At 12:01 PM 2/19/2012, you wrote:
I came across a 19 pcs of Westinghouse Mazda 239W Aircraft Landing
Lights (it actually says Headlight..which dates it). I have 9 of the
24V bulbs and 10 of the identical but12V bulbs. It appears that these
are from the early 1930's since they fit the (UK) Rearwin Cloudster
for example.
How do I best sell these and to whom? What are 1930 landing lights
worth? I can't imagine there are more than a few of these on the planet.
These guys seem to think they're worth about $8 each . . .
http://bulbs.2yr.net/mazda-airplane.php
Bob . . .
________________________________________________________________________________
| Subject: | Re: Need Info on Vintage Landing Light |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
Bob,
$8 is what the guy paid for the one in his museum collection. It is not for sale.
There isn't another I can find anywhere.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=366634#366634
________________________________________________________________________________
| From: | Jeff Page <jpx(at)qenesis.com> |
| Subject: | Starter motor as generator |
A friend of mine asked me a question I didn't know the answer to.
If the starter contactor sticks on, I assume it would act like a
generator, and there would be a current path back to the bus.
Would the starter motor spin fast enough to generate a high enough
voltage to hurt anything ?
The overvoltage circuit would kick in and disconnect the alternator,
but that would do nothing to help.
Is an indication the starter contactor is engaged useful ? It still
wouldn't indicate if the bendix gear stuck, just the starter
contactor, so still not always an indicator.
Is there enough noise from the bendix gear and starter being overspun
by the engine to alert the pilot ?
Jeff Page
Dream Aircraft Tundra #10
________________________________________________________________________________
| From: | Bob McCallum <robert.mccallum2(at)sympatico.ca> |
| Subject: | Re: Need Info on Vintage Landing Light |
Eric;
Here's a guy specializing in locating and selling rare and obsolete light
bulbs. He lists your bulbs on his site but says he is sold out. He might be
an interested customer or perhaps give a hint as to the value.
http://tinyurl.com/8yykt4t
http://tinyurl.com/rqspa
Bob McC
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-
> server(at)matronics.com] On Behalf Of Eric M. Jones
> Sent: Sunday, February 19, 2012 3:40 PM
> To: aeroelectric-list(at)matronics.com
> Subject: AeroElectric-List: Re: Need Info on Vintage Landing Light
>
>
> Bob,
>
> $8 is what the guy paid for the one in his museum collection. It is not
for sale. There
> isn't another I can find anywhere.
>
> --------
> Eric M. Jones
> www.PerihelionDesign.com
> 113 Brentwood Drive
> Southbridge, MA 01550
> (508) 764-2072
> emjones(at)charter.net
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=366634#366634
>
>
>
>
>
>
>
> _-
> ====================================================
> ======
> _-
> ====================================================
> ======
> _-
> ====================================================
> ======
> _-
> ====================================================
> ======
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Starter motor as generator |
At 02:58 PM 2/19/2012, you wrote:
>
>A friend of mine asked me a question I didn't know the answer to.
>
>If the starter contactor sticks on, I assume it would act like a
>generator, and there would be a current path back to the bus.
No, all starters must be fitted with an over-running
disconnect clutch of some kind. Should a pinion gear
left solidly hooked to the starter's gearing it would
probably strip the armature pinion or spin windings
out of the armature slots
If it's a series wound starter, it will indeed spin
fast but because it is taking current out of the battery
an not because the engine is back-driving it. If you
browse through old patents on 'starter drives' you'll
an interesting array of de-clutching mechanisms designed
to prevent back driving. But as early as 1944 I found
the use of a 'sprag clutch' to prevent the starter from
being back-driven by the engine.
Figure 2 of http://www.freepatentsonline.com/2333765.pdf
http://en.wikipedia.org/wiki/Sprag_clutch
>Would the starter motor spin fast enough to generate a high enough
>voltage to hurt anything ?
A stuck starter is an unloaded motor, not a driven
generator.
>The overvoltage circuit would kick in and disconnect the alternator,
>but that would do nothing to help.
Moot point. Such a condition does not generate
an OV.
>Is an indication the starter contactor is engaged useful ? It still
>wouldn't indicate if the bendix gear stuck, just the starter
>contactor, so still not always an indicator.
Starter engagement disconnects are very simple mechanisms
but they're right up on the front of the engine to get
rained on, dusty, etc. If the pinion uses acceleration
inertia to engage it then it's a good candidate for
yearly tear down, cleaning and re-lubrication.
>Is there enough noise from the bendix gear and starter being overspun
>by the engine to alert the pilot ?
Maybe not. If your starter is a modern device
with a solenoid driven pinion gear engagement,
a stuck starter contactor is about the only
thing that can cause the pinion to hang in the
engaged position. I've hear of airshow pilots
flying hopped up airplanes suffering a hung
pinion and flew their routine with the pinion
spinning at a gazaillion rpm. Didn't heare
it before takeoff but had a starter and ring
gear replacement job to do on the ground.
Modern, low area, high pressure, intermittent
starter contactors energized with a robust
battery rarely hang. Further, these contactors
often have an "I" terminal which can be used to
driven a "starter energized" light.
http://www.aeroelectric.com/Pictures/Contactors/s702wire.jpg
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Starter motor as generator |
At 02:58 PM 2/19/2012, you wrote:
P.S. After sending the earlier reply I recalled the
origins of the OV legend. In airplanes with ammeters
(either minus-zero-plus battery ammeters =OR= an
alternator loadmeter), immediately after engine start
the ammeter would be hard-over feigning a strong effort
to 'recharge' the battery. In fact, the voltage regulator
was dumping current from alternator in response to
what it believed as a badly discharged battery. In
point of fact, the battery was fine but being heavily
loaded . . . perhaps to some value greater than alternator
output, by the free running starter motor.
This very high alternator output was mis-interpreted as
an OV event-in-progress as opposed to a misguided regulator
thinking it was being asked to recharge a dead battery.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Starter motor as generator |
| From: | Richard Girard <aslsa.rng(at)gmail.com> |
Right after high school I bought a 1959 Alfa Romeo Giulietta Spider.
Besides being a positive ground which made doing anything on the electrical
system a true PITA, it didn't have a spring return on the starter switch,
you had to physically turn the starter motor off. When I sold the car to my
best friend, I told him never to let anyone else drive the car. Two weeks
later he let his step brother drive it. Yep, he left the starter engaged
the entire time. The current flowing back through the system boiled the
battery and cooked the voltage regulator. It was only after he replaced
every major component in the starter generator system that he was able to
get the car to run right. Before that he went through three batteries. That
took most of the winter of 1971 and just a week after he got it running
again a car in front of him kicked up a stone that punctured the radiator.
The kid at the gas station ran cold water into the overheated engine which
caused the roof of the number three combustion chamber to crack right down
the center line of both valves and the spark plug. Dave was convinced the
car was cursed by then and sold it for $100. Forty years later he's still
one of my best friends, but that car nearly killed that, too.
Rick Girard
On Sun, Feb 19, 2012 at 2:58 PM, Jeff Page wrote:
>
> A friend of mine asked me a question I didn't know the answer to.
>
> If the starter contactor sticks on, I assume it would act like a
> generator, and there would be a current path back to the bus.
>
> Would the starter motor spin fast enough to generate a high enough voltage
> to hurt anything ?
>
> The overvoltage circuit would kick in and disconnect the alternator, but
> that would do nothing to help.
>
> Is an indication the starter contactor is engaged useful ? It still
> wouldn't indicate if the bendix gear stuck, just the starter contactor, so
> still not always an indicator.
>
> Is there enough noise from the bendix gear and starter being overspun by
> the engine to alert the pilot ?
>
> Jeff Page
> Dream Aircraft Tundra #10
>
>
--
Zulu Delta
Mk IIIC
Thanks, Homer GBYM
It isn't necessary to have relatives in Kansas City in order to be unhappy.
- Groucho Marx
________________________________________________________________________________
| Subject: | Re: Switch Ratings Conversion (AC to DC) for ST23N |
Toggle Swit
| From: | "stearman456" <warbirds(at)shaw.ca> |
Thanks, Bob. After rereading your article I see where my math went awry. It looks
like those switches will work out fine.
Dan
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=366679#366679
________________________________________________________________________________
| Subject: | Re: Need Info on Vintage Landing Light |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
Bob McC--Thanks, but if anyone can find stuff on the Interwebs, I can. So please
don't "Google it for me". The guy you refer to--not only does he have none,
but he will charge $$ to determine their value (Hah!) and will offer almost nothing.
I'll shoot him an email anyway, as well as post on the Cloudster sites.
But I have faith that somebody out there in Aeroelectricland knows what I need
to know.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=366705#366705
________________________________________________________________________________
| Subject: | Anyone have an ACK A-30 encoder? |
| From: | Janet Amtmann <jgamtmann2(at)GMAIL.COM> |
Does anyone have an ACK A-30-5 (or-9) encoder laying around that needs a
new home? The NOS A-30-2 that I just installed in my RV-6 turns out to be
defective and ACK will no longer service it. If I can relieve someone of
one languishing on a shelf after an upgrade, I would appreciate it. Name
your price.
Jurgen Amtmann
________________________________________________________________________________
| From: | Harley <harley(at)AgelessWings.com> |
| Subject: | Re: Anyone have an ACK A-30 encoder? |
Jurgen...I have a used one...not sure if it works or not...I was
told that it does.
If interested, let me know, I can send you pictures of it...I'll
send it to you for the cost of shipping, and if it works in your
application, pay me what it's worth to you...
It's label doesn't specify whether it's -5, -9 or any dash
number...any idea how to tell?
Harley Dixon
Long EZ N28EZ
Hangar 29 (D38)
Canandaigua, NY
-----------------------------------------------------------------
> Does anyone have an ACK A-30-5 (or-9) encoder laying around
> that needs a new home? The NOS A-30-2 that I just installed in
> my RV-6 turns out to be defective and ACK will no longer
> service it. If I can relieve someone of one languishing on a
> shelf after an upgrade, I would appreciate it. Name your price.
>
> Jurgen Amtmann >
> *
> *
________________________________________________________________________________
| Subject: | Re: Servo problem |
| From: | Etienne Phillips <etienne.phillips(at)gmail.com> |
Hi Bob
Thanks for the advice, and the solution! I installed a Pi filter only on
the signal line, but with components of 100pF and 10uH, as that's what was
available. The power line didn't seem to be affected by the noise, so I
decided to try just the signal line first, then add the power line filter
if required.
I also added a shield to the bottom of the servo using brass shimstock (I
figured it was almost the same as copper foil, but somewhat more available
- however not quite as solderable).
The soldering in the photo doesn't appear to have flowed and stuck
properly, but I gave it a good tug and it didn't come loose, so I just
attributed it to the brass. The filter is inside the heatshrink, well
supported from vibration.
The servo is a Turnigy HV-767 (http://www.hobbyking.com
/hobbyking/store/uh_viewItem.asp?idProduct=9983) - a 31kg.cm monster, but
is still the standard size, which makes it small enough to fit comfortably
in the elevator. The casing is aluminium, save for the plastic cap at the
bottom where all the electronics sits. At $60 a pop, it's a fairly cheap
alternative to the Ray Allen servo, and capable of being used for much more
than just trim.
The installation space is really tight, which meant that the filter had to
sit outside the cavity, which limited my options for shielding hence the
small strip over the bottom of the servo.
After adding the filter and the shielding, the signal going into the servo
is absolutely clean, without a shred of noise visible on the signal line.
The servo doesn't even notice the radio transmission now, so I'm very
relieved!
This is what the controller up front looks like:
There is also a stick-mounted rocker switch for easy trimming. The knob on
the face allows you to save a position (such as the take-off trim), and
return to it with a single click.
My current project is the autopilot side of this, which reads data in from
an Efis and does the required maths, sending the resulting trimmer position
to the trim controller over an RS-485 link (this is why I went for such big
servos). So far, altitude hold works, whilst bank and yaw are waiting to be
flight tested.
Thanks also for the offer of crafting a more elegant solution. Since the
filter is so simple to fabricate, and seems to work in this really abusive
environment, I wonder if it's even necessary=85? With plugs and attachments
it'll probably be unwieldy to install in such a small spot.
Once again, thanks!
Etienne
________________________________________________________________________________
| Subject: | Re: Servo problem |
| From: | "jonlaury" <jonlaury(at)impulse.net> |
Bob,
This sounds like a similar situation that I'm encountering with an EyeBeam that
uses capacitance for on/off and for dimming. It's housed in a small ceiling mounted
enclosure with my cabin speaker.
Everytime I key the mike, the EB flashes uncontrollably and the on/off and dimming
functions go inop. The only way to stop it is to pull the fuse.
Wishful thinking had me try ferrite clamps over the speaker wires or the EB twisted
pair shielded cable to no effect. But you knew that ;-).
Would the solution you devised for Etienne be germane to solving my problem?
Not sure how I would implement the copper shield as 1/2 of the EB is enclosed with
the speaker and 1/2 is exposed to the cabin.
Thanks,
John
I really like the EB and the small tidy console that houses the speaker so I hope
that I don't have to give it up to use a less EM/RF sensitive source of light.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=366804#366804
________________________________________________________________________________
| Subject: | Re: Servo problem |
| From: | Daniel Hooper <enginerdy(at)gmail.com> |
I'm sorry your ferrites didn't work.
Did you ever try to see if keying the mic without the comm radio on prevents the
issue?
On Feb 21, 2012, at 12:16 AM, jonlaury wrote:
>
> Bob,
> This sounds like a similar situation that I'm encountering with an EyeBeam that
uses capacitance for on/off and for dimming. It's housed in a small ceiling
mounted enclosure with my cabin speaker.
> Everytime I key the mike, the EB flashes uncontrollably and the on/off and dimming
functions go inop. The only way to stop it is to pull the fuse.
> Wishful thinking had me try ferrite clamps over the speaker wires or the EB twisted
pair shielded cable to no effect. But you knew that ;-).
>
> Would the solution you devised for Etienne be germane to solving my problem?
> Not sure how I would implement the copper shield as 1/2 of the EB is enclosed
with the speaker and 1/2 is exposed to the cabin.
>
> Thanks,
> John
>
> I really like the EB and the small tidy console that houses the speaker so I
hope that I don't have to give it up to use a less EM/RF sensitive source of light.
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=366804#366804
>
>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Servo problem |
At 12:16 AM 2/21/2012, you wrote:
>
>Bob,
>This sounds like a similar situation that I'm encountering with an
>EyeBeam that uses capacitance for on/off and for dimming. It's
>housed in a small ceiling mounted enclosure with my cabin speaker.
>Everytime I key the mike, the EB flashes uncontrollably and the
>on/off and dimming functions go inop. The only way to stop it is to
>pull the fuse.
>Wishful thinking had me try ferrite clamps over the speaker wires or
>the EB twisted pair shielded cable to no effect. But you knew that ;-).
>
>Would the solution you devised for Etienne be germane to solving my problem?
Probably not. Touch-buttons that sense body capacity
can be really twitchy in the presence of strong RF.
Can you send me a wiring diagram for your lighting
control system? I must admit that I'm not optimistic
but we can try. Need to see the installation manual
and wiring.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Servo problem |
| From: | "jonlaury" <jonlaury(at)impulse.net> |
Daniel,
No worries re the ferrites. It was easy and worth a shot. Thanks for trying. With
the com off there's no problem with the EB. There's a 15' parallel run of speaker
and EB wiring and that's where the problem is. When I run non-parallel
wiring to power the EB, the problem disappears. Soo...see below.
Bob,
Thank you for your willingness to give it a go, but I've decided that the simplest
fix is to re-route the wires to the EB. I didn't want to do that because it
means pulling out some nice upholstery work to get 2 x 22 ga wires underneath
it. But I know from experimentation that it will work.
That's going to be the best use of both yours and my time.;-)
Cheers,
John
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=366897#366897
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Servo problem |
At 11:36 AM 2/20/2012, you wrote:
Hi Bob
Thanks for the advice, and the solution! I
installed a Pi filter only on the signal line,
but with components of 100pF and 10uH, as that's
what was available. The power line didn't seem to
be affected by the noise, so I decided to try
just the signal line first, then add the power line filter if required.
Good show.
Thanks also for the offer of crafting a more
elegant solution. Since the filter is so simple
to fabricate, and seems to work in this really
abusive environment, I wonder if it's even
necessary? With plugs and attachments it'll
probably be unwieldy to install in such a small spot.
It wouldn't necessarily have any plugs, only
attach pads for wires. I envision an ECB perhaps
0.7" x 1.0" that would accommodate surface mount
components on one side leaving the other flat.
Holes in the corners would let you solder-thru
to attach the board directly to the outside copper
foil on the actuator while simultaneously grounding
the filter to the foil.
Wires would come off each end. They would, of course,
be strain relieved with adhesive or perhaps tied
down with another layer of copper tape over the whole
filter/wiring installation.
Pretty small and low profile.
In any case, it looks like your dragon has been
held at bay.
Bob . . .
________________________________________________________________________________
| From: | Marty Mason <captainmarty(at)bellsouth.net> |
I hope u like it http://www.markspeterson.com/message.php?Diane This really works!
________________________________________________________________________________
| From: | joe motis <joemotis(at)gmail.com> |
"Yippee" The five thousandth Lockheed P 38 built and painted in a stunning
vermillion orange. Nothing Canadian about it Built right here in sunny
SoCal.
On Wed, Feb 22, 2012 at 7:39 PM, Marty Mason wrote:
> captainmarty(at)bellsouth.net>
>
>
> I hope u like it http://www.markspeterson.com/message.php?Diane This
> really works!
>
>
________________________________________________________________________________
| From: | "Don" <dsvs(at)ca.rr.com> |
| Subject: | Com and Nav Radio and Antenna Questions |
-----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
Sent: Monday, February 06, 2012 6:21 PM
Subject: RE: AeroElectric-List: Com and Nav Radio and Antenna Questions
At 07:20 PM 2/5/2012, you wrote:
This will not break the bank, will purchase one. It does not mention
the ability to excite the feedline and antenna for setting up vor so
U will need help in doing that.
This is a self contained antenna analyzer. It features
a variable frequency oscillator that provides a test
signal source over a 2 to 170 Mhz range. There is a
counter that displays the oscillator's present frequency.
Finally, there is an array of detectors upon which a
ratiometric analysis is conducted to deduce the resistive
and reactive components of the antenna and display them.
Instruction manual can be found here:
http://www.mfjenterprises.com/pdffiles/MFJ-259B.pdf
While not a laboratory grade instrument, it's
a lot of bang for the buck.
The wingtip antenna you talk about in the connection is a slightly
modified Archer. Archer mounts them to the fiberglass wing tip and
sandwiches it between the glass and the wing root for the ground. I
am looking for the instructions that came with the unit and will send
them to you as soon as I find them.
Yeah, Bob was a little incensed when the folks
at Van's published dimensional details on his
first RV wingtip offerings (and I repeated them
in the 'Connection). Bottom line is that the antenna
is simply a gamma-matched monopole of which there
are many variations on a theme. The now arcane
'sled runner' marker beacon antennas on the belly
are a good example.
Once you have an MFJ259 in hand, you can both
trim overall length of the Archer design to
desired center frequency,
Shorter for higher center freq? If I need longer can I just rivet on an
extension?
you could also adjust
the gamma-match and tuning capacitor for optimum
performance too.
Is this done by just increasing or decreasing the plate size where the
center conductor attaches? Is this checked with the
Percent match function on the MFJ259B?
While this might be an intellectually satisfying
exercise (Hams can get downright pedantic in
their quest for the Holy-SWR), it would be hard
to observe much difference in performance between
an Archer cookie-cutter installation and one that
has be tuned to technical Nirvana.
I would like to be able to get one of these. To work in each wing
tip for my two vors. I have an APRS (2meter Jpole in one wingtip
that may make it impossible to get the Archer to work.
Why a j-pole? That's an awfully big antenna for
a line-of sight application. Why not the simple
vertical whisker?
I will ask the additional questions after I send you the Archer
instructions.
Got the data package. What's your question?
Bob . . .
________________________________________________________________________________
And did you intend to actually send a real link for us to enjoy?
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of joe motis
Sent: Wednesday, February 22, 2012 11:39 PM
Subject: Re: AeroElectric-List: Yippee!
"Yippee" The five thousandth Lockheed P 38 built and painted in a stunning vermillion
orange. Nothing Canadian about it Built right here in sunny SoCal.
On Wed, Feb 22, 2012 at 7:39 PM, Marty Mason wrote:
> captainmarty(at)bellsouth.net>
>
>
> I hope u like it http://www.markspeterson.com/message.php?Diane This
> really works!
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Com and Nav Radio and Antenna Questions |
>Once you have an MFJ259 in hand, you can both
>trim overall length of the Archer design to
>desired center frequency,
Shorter for higher center freq? If I need longer can I just rivet on an
extension?
Yes. But before you start tweaking the antenna,
Do a plot of SWR vs frequency over your range
of interest (108-118 MHz). If it's under 3:1
everywhere, the $time$ you spend on making
it better will probably not produce observable
increase in performance.
>you could also adjust
>the gamma-match and tuning capacitor for optimum
>performance too.
Is this done by just increasing or decreasing the plate size where the
center conductor attaches? Is this checked with the
Percent match function on the MFJ259B?
Yes. When I build this kind of antenna from
scratch, there are THREE adjustments. Over-all
LENGTH sets the center frequency. POSITION
of the gamma-match tap on the antenna sets
the impedance and VALUE of the capacitor
cancels the reactance of the gamma match
strut.
Bob no doubt did some experiments to finalize
these adjustments into a cookie-cutter antenna
without adjustments.
Degradation of performance due to proximity of
two antennas is not fully explored with an antenna
analyzer. The analyzer can only optimize the
antennas ability to accept energy from or deliver
energy to the feedline. You can hang a 50 ohm
resistor on the end of that feedline and produce
the appearance of a 'perfect' antenna while a
resistor has no useful qualities as an antenna.
A 'real' antenna will couple your feedline to the
'ether' but there are other variables that include
radiation patterns and radiation resistance that
probably have a more profound effect on performance
than just the SWR measurement.
It's REALLY hard to do comparative antenna work
on an airplane without a test range. Flying circles
in the sky while listening/talking to another facility
is useful but anecdotal . . . you can't plot comparative
data for two installations based on what you hear.
The bright star on the horizon is just that . . .
you're not going to talk to anyone over the horizon
no matter how good the antenna is. The energy
propagation needed to talk 150 miles is exceedingly
small . . . this means that an antenna can be a
very poor performer in terms of the best we know how
to do and still adequate to the task on our airplane.
This is more of an opportunity to broaden your own
been-there-done-that horizon than to fine-tune your
ship's proposed combination of antennas.
Bob . . .
________________________________________________________________________________
| From: | Dave Saylor <dave.saylor.aircrafters(at)gmail.com> |
| Subject: | Re: Speaking of EMC filters |
> In the mean time, can you hear the noise from a
> hand held in the cockpit? Tune to open channel
> and open the squelch. Turn the lamp on/off and
> see if you can hear any change in the receiver's
> normal background noise. Wearing headphones will
> help.
I can't hear the noise in the cockpit. I hear a very faint static
related to the lamps but not the objectionable loud noise I hear in
(the Archer antenna-ed) comm 2.
The slight noise seems constant until I move from the cockpit to
within about six feet of the lamp. Then it seems to increase a bit
with proximity but even close to the antenna it's not very loud.
However, if I put the handheld within a foot of the lamp, it breaks
squelch and makes the loud noise I'm trying to limit. With the
wig-wag on, the noise correlates perfectly to the lamp. It's
interesting, you can almost visualize the shape of the objectionable
area. The Archer antenna is within this noisy volume but it's size
requires the proximity.
If I leave the antenna in the wingtip, it has to be close to the lamp.
With some effort I could move the antenna. What are my options for
blocking the emissions? If I succeeded could I expect any remaining
antenna performance?
On a side note, the right lamp worked intermittently on the last
flight. Now it seems completely dead.
Dave Saylor
AirCrafters
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Speaking of EMC filters |
>I can't hear the noise in the cockpit. I hear a very faint static
>related to the lamps but not the objectionable loud noise I hear in
>(the Archer antenna-ed) comm 2.
>
>The slight noise seems constant until I move from the cockpit to
>within about six feet of the lamp. Then it seems to increase a bit
>with proximity but even close to the antenna it's not very loud.
>If I leave the antenna in the wingtip, it has to be close to the lamp.
> With some effort I could move the antenna. What are my options for
>blocking the emissions? If I succeeded could I expect any remaining
>antenna performance?
Hmmmm . . . no way to "block" without shielding
the lamp assembly. Doing this without diminishing
the value as a lamp is hard. Waayyyy back when
I was a Cessna when one of the strobe guys (I think
it was Whelen) sent us some hardware to play with.
Motor driven "light houses" under red domes were
the collision avoidance technology of choice.
The tubes emitted broadband noise heard as a 'pop'
in the radio. I remember Gordon Wood considering
some fine wire mesh to form a shield around the
flash tube assembly but 95% open to allow light
to pass.
I think they finally decided that the noise was
too small to be worried about . . . although
I've flown some rentals where the 'pop' was
definitely annoying.
Your story correlates with my experiments here.
I'm pretty sure it's radiation directly from the
gas filled tube. It may well be that your Archer
antenna is simply too close
>On a side note, the right lamp worked intermittently on the last
>flight. Now it seems completely dead.
Hopefully an isolated case. I'll scratch
around the 'net on HID EMC issues. I'll see
if anyone out at HBC has been looking into
it too. Doubtful. That once great airplane
company is sitting in the middle of the pond
on melting ice.
Bob . . .
>Dave Saylor
>AirCrafters
>
>
>-----
>No virus found in this message.
>Checked by AVG - www.avg.com
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
>
> > I hope u like it http://www.markspeterson.com/message.php?Diane This
> > really works!
My virus checker firewalled access to this site warning
that it contained some known issues with phishing and/
or malware.
Bob . . .
________________________________________________________________________________
| From: | "Martymason" <captainmarty(at)bellsouth.net> |
Sorry Everybody, This account was hacked again. I did not send this.
Marty
--------
Marty Mason
Europa XS Mono
10%
Norcross, GA
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=367092#367092
________________________________________________________________________________
| From: | "earl_schroeder(at)juno.com" <earl_schroeder(at)juno.com> |
---------- Original Message ----------
From: "Martymason" <captainmarty(at)bellsouth.net>
Subject: AeroElectric-List: Re: Yippee!
Date: Thu, 23 Feb 2012 12:50:43 -0800
Sorry Everybody, This account was hacked again. I did not send this.
Marty
--------
Marty Mason
Europa XS Mono
10%
Norcross, GA
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=367092#367092
I would advise anyone with an 'ATT; connected account like sbcglobal, bellsouth
etc to immediately change their logon information. Make the password long and
complicated and change it often. I suspect an inside person is responsible
for this hacking. You are the fifth person in the last 30 days to be infected
(that I am aware of) and all have been associated with ATT and/or Yahoo.
It is a pain and frustrating to undo the damage.. I was one of the five...
Earl
________________________________________________________________________________
| Subject: | Re: Servo problem |
| From: | "jonlaury" <jonlaury(at)impulse.net> |
Bob,
Before I go ripping into my headliner, I put the question to the Aveo engineers
about the interference that the EyeBeam was getting from somewhere.
They suggested this:
http://www.lineagepower.com/oem/pdf/FLT012A0Z.pdf
If you think this is the right track, does it go on the antagonist wiring or the
EB wiring?
Cheers,
John
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=367095#367095
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Servo problem |
At 04:25 PM 2/23/2012, you wrote:
>
>Bob,
>
>Before I go ripping into my headliner, I put the question to the
>Aveo engineers about the interference that the EyeBeam was getting
>from somewhere.
>They suggested this:
>
>http://www.lineagepower.com/oem/pdf/FLT012A0Z.pdf
>
>If you think this is the right track, does it go on the antagonist
>wiring or the EB wiring?
I looked up the product and found the wiring
diagrams. THAT filter is like killing fleas
with a 12 gauge . . .
How many of these devices are installed on your
airplane?
Bob . . .
________________________________________________________________________________
| Subject: | Re: Servo problem |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
Etienne drew a T-antenna on his discussion of the servo problem. This incluced
stripping back the insulation on a coax, separating the shield and core, and stretching
out each to form a Tee.
Clever. Actually too-clever-by-half. Would that it could be so easy! The problem
lies in the termination, since the core and shield do not share the signal.
In fact neither the core nor the shield even CARRY the signal.
See: periheliondesign.com/downloads/Dabbling%20with%20electricity.pdf
Then grab your SWR meter and Google any of the ham radio sites and see how to design
a T-antenna.
Might it work the way Etienne shows? A little probably, but let's do it right.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=367126#367126
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Dipole antenna fabrication |
At 09:39 AM 2/24/2012, you wrote:
Etienne drew a T-antenna on his discussion of the servo problem. This
incluced stripping back the insulation on a coax, separating the
shield and core, and stretching out each to form a Tee.
Clever. Actually too-clever-by-half. Would that it could be so easy!
The problem lies in the termination, since the core and shield do not
share the signal. In fact neither the core nor the shield even CARRY
the signal.
See: periheliondesign.com/downloads/Dabbling%20with%20electricity.pdf
Then grab your SWR meter and Google any of the ham radio sites and
see how to design a T-antenna.
Might it work the way Etienne shows? A little probably, but let's do it right.
Can you cite a website specific to the
fabrication of VHF dipoles fed with
coax?
Bob . . .
________________________________________________________________________________
| Subject: | Re: Dipole antenna fabrication |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
Bob,
I see that there are thousands of sites when you Google them. But here a general
purpose one that will get one started and discusses the issues (sorry for all
the equations...):
http://en.wikipedia.org/wiki/Dipole_antenna
But Bob, in your vast experience, have you seen many dipoles per Etienne's drawing?
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=367147#367147
________________________________________________________________________________
| Subject: | Re: Dipole antenna fabrication |
| From: | Dj Merrill <deej(at)deej.net> |
On 2/24/2012 1:44 PM, Eric M. Jones wrote:
> http://en.wikipedia.org/wiki/Dipole_antenna
>
> But Bob, in your vast experience, have you seen many dipoles per Etienne's drawing?
>
>
I'm not Bob, but his diagram looks like the one at the top right of
the page on that link you sent, and looks normal to me. I've made many
of these types of antennas for ham equipment when a quick-n-dirty setup
was needed. In fact, I just made one a couple of weeks ago for an APRS
setup. They tend to work okay. Not great, just okay. Much better than
the flexible antennas that come on a handheld radio.
What specifically are you seeing wrong with it?
-Dj
--
Dj Merrill - N1JOV
Sportsman 2+2 Builder #7118 N421DJ - http://deej.net/sportsman/
Glastar Flyer N866RH - http://deej.net/glastar/
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Dipole antenna fabrication |
At 12:44 PM 2/24/2012, you wrote:
Bob,
I see that there are thousands of sites when you Google them. But
here a general purpose one that will get one started and discusses
the issues (sorry for all the equations...):
http://en.wikipedia.org/wiki/Dipole_antenna
But Bob, in your vast experience, have you seen many dipoles per
Etienne's drawing?
Oh yeah . . . tens of thousands. For many years during
the vacuum tube days of aviation radio, tens of thousands
of single engine Cessna's went out the door with VOR whiskers
in the vertical fin cap that were nothing more sophisticated
than Etienne's coax fed dipole.
Granted, the whiskers were stuck out in the breeze and
assembled to the end of the coax but electrically, no
different. I think we had a brief romance with adding
BALUNS to these antennas. But without spending money
to do really scientific tests on the antenna range,
we generally relied on the anecdotal observations of
production and flight test pilots. Cessna was putting
10,000 airplanes a year out the door on 5 production
lines.
Some years later, Jim Weir suggested adding ferrite
toroidal cores the coax right at the junction with
the antenna. The idea was to reduce coax radiation
depicted in the Wikipedia article
Emacs!
. . . radiation caused by less than ideal termination
of the feedline. I tested this work-around in the EMC
lab at HBC about 15 years ago and found that an array
of 10 cores had no appreciable effect on these stray
shield currents.
Years later I suffered this "hot-d@#n" moment. I saw
an antenna product wherein the string of ferrites was
replace with a single ferrite core. The coax was
wound through it several times.
Emacs!
But of course! Inductance in a single magnetic circuit
varies with the SQUARE of turns. The picture seen here
has 6 passes of the coax through the core. It is the
electrical equivalent of 36 single cores. Now, having
'discovered' that, it would still be interesting to
go to the lab and see how effective it is.
Had we possessed the knowledge and materials to
duplicate this technique on a 1967 Cessna 172, I'll
bet the pilots would have continued to report "no
observable difference" in hearing the VORs.
Of course, transmit is a different story. Energy
levels are perhaps 130db higher (10 trillion
stronger). The effects of poorly terminated coax
don't have much to do with transmit/receive
performance but MIGHT have an impact on how
much energy is coupled into unwanted systems
radiated from coax feed lines bundled in with
other wires.
But then, the potential for interfering signals
radiated DIRECTLY from the antenna is already
very high on a small airplane. If it's a plastic
airplane, it's worse yet. And those 'el cheeso
vertical dipoles tend to be really popular for
installation in vertical fins of plastic airplanes.
Admittedly, these antennas are not the best we
know how to do . . . but they are easy to implement.
They pose some risks for EMC issues. But the
relative success with these installations suggests
that the ship's 'other' appliances are reasonably
designed immunity to strong external fields.
The genesis thread discovered that making the servo
more robust to the strong RFI environment was
a good solution. But given that it's a plastic
airplane, it's not clear that refining the
antenna's feed point design would have made any
difference at all.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Servo problem |
>
>http://www.lineagepower.com/oem/pdf/FLT012A0Z.pdf
>
>If you think this is the right track, does it go on the antagonist
>wiring or the EB wiring?
I looked up the product and found the wiring
diagrams. THAT filter is like killing fleas
with a 12 gauge . . .
How many of these devices are installed on your
airplane? How hard is it to remove them for
service/modification? If filtering the two
power lines is a solution to be explored, then
the filter components are quite small and
can be assembled right to the back of the
device were the wires emerge.
I'm disappointed but not surprised that the
folks who designed/built/marketed these
into aircraft did not fully appreciate
the potential for strong RF fields. Mobile
transmitters in vehicles of all kinds are
very strong locally . . . and they travel
around with the vehicle. You don't just
pass one occasionally.
In my earliest days of gainful employment
I worked for several two-way radio companies.
It was not uncommon to do installations of
transmitters having power outputs of 60
watts. Back then, the vehicle's other
systems were out of the copper-steel-
Bakelite (CSB) era. Exceedingly robust with
respect to RFI. In the silicon-software-
glass (SSG) era, virtually every active
component of a vehicles systems and accessories
is a potential victim for upset by local
radio energy fields.
Talk to the engineers that suggested the
boss-hog filters and see if they'll send
me a couple of these lights to play with.
If they would send a schematic of their
internals, it would be helpful too.
I'll craft a "scab-on" filter which they
can recommend for folks such as yourself
and consider for inclusion INSIDE future
production. You can encourage them to
contact me directly.
Barring their direct interest and response,
we can put the filters on your lights.
I suspect you could simply cut the lead wires
at the back of the dismounted units.
Leave me 1" pigtails. I'll send them
back with some sort of connector so
that you can re-install them in your
airplane.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Servo problem |
| From: | "jonlaury" <jonlaury(at)impulse.net> |
Bob,
I sent the following out this morning. Please let me know if they bite.
And thank you once AGAIN (and again, and again...!) for your generous offer to
craft a solution to the RF problem with the EyeBeam. Hearing from you that this
can be solved with an add-on filter, gives me confidence to go ahead and finally
install the structural belly panel (with its 60+ screws, and covering the
EB wiring) and move on to firing this thing up!
Cheers,
John
I regularly read, monitor and contribute to the Aerolectric List, which is monitored
by Bob Nuckolls, a long time consulting electrical engineer for Piper, Beech,
Cessna, Lear, Hawker, etc.
He is immensely generous and helpful to the experimental aircraft community in
designing electrical architectures for the large variety of experimental aircraft
and missions and enjoys solving challenging problems.
I submitted my RF problem with the EB and here is his response. I hope you will
take him up on his offer. The discussion started out because someone had an RF
problem with a servo, hence, "Post subject: Servo problem" I responded by asking
if the solution he crafted for the servo might be appropriate for the RF
problem with my EB.
Contact him directly here: http://www.aeroelectric.com/bob.nuckolls/
(Bob's response)
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=367234#367234
________________________________________________________________________________
| Subject: | Re: Dipole antenna fabrication |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
The Wiki site shows a simple dipole and the caption says:
"A schematic of a half-wave dipole antenna connected to an unbalanced coaxial cable.
Better practice is to connect the balanced dipole to the unbalanced line
with a balun."
I've been thinking of putting aluminum foil on the TV rabbit ears....
Proper termination is the key to antenna efficiency. If Cessna didn't do it, that
doesn't mean the homebuilder shouldn't do it right.
Bob et al. having flown extensively in the Western states and Mexico, I have plently
of experience with being a zillion miles from a station. At those times
I start to think that having a good radio and good antennas is a wise and cost
effective thing to do. But do what you want.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=367293#367293
________________________________________________________________________________
| From: | Richard Dudley <rhdudley1(at)bellsouth.net> |
| Subject: | Re: Dipole antenna fabrication |
A wise (and practical) person once said:
"Perfection is the enemy of good enough."
Anymouse
RHDudley
On 2/26/2012 12:41 PM, Eric M. Jones wrote:
> --> AeroElectric-List message posted by: "Eric M. Jones"
>
> The Wiki site shows a simple dipole and the caption says:
>
> "A schematic of a half-wave dipole antenna connected to an unbalanced coaxial
cable. Better practice is to connect the balanced dipole to the unbalanced line
with a balun."
>
> I've been thinking of putting aluminum foil on the TV rabbit ears....
>
> Proper termination is the key to antenna efficiency. If Cessna didn't do it,
that doesn't mean the homebuilder shouldn't do it right.
>
> Bob et al. having flown extensively in the Western states and Mexico, I have
plently of experience with being a zillion miles from a station. At those times
I start to think that having a good radio and good antennas is a wise and cost
effective thing to do. But do what you want.
>
> --------
> Eric M. Jones
> www.PerihelionDesign.com
> 113 Brentwood Drive
> Southbridge, MA 01550
> (508) 764-2072
> emjones(at)charter.net
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=367293#367293
>
>
________________________________________________________________________________
| Subject: | Re: Dipole antenna fabrication |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
A good job is sufficient. We disagree on what constitutes a good job.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=367298#367298
________________________________________________________________________________
| Subject: | Re: Dipole antenna fabrication |
| From: | Dj Merrill <deej(at)deej.net> |
On 2/26/2012 2:28 PM, Eric M. Jones wrote:
> --> AeroElectric-List message posted by: "Eric M. Jones"
>
> A good job is sufficient. We disagree on what constitutes a good job.
>
Having made and used at least a few dozen of these types of
antennas, I can say they generally do perform a "good job". They
perform far better than a handheld antenna, and perhaps not as good as
some other types of antennas, but overall they are okay, and of course,
cheap to make! :-) Comparing $$ spent to value received they rank very
high.
-Dj
--
Dj Merrill - N1JOV
Sportsman 2+2 Builder #7118 N421DJ - http://deej.net/sportsman/
Glastar Flyer N866RH - http://deej.net/glastar/
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Dipole antenna fabrication |
At 11:41 AM 2/26/2012, you wrote:
The Wiki site shows a simple dipole and the caption says:
"A schematic of a half-wave dipole antenna connected to an unbalanced
coaxial cable. Better practice is to connect the balanced dipole to
the unbalanced line with a balun."
. . . and I published instructions for adding this
feature to a coax fed dipole at
http://aeroelectric.com/articles/BALUN/Balun_Fabrication.html
. . . the same technique could be applied to a comm
dipole.
I've been thinking of putting aluminum foil on the TV rabbit ears....
Which will lower the resonant frequency of the antenna
and perhaps lower the Q . . . wider bandwidth. But
no benefit for relative efficiency compared to an "ideal"
dipole at the same frequency.
Proper termination is the key to antenna efficiency. If Cessna didn't
do it, that doesn't mean the homebuilder shouldn't do it right.
I can assure you that Dr. Wood read the same books
we've all read about antennas with professional
attendance to "better practice." The point I endeavored to
make was that after he came to understand all the
deleterious effects over which we had no control on
a C-172, adding baluns on the VOR antennas yielded very
small gains compared the sum of other losses.
Next time I can get into the test lab, I'll do some
measurements on the difference between a balun-fed
dipole and a bare foot, coax-fed dipole.
Bob et al. having flown extensively in the Western states and Mexico,
I have plently of experience with being a zillion miles from a
station. At those times I start to think that having a good radio and
good antennas is a wise and cost effective thing to do. But do what you want.
But you paint a picture suggesting that a balun would
make the difference between communicating with some distant
station . . . and not. Given the light of sight character
of VHF+ frequencies, you're more likely not to have a useable
path because you can't see the other station than because
your effective radiated signal is down by a few db due
to violations of feed point protocols. Further, it's
insufficient to be able to see the other station
peeking over the horizon (or mountaintop). The effects
of intervening "roughness" in the "Fresnel zone" can
have some profound effects on what might otherwise be
considered a free-space, line of sight situation.
http://web.arundale.co.uk/docs/ais/PathlossCalculationsforAmateurs.pdf
Mountain peaks and valleys intruding into the Fresnel
zone can kick your free space performance predictions
in the teeth.
Currents flowing on the coax shield are but part of
the 'violations' . . . the center impedance of a perfect
dipole is on the order of 73 ohms. This means that the
BEST SWR to be achieved without application of some
impedance matching is on the order of 73/50 = 1.46:1
So we've tossed off some efficiencies right out of the
box. When we plot radiation patterns on VHF antennas
on airplanes, one generally expects 10 db or greater
'lumpiness' in the pattern due to geometry of the
conductive elements around the antenna. So again,
if one is at 'extreme range' for useful communications,
it's more likely that you'll improve the path by turning
the airplane a few degrees as opposed to optimizing
feed point design.
Yes, a BALUN can be "better" but experience on small
aircraft has shown that the difference is so small
compared to all other effects combined that the balun
was not 'cost effective'. Further, it won't fix the
fundamental mis-match so 1.46:1 is still the best
we can expect. The textbooks are full of examples of
data taken from the idealized antenna and feed line
examined in the anechoic chamber with test equipment
that can split a DB into small pieces.
As soon as you put that same antenna is a real world
environment, lots of things with potential for
altering performance happen. This is why
the guy flying 'around with a radio capable of
talking to another one just like it 1000 miles
away finds that the practical limits are much
shorter for reasons mostly beyond control of
the antenna designer.
But just for grins, I've got some DIY antenna's I've
used in my weekend seminars and articles. I'll
fit one with a balun and leave the other barefoot.
Then see if my buddy Don P can tell the
difference without looking to see which one is
hooked up. Hmmmm . . . I think I know how to
do the experiment with equipment I have. Need
warmer weather though . . .
Bob . . .
________________________________________________________________________________
| From: | "Mike Wynn" <wynaire(at)citlink.net> |
| Subject: | Re: Dipole antenna fabrication |
Extremely educational dissection [of antenna logic] from bystander
viewpoint. Many thanks Bob.
Mike W.
Moab, UT
****************8's
----- Original Message -----
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com>
Sent: Sunday, February 26, 2012 9:35 PM
Subject: Re: AeroElectric-List: Re: Dipole antenna fabrication
>
>
> At 11:41 AM 2/26/2012, you wrote:
>
>
> The Wiki site shows a simple dipole and the caption says:
>
> "A schematic of a half-wave dipole antenna connected to an unbalanced
> coaxial cable. Better practice is to connect the balanced dipole to the
> unbalanced line with a balun."
>
> . . . and I published instructions for adding this
> feature to a coax fed dipole at
>
> http://aeroelectric.com/articles/BALUN/Balun_Fabrication.html
>
> . . . the same technique could be applied to a comm
> dipole.
>
> I've been thinking of putting aluminum foil on the TV rabbit ears....
>
> Which will lower the resonant frequency of the antenna
> and perhaps lower the Q . . . wider bandwidth. But
> no benefit for relative efficiency compared to an "ideal"
> dipole at the same frequency.
>
>
> Proper termination is the key to antenna efficiency. If Cessna didn't do
> it, that doesn't mean the homebuilder shouldn't do it right.
>
> I can assure you that Dr. Wood read the same books
> we've all read about antennas with professional
> attendance to "better practice." The point I endeavored to
> make was that after he came to understand all the
> deleterious effects over which we had no control on
> a C-172, adding baluns on the VOR antennas yielded very
> small gains compared the sum of other losses.
>
> Next time I can get into the test lab, I'll do some
> measurements on the difference between a balun-fed
> dipole and a bare foot, coax-fed dipole.
>
> Bob et al. having flown extensively in the Western states and Mexico, I
> have plently of experience with being a zillion miles from a station. At
> those times I start to think that having a good radio and good antennas is
> a wise and cost effective thing to do. But do what you want.
>
> But you paint a picture suggesting that a balun would
> make the difference between communicating with some distant
> station . . . and not. Given the light of sight character
> of VHF+ frequencies, you're more likely not to have a useable
> path because you can't see the other station than because
> your effective radiated signal is down by a few db due
> to violations of feed point protocols. Further, it's
> insufficient to be able to see the other station
> peeking over the horizon (or mountaintop). The effects
> of intervening "roughness" in the "Fresnel zone" can
> have some profound effects on what might otherwise be
> considered a free-space, line of sight situation.
>
> http://web.arundale.co.uk/docs/ais/PathlossCalculationsforAmateurs.pdf
>
> Mountain peaks and valleys intruding into the Fresnel
> zone can kick your free space performance predictions
> in the teeth.
>
> Currents flowing on the coax shield are but part of
> the 'violations' . . . the center impedance of a perfect
> dipole is on the order of 73 ohms. This means that the
> BEST SWR to be achieved without application of some
> impedance matching is on the order of 73/50 = 1.46:1
> So we've tossed off some efficiencies right out of the
> box. When we plot radiation patterns on VHF antennas
> on airplanes, one generally expects 10 db or greater
> 'lumpiness' in the pattern due to geometry of the
> conductive elements around the antenna. So again,
> if one is at 'extreme range' for useful communications,
> it's more likely that you'll improve the path by turning
> the airplane a few degrees as opposed to optimizing
> feed point design.
>
> Yes, a BALUN can be "better" but experience on small
> aircraft has shown that the difference is so small
> compared to all other effects combined that the balun
> was not 'cost effective'. Further, it won't fix the
> fundamental mis-match so 1.46:1 is still the best
> we can expect. The textbooks are full of examples of
> data taken from the idealized antenna and feed line
> examined in the anechoic chamber with test equipment
> that can split a DB into small pieces.
>
> As soon as you put that same antenna is a real world
> environment, lots of things with potential for
> altering performance happen. This is why
> the guy flying 'around with a radio capable of
> talking to another one just like it 1000 miles
> away finds that the practical limits are much
> shorter for reasons mostly beyond control of
> the antenna designer.
>
> But just for grins, I've got some DIY antenna's I've
> used in my weekend seminars and articles. I'll
> fit one with a balun and leave the other barefoot.
> Then see if my buddy Don P can tell the
> difference without looking to see which one is
> hooked up. Hmmmm . . . I think I know how to
> do the experiment with equipment I have. Need
> warmer weather though . . .
>
> Bob . . .
>
>
>
________________________________________________________________________________
| From: | Jan de Jong <jan_de_jong(at)casema.nl> |
| Subject: | Re: Dipole antenna fabrication |
Bob,
When you're at comparing I would be interested in the effectiveness of a
Pawsey stub balun as it is so easy to make from scrap coax.
The following antenna gets good results using such, apparently:
http://chrusion.com/BJ7/InvVeeAntenna4ULs.pdf
I also wonder about the effectiveness of a coax air coil in the feedline
(people use 10 turns of 2 or 3 " diameter or so). Also easy to make.
As I understand it the Pawsey stub works by compensating, the air coil
(and ferrites) by choking.
Jan de Jong
Robert L. Nuckolls, III wrote:
>
>
> At 11:41 AM 2/26/2012, you wrote:
>
>
> The Wiki site shows a simple dipole and the caption says:
>
> "A schematic of a half-wave dipole antenna connected to an unbalanced
> coaxial cable. Better practice is to connect the balanced dipole to
> the unbalanced line with a balun."
>
> . . . and I published instructions for adding this
> feature to a coax fed dipole at
>
> http://aeroelectric.com/articles/BALUN/Balun_Fabrication.html
>
> . . . the same technique could be applied to a comm
> dipole.
>
> I've been thinking of putting aluminum foil on the TV rabbit ears....
>
> Which will lower the resonant frequency of the antenna
> and perhaps lower the Q . . . wider bandwidth. But
> no benefit for relative efficiency compared to an "ideal"
> dipole at the same frequency.
>
>
> Proper termination is the key to antenna efficiency. If Cessna didn't
> do it, that doesn't mean the homebuilder shouldn't do it right.
>
> I can assure you that Dr. Wood read the same books
> we've all read about antennas with professional
> attendance to "better practice." The point I endeavored to
> make was that after he came to understand all the
> deleterious effects over which we had no control on
> a C-172, adding baluns on the VOR antennas yielded very
> small gains compared the sum of other losses.
>
> Next time I can get into the test lab, I'll do some
> measurements on the difference between a balun-fed
> dipole and a bare foot, coax-fed dipole.
>
> Bob et al. having flown extensively in the Western states and Mexico,
> I have plently of experience with being a zillion miles from a
> station. At those times I start to think that having a good radio and
> good antennas is a wise and cost effective thing to do. But do what
> you want.
>
> But you paint a picture suggesting that a balun would
> make the difference between communicating with some distant
> station . . . and not. Given the light of sight character
> of VHF+ frequencies, you're more likely not to have a useable
> path because you can't see the other station than because
> your effective radiated signal is down by a few db due
> to violations of feed point protocols. Further, it's
> insufficient to be able to see the other station
> peeking over the horizon (or mountaintop). The effects
> of intervening "roughness" in the "Fresnel zone" can
> have some profound effects on what might otherwise be
> considered a free-space, line of sight situation.
>
> http://web.arundale.co.uk/docs/ais/PathlossCalculationsforAmateurs.pdf
>
> Mountain peaks and valleys intruding into the Fresnel
> zone can kick your free space performance predictions
> in the teeth.
>
> Currents flowing on the coax shield are but part of
> the 'violations' . . . the center impedance of a perfect
> dipole is on the order of 73 ohms. This means that the
> BEST SWR to be achieved without application of some
> impedance matching is on the order of 73/50 = 1.46:1
> So we've tossed off some efficiencies right out of the
> box. When we plot radiation patterns on VHF antennas
> on airplanes, one generally expects 10 db or greater
> 'lumpiness' in the pattern due to geometry of the
> conductive elements around the antenna. So again,
> if one is at 'extreme range' for useful communications,
> it's more likely that you'll improve the path by turning
> the airplane a few degrees as opposed to optimizing
> feed point design.
>
> Yes, a BALUN can be "better" but experience on small
> aircraft has shown that the difference is so small
> compared to all other effects combined that the balun
> was not 'cost effective'. Further, it won't fix the
> fundamental mis-match so 1.46:1 is still the best
> we can expect. The textbooks are full of examples of
> data taken from the idealized antenna and feed line
> examined in the anechoic chamber with test equipment
> that can split a DB into small pieces.
>
> As soon as you put that same antenna is a real world
> environment, lots of things with potential for
> altering performance happen. This is why
> the guy flying 'around with a radio capable of
> talking to another one just like it 1000 miles
> away finds that the practical limits are much
> shorter for reasons mostly beyond control of
> the antenna designer.
>
> But just for grins, I've got some DIY antenna's I've
> used in my weekend seminars and articles. I'll
> fit one with a balun and leave the other barefoot.
> Then see if my buddy Don P can tell the
> difference without looking to see which one is
> hooked up. Hmmmm . . . I think I know how to
> do the experiment with equipment I have. Need
> warmer weather though . . .
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | Jan de Jong <jan_de_jong(at)casema.nl> |
| Subject: | Re: Dipole antenna fabrication |
Bob,
Sorry about this. The balun you describe making IS a Pawsey stub -
should have taken a look before responding.
In any case - I'm interested in the comparison.
Jan
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Dipole antenna fabrication |
At 05:12 AM 2/27/2012, you wrote:
>
>Bob,
>
>Sorry about this. The balun you describe making IS a Pawsey stub -
>should have taken a look before responding.
>In any case - I'm interested in the comparison.
You are correct. If one compares the Pawsey stub with a
1/4 wave, de-coupling sleeve or "sleeve balun" as shown in Wikipedia:
Emacs!
. . . we see that the top end of the sleeve is the open end
of a shorted 1/4-wave transmission line. I.e., the
impedance of the top rim of the sleeve looking at the
shorted end is very high. Hence, connecting it to the
center conductor adds no 'load' to purposeful energy
but it would have the effect of collecting differential
currents between coax shield and the center conductor
and force them toward equivalency.
The Pawsey stub functions in the same manner except that
its behavior is more like a short piece of balanced
transmission line as opposed to a piece of coax. This
brings to light an error in my balun article cited
earlier. Since the stub IS NOT operating as a free-space
1/4-wave but instead as a transmission line, dielectric
effects on velocity come into play. The velocity factor
of this piece of transmission line is on the order of
.95 to .97 which means that my 26" dimension for the
stub would be closer to optimum were it shortened by
an inch or so.
The 'coiled coax ploy" has good foundations
in physics. Consider this image from the Wikipedia
article:
Emacs!
The current balun is a common mode choke which
may be implemented by wires on a high-efficiency
core (as in many TV couplers), a coil of coax
immediately adjacent to the attach point on the
dipole or consider this image also from Wikipedia
article on baluns:
Emacs!
As you can see here, the common mode choke effects
are greatly enhanced by winding the coax onto
the core. Inductance in these windings is proportional
to the permeability of the magnetic path material.
Air is 1.0, the ferrite may be 5-20 . . . thus
multiplying the beneficial effects by that factor.
The neat thing about this balun is that it is not
resonant or tuned; thus effective over a wider range
of frequencies. The stubs in coax or balanced transmission
lines are tuned and optimum at one frequency only.
The 'hard' thing about the coax on core ploy is finding
coax that will wind tightly through a relatively
small core WITHOUT dropping below the recommended
bend radius for that coax. Coaxes with solid center
conductors are at risk for center conductor migration
through the insulation over time and temperature
cycles. RG-141 wound through a core like that has
potential for becoming a shorted feed line years from
now. The commercial antenna I saw with this technique
used a small diameter, very flexible coax and offered
a BNC connector on the stub for extending the feed line
to the appliance with more conventional coax.
Bob . . .
________________________________________________________________________________
| From: | Jan de Jong <jan_de_jong(at)casema.nl> |
| Subject: | Re: Dipole antenna fabrication |
Bob, thank you for the explanation.
There was some discussion on the web whether the velocity factor to be
used for finding the length of the Pawsey stub was that for the coax
insides (NO) or the coax outsides (YES). The latter would be the .97 to
.99 then.
Jan
________________________________________________________________________________
| From: | "Noel Loveys" <noelloveys(at)yahoo.ca> |
| Subject: | Re: Dipole antenna fabrication |
Dipole antenna erected vertically is similar to the 1/4 wave whip that we
now use. The tricks are to make sure you have a large enough groundplane
(section of the aircraft skin). When I first saw the talk of dipole
antennae I assumed incorrectly you wanted to be able to remove a radio and
take it with you and still have good range in case of a crash.
Aircraft radios are restricted to power. Basically the powers to be don't
want you to be transmitting thousands of miles otherwise they would up the
power of transceivers and drop the frequency closer to six meters than to
two meters. Main problem with that is you could end up with a lot of
crosstalk like they used to have on the CB band (11 meters).
While flying in mountainous areas for safety I would not be without the new
400 mHz ELT. There are lots of things about those ELTs I don't like but we
are stuck with it.
Noel
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Eric M.
Jones
Sent: February 26, 2012 2:12 PM
Subject: AeroElectric-List: Re: Dipole antenna fabrication
The Wiki site shows a simple dipole and the caption says:
"A schematic of a half-wave dipole antenna connected to an unbalanced
coaxial cable. Better practice is to connect the balanced dipole to the
unbalanced line with a balun."
I've been thinking of putting aluminum foil on the TV rabbit ears....
Proper termination is the key to antenna efficiency. If Cessna didn't do it,
that doesn't mean the homebuilder shouldn't do it right.
Bob et al. having flown extensively in the Western states and Mexico, I have
plently of experience with being a zillion miles from a station. At those
times I start to think that having a good radio and good antennas is a wise
and cost effective thing to do. But do what you want.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=367293#367293
________________________________________________________________________________
| From: | "Noel Loveys" <noelloveys(at)yahoo.ca> |
| Subject: | Re: Dipole antenna fabrication |
"Good enough" is everyone's enemy when it comes to ceasing to operate at
3000' !
Noel
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Richard
Dudley
Sent: February 26, 2012 3:06 PM
Subject: Re: AeroElectric-List: Re: Dipole antenna fabrication
A wise (and practical) person once said:
"Perfection is the enemy of good enough."
Anymouse
RHDudley
On 2/26/2012 12:41 PM, Eric M. Jones wrote:
> --> AeroElectric-List message posted by: "Eric M.
Jones"
>
> The Wiki site shows a simple dipole and the caption says:
>
> "A schematic of a half-wave dipole antenna connected to an unbalanced
coaxial cable. Better practice is to connect the balanced dipole to the
unbalanced line with a balun."
>
> I've been thinking of putting aluminum foil on the TV rabbit ears....
>
> Proper termination is the key to antenna efficiency. If Cessna didn't do
it, that doesn't mean the homebuilder shouldn't do it right.
>
> Bob et al. having flown extensively in the Western states and Mexico, I
have plently of experience with being a zillion miles from a station. At
those times I start to think that having a good radio and good antennas is a
wise and cost effective thing to do. But do what you want.
>
> --------
> Eric M. Jones
> www.PerihelionDesign.com
> 113 Brentwood Drive
> Southbridge, MA 01550
> (508) 764-2072
> emjones(at)charter.net
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=367293#367293
>
>
________________________________________________________________________________
| From: | "Noel Loveys" <noelloveys(at)yahoo.ca> |
| Subject: | Re: Dipole antenna fabrication |
Bob:
Have you ever used a broadband windom antenna?
Noel
-----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
Sent: February 27, 2012 1:06 AM
Subject: Re: AeroElectric-List: Re: Dipole antenna fabrication
At 11:41 AM 2/26/2012, you wrote:
The Wiki site shows a simple dipole and the caption says:
"A schematic of a half-wave dipole antenna connected to an unbalanced
coaxial cable. Better practice is to connect the balanced dipole to
the unbalanced line with a balun."
. . . and I published instructions for adding this
feature to a coax fed dipole at
http://aeroelectric.com/articles/BALUN/Balun_Fabrication.html
. . . the same technique could be applied to a comm
dipole.
I've been thinking of putting aluminum foil on the TV rabbit ears....
Which will lower the resonant frequency of the antenna
and perhaps lower the Q . . . wider bandwidth. But
no benefit for relative efficiency compared to an "ideal"
dipole at the same frequency.
Proper termination is the key to antenna efficiency. If Cessna didn't
do it, that doesn't mean the homebuilder shouldn't do it right.
I can assure you that Dr. Wood read the same books
we've all read about antennas with professional
attendance to "better practice." The point I endeavored to
make was that after he came to understand all the
deleterious effects over which we had no control on
a C-172, adding baluns on the VOR antennas yielded very
small gains compared the sum of other losses.
Next time I can get into the test lab, I'll do some
measurements on the difference between a balun-fed
dipole and a bare foot, coax-fed dipole.
Bob et al. having flown extensively in the Western states and Mexico,
I have plently of experience with being a zillion miles from a
station. At those times I start to think that having a good radio and
good antennas is a wise and cost effective thing to do. But do what you
want.
But you paint a picture suggesting that a balun would
make the difference between communicating with some distant
station . . . and not. Given the light of sight character
of VHF+ frequencies, you're more likely not to have a useable
path because you can't see the other station than because
your effective radiated signal is down by a few db due
to violations of feed point protocols. Further, it's
insufficient to be able to see the other station
peeking over the horizon (or mountaintop). The effects
of intervening "roughness" in the "Fresnel zone" can
have some profound effects on what might otherwise be
considered a free-space, line of sight situation.
http://web.arundale.co.uk/docs/ais/PathlossCalculationsforAmateurs.pdf
Mountain peaks and valleys intruding into the Fresnel
zone can kick your free space performance predictions
in the teeth.
Currents flowing on the coax shield are but part of
the 'violations' . . . the center impedance of a perfect
dipole is on the order of 73 ohms. This means that the
BEST SWR to be achieved without application of some
impedance matching is on the order of 73/50 = 1.46:1
So we've tossed off some efficiencies right out of the
box. When we plot radiation patterns on VHF antennas
on airplanes, one generally expects 10 db or greater
'lumpiness' in the pattern due to geometry of the
conductive elements around the antenna. So again,
if one is at 'extreme range' for useful communications,
it's more likely that you'll improve the path by turning
the airplane a few degrees as opposed to optimizing
feed point design.
Yes, a BALUN can be "better" but experience on small
aircraft has shown that the difference is so small
compared to all other effects combined that the balun
was not 'cost effective'. Further, it won't fix the
fundamental mis-match so 1.46:1 is still the best
we can expect. The textbooks are full of examples of
data taken from the idealized antenna and feed line
examined in the anechoic chamber with test equipment
that can split a DB into small pieces.
As soon as you put that same antenna is a real world
environment, lots of things with potential for
altering performance happen. This is why
the guy flying 'around with a radio capable of
talking to another one just like it 1000 miles
away finds that the practical limits are much
shorter for reasons mostly beyond control of
the antenna designer.
But just for grins, I've got some DIY antenna's I've
used in my weekend seminars and articles. I'll
fit one with a balun and leave the other barefoot.
Then see if my buddy Don P can tell the
difference without looking to see which one is
hooked up. Hmmmm . . . I think I know how to
do the experiment with equipment I have. Need
warmer weather though . . .
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Dipole antenna fabrication |
At 05:12 PM 2/27/2012, you wrote:
>
>Bob:
>
> Have you ever used a broadband windom antenna?
No, I've known hams that did. Most of my activity
for the past 40 years has been on 2M repeaters.
In the picture at . . .
http://aeroelectric.com/Pictures/Misc/KTVH.jpg
you can see the toes of my boots while peering
down the center of KTVH tower east of Hutchinson
KS. I was standing on the 1200' platform were
the 22/82 repeater was quartered back then.
Antennas to die for on that system were things
like DB-228 arrays of 8 dipoles on a mast about
40' long and weighing in at 75 pounds. Got to
hang two of those off the leg of this tower
about 100' apart.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Dipole antenna fabrication |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
> Bob N. said: But you paint a picture suggesting that a balun would make the difference
between communicating with some distant
> station . . . and not.
No, I didn't. Not at all. But I've flown across western stretches (Try Bishop to
Death Valley, pardner...). No Radar, no flight following, no radio communication
of any kind. I've also flown all over Mexico, where radio relay from plane-to-plane-station
is how it's done. In Baja, communications with the mainland
is typical...and very hard...but HEY, it's line of sight!
I am glad to see others post good info. There are many Hams out there who are quite
skilled in this area. Thanks Jan de Jong. I'll be building one of those for
my Glastar's vertical stab.
If local ops and $100 hamburgers is all you do, Bob N. is right. If you want better
performance for little extra effort, then I'm right.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=367431#367431
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Dipole antenna fabrication |
At 07:39 AM 2/28/2012, you wrote:
> Bob N. said: But you paint a picture suggesting that a balun would
make the difference between communicating with some distant station .
. . and not.
No, I didn't. Not at all.
. . . I'm confused . . .
But I've flown across western stretches (Try Bishop to Death Valley,
pardner...). No Radar, no flight following, no radio communication of
any kind. I've also flown all over Mexico, where radio relay from
plane-to-plane-station is how it's done. In Baja, communications with
the mainland is typical...and very hard...but HEY, it's line of sight!
Okay, we're talking about fringe communications . . .
I am glad to see others post good info. There are many Hams out there
who are quite skilled in this area. Thanks Jan de Jong. I'll be
building one of those for my Glastar's vertical stab.
If local ops and $100 hamburgers is all you do, Bob N. is right. If
you want better performance for little extra effort, then I'm right.
I didn't know it was a right/wrong contest
but an quantitative evaluation of return on
investment. Did you agree that adding a balun
is unlikely to produce any observable effect
. . . yet hamburger runs makes Bob 'right'
and 'extra performance' makes him wrong
. . . ?????
Just for grins I went to the bench and set up
a receiver for 130MHz and turned on the HP
generator set for 30% AM modulation. I opened
the squelch and turned the radiated signal up
until I could just barely tell that there was
a modulated signal competing with the receiver's
noise floor at (0.10 uV); a reasonable simulation
of 'extreme fringe' communications.
I turned the signal up until I was reasonably
certain that I could deduce spoken words on
a still very noisy signal. It took 0.2 to 0.33 uV
(6 to 20 dB increase) to make that much difference.
Were I trying to carry on meaningful conversation
with cockpit ambients added in . . . maybe that
wouldn't have been enough.
If one compares balun vs. no-balun characteristics,
what factor of 'better performance' would you expect?
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Dipole antenna fabrication |
Correction of typo . . .
> It took 0.2 to 0.33 uV (6 to 10 dB increase)
> to make that much difference.
Bob . . .
________________________________________________________________________________
| From: | Jan de Jong <jan_de_jong(at)casema.nl> |
| Subject: | Re: Dipole antenna fabrication |
> I am glad to see others post good info. There are many Hams out there who are
quite skilled in this area. Thanks Jan de Jong. I'll be building one of those
for my Glastar's vertical stab.
>
I am thinking of building one of those for the Europa vertical stab as
well. The V-shape adjusts the impedance to 50 Ohms and improves
horizontal directivity . Whether it also increases bandwidth ("more
volume" - despite using cloth hanger wire?) I don't know.
Remarks:
- the lengths mentioned in the article may a little too great for
perfection when put inside a fiberglass structure, even when not touching
- the Pawsey stub could be tuned using a SWR meter and a dummy load
instead of the antenna; looking for largest possible SWR over the air
band; the transmitter used could be protected with a guaranteed load by
50 Ohm in-out voltage divider
- after that the antenna could be tuned looking for the smallest
possible SWR over the air band.
- if things are to be tuned anyway then the only concern in construction
is treating both legs of the dipole the same
I may instead go for the straight dipole as follows:
http://www.europa-aircraft.com/pdfs/buildersmanuals/CBM%20-%20ANNEX%20C.pdf
with the beads replaced by a (verified if not tuned) Pawsey stub, as
good enough.
As an added measure 2 choke baluns 1/4 wavelength apart anywhere on the
feedline would be effective.
I also found some literally orphaned DOS programs to play with:
http://www.zerobeat.net/G4FGQ/page3.html#S301%22
SOLNOID3 shows the effect of 4 turns of 5mm wire (coax) on 45mm former
(min. bending diameter) as a choke balun
LINELEN shows dipole performance in terms of losses, assuming a choke
balun. Amazingly the largest effect is the type of coax where I thought
RG58 would be good enough for my needs.
I think Bob is right - it's not all that critical. Good enough is not so
much worse than perfection.
I should get back to my regular program now from this interesting
diversion into radio.
Jan de Jong
* <http://www.zerobeat.net/G4FGQ/solnoid3.exe>*
________________________________________________________________________________
| Subject: | battery chargers |
| From: | bob noffs <icubob(at)gmail.com> |
hi bob,
saw a wedsite for ''aci'' battery chargers/tenders. are they really
better? it does seem that sometimes my schumacher tender doesn't keep my
odessey 620 fully charged.
bob noffs
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Dipole antenna fabrication |
At 02:54 PM 2/29/2012, you wrote:
>
Did some further study on baluns in general and the
Pawsey stub in particular. I discovered an interesting
article supported by bench testing on good equipment.
I captured the article with the intent of mirroring
it on aeroelectric.com
I made an unhappy discovery that there were a number
of html syntax errors in the index of articles pertaining
to antenna issues which I've corrected. The errors
broke links to a number of antenna features. I believe
they're fixed and all is right with the world . . . at
least under the heading of "Antennas, Feedlines and Connectors"
In addition to the balun article, you'll find a compendium
of Bob Archer articles that I uploaded to the website several
years ago . . . and then left them dangling link-less.
See:
http://tinyurl.com/857u8x8
In the Huggins balun article I spotted a some toe-stubbers
like, "Velocity Factor actually varies from 0.7 to over
1 depending . . ." Of course, the velocity factor could
never exceed 1.0.
Aside from a few items that would benefit from editing,
I found the article informative.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Dipole antenna fabrication |
| From: | Robert Borger <rlborger(at)mac.com> |
Bob,
Speaking of Bob Archer and his antennas=85
I was able to connect my new Red Dot analyzer into the line between my
MicroAir 760 and the Bob Archer antenna I have mounted in the vertical
stab of the Europa.
Here's a picture of the antenna installation:
The coax termination to antenna is as per Archer's instructions. Crimp
eyelets on to the central conductor and onto a braid made from the
shield wire. Apply some shrink tube on the braid and coax for
insulation and support. Then attach the eyelets to the antenna with
nuts & lock washers over the screw posts.
Always looked pretty crude to me, but those were the instructions so I
that's what I did.
Measured SWR 1:1.2 Not bad at all.
Blue skies & tailwinds,
Bob Borger
Europa XS Tri, Rotax 914, Airmaster C/S Prop.
Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP
3705 Lynchburg Dr.
Corinth, TX 76208-5331
Cel: 817-992-1117
rlborger(at)mac.com
On Mar 1, 2012, at 11:59 AM, Robert L. Nuckolls, III wrote:
> At 02:54 PM 2/29/2012, you wrote:
>>
>
> Did some further study on baluns in general and the
> Pawsey stub in particular. I discovered an interesting
> article supported by bench testing on good equipment.
>
> I captured the article with the intent of mirroring
> it on aeroelectric.com
>
> I made an unhappy discovery that there were a number
> of html syntax errors in the index of articles pertaining
> to antenna issues which I've corrected. The errors
> broke links to a number of antenna features. I believe
> they're fixed and all is right with the world . . . at
> least under the heading of "Antennas, Feedlines and Connectors"
>
> In addition to the balun article, you'll find a compendium
> of Bob Archer articles that I uploaded to the website several
> years ago . . . and then left them dangling link-less.
>
> See:
>
> http://tinyurl.com/857u8x8
>
> In the Huggins balun article I spotted a some toe-stubbers
> like, "Velocity Factor actually varies from 0.7 to over
> 1 depending . . ." Of course, the velocity factor could
> never exceed 1.0.
>
> Aside from a few items that would benefit from editing,
> I found the article informative.
>
> Bob . . .
>
>
>
>
________________________________________________________________________________
| From: | Jan de Jong <jan_de_jong(at)casema.nl> |
| Subject: | Re: Dipole antenna fabrication |
Thank you Bob,
1. The Morris and Bob Archer pdf's are still not available from the
index I'm afraid but can be found using the search facility.
2. The Higgins measurements made me think that a simple VSWR meter might
be used to tune a Pawsey stub in the presence of a dielectric other than
air.
What bothers me is that Mr Higgins seems to measure a velocity factor of
1.07 (322 / 300). I wonder what might account for that.
Fascinating stuff that almost makes me buy a simple antenna & complex
impedance analyzer. But not quite (yet).
Jan de Jong
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Dipole antenna fabrication |
At 02:00 PM 3/1/2012, you wrote:
>
>Thank you Bob,
>
>1. The Morris and Bob Archer pdf's are still not available from the
>index I'm afraid but can be found using the search facility.
Thanks for the heads-up. I think it's fixed now.
Found a couple more un-linked features.
>2. The Higgins measurements made me think that a simple VSWR meter
>might be used to tune a Pawsey stub in the presence of a dielectric
>other than air.
Yeah . . . that's worth some tinkering time on the
workbench. Don't have time right now but I've got
lots of coax scraps that I can used to refine my
own understanding.
>What bothers me is that Mr Higgins seems to measure a velocity
>factor of 1.07 (322 / 300). I wonder what might account for that.
I didn't catch those warts the first time I read the
article. I was too fascinated by the test data. I'll
but this on my list of things to read. I think there
are links to contact him directly. I'll verify any
'fixes' to the article with him directly.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Dipole antenna fabrication |
>
>Always looked pretty crude to me, but those were the instructions so
>I that's what I did.
>
>Measured SWR 1:1.2 Not bad at all.
Not surprised. I suspect that Bob's fabrication of
the gamma-match and associated capacitor are designed
to tune out much of the reactance added by the bare,
non-coaxial lead wires. The wide geometry of the
radiating elements do doubt contributes to a wider
performance band-width.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: battery chargers |
At 10:30 AM 3/1/2012, you wrote:
>hi bob,
> saw a wedsite for ''aci'' battery chargers/tenders. are they
> really better? it does seem that sometimes my schumacher tender
> doesn't keep my odessey 620 fully charged.
> bob noffs
Can't tell you . . . I have no data either anecdotally
or measured to say that one is 'better' than the other.
Which model Schumacher are you using? Did it ever work?
When you put a voltmeter on a stored battery (charging
has been done for a day or two, what do you read?
I monitored the performance of a Schumacher 1562 (now
obsolete) a few years ago and got a righteous plot
http://www.aeroelectric.com/Pictures/Curves/schumacher_3.jpg
Without doing a similar exercise on your particular
charger, I'm unable to offer any judgement about its
condition. What makes you think it's not keeping
the 620 charged. It's possible that the charger is fine
and the battery's capacity has degraded.
If you do replace your Schumacher charger, you can send
it to me and I'll have it stroke a dead battery to see
if it's working right.
Bob . . .
________________________________________________________________________________
| From: | Ralph Finch <ralphmariafinch(at)gmail.com> |
| Subject: | Re: battery chargers |
Aviation Consumer, October 2011, reviewed battery chargers and their
headline said:
Battery Chargers: VDC in a Walk
VDC makes the only low-cost aviation-specific charger and using it can
extend battery life by months. There are several models to pick from.
They have a charger specific to the Odessey:
http://www.batteryminders.com/batterycharger/catalog/BatteryMINDer-Aviation-Specific-12-Volt-8A-Odyssey-Speci-p-16168.html
On Thu, Mar 1, 2012 at 8:30 AM, bob noffs wrote:
> hi bob,
> saw a wedsite for ''aci'' battery chargers/tenders. are they really
> better? it does seem that sometimes my schumacher tender doesn't keep my
> odessey 620 fully charged.
> bob noffs
________________________________________________________________________________
| Subject: | Re: battery chargers |
| From: | bob noffs <icubob(at)gmail.com> |
hi bob, i have had the schumacher 1562[?] on my 620 every day of the
battery's life. plane only first flew last fall so battery has not gotten
much use but it is at least 5 yrs old. charging is usually not an issue but
twice battery would not crank engine on initial start up. i was going to
have the battery load tested but then it functioned fine so the feeling
went away. strange but it only took 20-30 minutes to bring the battery up
to full charge with a 12 AMP CHARGER. anyway, i don't mean to imply i have
a problem i am looking for answers to. i was curious about this ''new''
charger as they more or less stated that fiberglass mat batteries require a
different type of maintainer. these new chargers have starting amps of 1,3,
or 7 amps and taper down from there. was wondering if conditions might stop
a schumacher from getting battery to full charge? i usually see 14 volts
when i think to check it. i couldn't say what voltage was on the 2
occasions it wouldn't turn over the engine.
bob noffs
On Thu, Mar 1, 2012 at 5:30 PM, Ralph Finch wrote:
> ralphmariafinch(at)gmail.com>
>
> Aviation Consumer, October 2011, reviewed battery chargers and their
> headline said:
>
> Battery Chargers: VDC in a Walk
> VDC makes the only low-cost aviation-specific charger and using it can
> extend battery life by months. There are several models to pick from.
>
> They have a charger specific to the Odessey:
>
> http://www.batteryminders.com/batterycharger/catalog/BatteryMINDer-Aviation-Specific-12-Volt-8A-Odyssey-Speci-p-16168.html
>
> On Thu, Mar 1, 2012 at 8:30 AM, bob noffs wrote:
> > hi bob,
> > saw a wedsite for ''aci'' battery chargers/tenders. are they really
> > better? it does seem that sometimes my schumacher tender doesn't keep my
> > odessey 620 fully charged.
> > bob noffs
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: battery chargers |
At 06:23 PM 3/1/2012, you wrote:
hi bob, i have had the schumacher 1562[?] on my 620 every day of the
battery's life. plane only first flew last fall so battery has not
gotten much use but it is at least 5 yrs old. charging is usually not
an issue but twice battery would not crank engine on initial start up.
Any time the battery wont crank the engine after
sitting on a maintainer for any length of time,
The charger, the battery or both are suspect.
i was going to have the battery load tested but then it functioned
fine so the feeling went away. strange but it only took 20-30 minutes
to bring the battery up to full charge with a 12 AMP CHARGER.
Which suggests that the battery is down to 6 a.h. or so.
Anyway, i don't mean to imply i have a problem i am looking for
answers to. i was curious about this ''new'' charger as they more or
less stated that fiberglass mat batteries require a different type of
maintainer.
Not true . . .
These new chargers have starting amps of 1,3, or 7 amps and taper
down from there. was wondering if conditions might stop a schumacher
from getting battery to full charge?
If it's a real charger/maintainer and features a top-off
cycle of 14.5 volts or more, then any size charger will
bring any size battery up to snuff. It's just a matter of
time.
My portable power batteries (50AH and 32 AH in parallel)
have been brought up on a 0.7A Battery Tender. The light
may stay red for a couple of days but it eventually
gets the job done.
I usually see 14 volts when i think to check it. i couldn't say what
voltage was on the 2 occasions it wouldn't turn over the engine.
Suggest you do a cap-check on the battery. What
you've related thus far suggests the battery
is not airworthy.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Transponder antenna available |
I was digging around in the goodies box looking
for a missing crimp tool and found this puppy . . .
Emacs!
I don't think this has ever been installed.
$15 postage paid to first interested individual . . .
Bob . . .
________________________________________________________________________________
| From: | Mike Nellis <mike(at)bmnellis.com> |
| Subject: | Re: Transponder antenna available |
On Friday, March 02, 2012 1:09:00 PM, Robert L. Nuckolls, III wrote:
> I was digging around in the goodies box looking
> for a missing crimp tool and found this puppy . . .
>
> Emacs!
>
> I don't think this has ever been installed.
>
> $15 postage paid to first interested individual . . .
>
> Bob . . .
>
I'll take it off your hand Bob. Do you take credit cards or PayPal?
Other wise I'll stick $15 in an envelope.
________________________________________________________________________________
| From: | Charlie England <ceengland(at)bellsouth.net> |
| Subject: | Re: Transponder antenna available |
On 03/02/2012 01:09 PM, Robert L. Nuckolls, III wrote:
> I was digging around in the goodies box looking
> for a missing crimp tool and found this puppy . . .
>
>
> I don't think this has ever been installed.
>
> $15 postage paid to first interested individual . . .
>
> Bob . . .
>
I'll take it, and thanks! How/where do you want payment?
I can do Paypal, credit card, check, etc.
I'll send my address to your email address.
Thanks again,
Charlie
ceengland(at)bellsouth.net
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Transponder antenna available |
At 01:21 PM 3/2/2012, you wrote:
>
>On Friday, March 02, 2012 1:09:00 PM, Robert L. Nuckolls, III wrote:
>>I was digging around in the goodies box looking
>>for a missing crimp tool and found this puppy . . .
>>
>>Emacs!
>>
>>I don't think this has ever been installed.
>>
>>$15 postage paid to first interested individual . . .
>>
>>Bob . . .
>
>I'll take it off your hand Bob. Do you take credit cards or PayPal?
>Other wise I'll stick $15 in an envelope.
You got it. I'll invoice you on PayPal.
Bob . . .
________________________________________________________________________________
| Subject: | Radio speaker volume control |
| From: | Paul Kuntz <paul.r.kuntz(at)gmail.com> |
I have a small 8-ohm speaker that I plan to connect to the speaker output
of my XCOM-760 radio. For speaker volume control, do I simply wire a
potentiometer into one of the wires going to the speaker, introducing a
variable resistance in series with the speaker coil, or is something more
specialized necessary?
Regards,
Paul Kuntz
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Radio speaker volume control |
At 04:06 PM 3/2/2012, you wrote:
>I have a small 8-ohm speaker that I plan to connect to the speaker
>output of my XCOM-760 radio. For speaker volume control, do I
>simply wire a potentiometer into one of the wires going to the
>speaker, introducing a variable resistance in series with the
>speaker coil, or is something more specialized necessary?
There's a specialized device for direct
control of speaker volume called an L-pad
which has all the appearances of an ordinary
potentiometer . . .
Emacs!
. . . but specifically designed to work with
low impedance speakers. See:
http://tinyurl.com/84jwt7v
I think that radio's volume control affects
both the headset and speaker volumes. Do you
anticipate simultaneous use of both headphones
and speaker such that independent control of
each is necessary? If so, it could be that
setting the radio's volume for the desired headset
level will leave you short on speaker volume
so that even with the l-pad set for wide-open,
the speaker volume is found wanting.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Radio speaker volume control |
| From: | Tim Andres <tim2542(at)sbcglobal.net> |
Paul the Icom A210 may be different, but on my plane I just used a SPST swit
ch to turn the speaker on/off. Then the volume controls the speaker and head
phones if the speaker is selected on, of course I don't use both at the same
time so this has worked great.
Tim
Sent from my iPad
On Mar 2, 2012, at 2:06 PM, Paul Kuntz wrote:
> I have a small 8-ohm speaker that I plan to connect to the speaker output o
f my XCOM-760 radio. For speaker volume control, do I simply wire a potenti
ometer into one of the wires going to the speaker, introducing a variable re
sistance in series with the speaker coil, or is something more specialized n
ecessary?
>
> Regards,
> Paul Kuntz
>
>
==========================
=========
==========================
=========
==========================
=========
==========================
=========
>
________________________________________________________________________________
| Subject: | Re: Radio speaker volume control |
| From: | Paul Kuntz <paul.r.kuntz(at)gmail.com> |
Bob,
Thanks a lot for your quick and helpful reply. You are correct about there
being only one volume control for headsets and speaker on this radio, and
your comment about the relative volume of headsets and speaker was was
right on. As soon as I read your reply, I went to the plane and hooked up
the speaker, which arrived in the mail today. With the headset volume at a
comfortable level, the speaker is audible at a level that doesn't need to
be turned down further with a volume control, so adding a separate speaker
volume control seems pointless.
The L-pad tip was educational, nevertheless. It's now part of the great
education in aircraft electrical systems that I have received from this
forum, your excellent book and your posts here over the past several years.
Regards,
Paul Kuntz
On Fri, Mar 2, 2012 at 5:27 PM, Robert L. Nuckolls, III <
nuckolls.bob(at)aeroelectric.com> wrote:
> At 04:06 PM 3/2/2012, you wrote:
>
> I have a small 8-ohm speaker that I plan to connect to the speaker output
> of my XCOM-760 radio. For speaker volume control, do I simply wire a
> potentiometer into one of the wires going to the speaker, introducing a
> variable resistance in series with the speaker coil, or is something more
> specialized necessary?
>
>
> There's a specialized device for direct
> control of speaker volume called an L-pad
> which has all the appearances of an ordinary
> potentiometer . . .
>
> [image: Emacs!]
>
>
> . . . but specifically designed to work with
> low impedance speakers. See:
>
> * http://tinyurl.com/84jwt7v*
>
> I think that radio's volume control affects
> both the headset and speaker volumes. Do you
> anticipate simultaneous use of both headphones
> and speaker such that independent control of
> each is necessary? If so, it could be that
> setting the radio's volume for the desired headset
> level will leave you short on speaker volume
> so that even with the l-pad set for wide-open,
> the speaker volume is found wanting.
>
> **
>
> ** Bob . . .
>
________________________________________________________________________________
| Subject: | Re: Radio speaker volume control |
| From: | Paul Kuntz <paul.r.kuntz(at)gmail.com> |
Tim,
I agree. A switch to turn the speaker on and off is really all that's
needed, and even that seems somewhat redundant. See my other post just
before this one.
For pre-flight and post-flight radio use with the engine off, having the
speaker on all the time seems just fine. With the engine running that the
headsets at a comfortable volume, I suspect the speaker will be drowned out
by engine noise.
Regards,
Paul Kuntz
On Fri, Mar 2, 2012 at 6:22 PM, Tim Andres wrote:
> Paul the Icom A210 may be different, but on my plane I just used a SPST
> switch to turn the speaker on/off. Then the volume controls the speaker and
> headphones if the speaker is selected on, of course I don't use both at the
> same time so this has worked great.
> Tim
>
> Sent from my iPad
>
> On Mar 2, 2012, at 2:06 PM, Paul Kuntz wrote:
>
> I have a small 8-ohm speaker that I plan to connect to the speaker output
> of my XCOM-760 radio. For speaker volume control, do I simply wire a
> potentiometer into one of the wires going to the speaker, introducing a
> variable resistance in series with the speaker coil, or is something more
> specialized necessary?
>
> Regards,
> Paul Kuntz
>
> *
>
> *
>
> *
>
> *
>
>
________________________________________________________________________________
| Subject: | Lowrance 2000C NMEA/DGPS Adapter cable NDC-2 |
| From: | Sam Staton <pj260(at)bellsouth.net> |
Folks -
I am attempting to get some use out of my orphan Lowrance GPS. I need
to obtain the adapter cable that allows it to talk to other devices. It would
seem that no one in this country has one for sale. My hope is that someone on
the list has one they don't need and we can make a deal. Thanks in advance!
Sam Staton
Jacksonville, Fl
(904) 223-9627
pj269(at)bellsouth.net
Sent from my iPad
________________________________________________________________________________
| Subject: | Lowrance 2000C NMEA/DGPS Adapter cable NDC-2 |
| From: | Sam Staton <pj260(at)bellsouth.net> |
If I have multiple posted this, please forgive my error! I am trying to get some
use out of my orphan Lowrance GPS. I need to obtain the NMEA/DGPS adapter cable
(NDC-2, Lowrance part number 101-36). I have not been able to find one for
sale anywhere in this country. If someone on the list has one and doesn't have
a need for it, please contact me!
Sam Staton
Jacksonville, FL
(904) 223-9627
pj260(at)bellsouth.net
Sent from my iPad
________________________________________________________________________________
| Subject: | Burnouts Arbitrary? |
I have a Garmin 340 which burned up a main board a few weeks ago. Garmin ga
ve no particular excuse for the failure, so I thought I'd throw out the que
stion.
- Is it common for Audio Panels to self destruct? Mine is about 8
years old and worked normally up to the minute it failed.
- The repair was flat rate at $600.00 so I don't want to throw it
back in and have it go up in smoke again.
- Any tests I can perform? I am using 5 amp ATC fuse(s) for power.
I believe that is the recommended size.
- The audio cables are custom built from Approach Fast Stack and h
ave not been altered since new.
Thanks for the ideas.
Glenn
0
t
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Burnouts Arbitrary? |
At 09:36 AM 3/3/2012, you wrote:
>I have a Garmin 340 which burned up a main board a few weeks ago.
>Garmin gave no particular excuse for the failure, so I thought I'd
>throw out the question.
>
>- Is it common for Audio Panels to self destruct? Mine is
>about 8 years old and worked normally up to the minute it failed.
No
>- The repair was flat rate at $600.00 so I don't want to
>throw it back in and have it go up in smoke again.
Did it actually 'smoke' . . . or at least smell bad?
>- Any tests I can perform? I am using 5 amp ATC fuse(s) for
>power. I believe that is the recommended size.
Sure, testing with a small fuse is one useful technique. I
use a current limited power supply for similar explorations.
You can set the short circuit current to any level from a
few milliamps up to full output from the supply. Let's you
explore a circuit's power management condition with little
risk of subjecting it to further damage.
Have you had it open? Can you see any char or signs of
overheating? A experienced bench technician can do the
sniff test and tell whether it's a component or burned
trace .. . but if it's a burned trace . . . it will be
obvious. Smoked integrated circuits can be hard to spot
sometimes.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Lowrance 2000C NMEA/DGPS Adapter cable NDC-2 |
At 08:05 AM 3/3/2012, you wrote:
>
>If I have multiple posted this, please forgive my error! I am trying
>to get some use out of my orphan Lowrance GPS. I need to obtain the
>NMEA/DGPS adapter cable (NDC-2, Lowrance part number 101-36). I have
>not been able to find one for sale anywhere in this country. If
>someone on the list has one and doesn't have a need for it, please contact me!
You can make one for a few dollars. The pinouts are
here:
http://pinouts.ru/pin_GPS.shtml
Lowrance seems fond of propriatary connectors
so you might have to jury-rig a connector using
pins from another connector and some epoxy
putty to craft a "body". Looks messy but it works.
Bob . . .
________________________________________________________________________________
| From: | Hopperdhh(at)aol.com |
| Subject: | Re: battery chargers |
It would have to extend it by a lot of months to pay for itself. My last
PC680 lasted 5 years without any help from a battery tender. That includes
sitting for 3 or 4 weeks at a time during the Indiana winters with no
charger at all. I finally replaced it even though it was still cranking my
IO-360 fine, even on some hot starts that took 15 or 20 seconds. I was
starting to worry that the vibration could be getting to it. I didn't want it
to
blow up!!
You could buy another battery for less than the price of the battery
tender. Am I missing something here?
Dan
RV-7A - N766DH - flying 7 years
In a message dated 3/1/2012 6:32:40 P.M. Eastern Standard Time,
ralphmariafinch(at)gmail.com writes:
--> AeroElectric-List message posted by: Ralph Finch
Aviation Consumer, October 2011, reviewed battery chargers and their
headline said:
Battery Chargers: VDC in a Walk
VDC makes the only low-cost aviation-specific charger and using it can
extend battery life by months. There are several models to pick from.
They have a charger specific to the Odessey:
http://www.batteryminders.com/batterycharger/catalog/BatteryMINDer-Aviation-
Specific-12-Volt-8A-Odyssey-Speci-p-16168.html
On Thu, Mar 1, 2012 at 8:30 AM, bob noffs wrote:
> hi bob,
> saw a wedsite for ''aci'' battery chargers/tenders. are they really
> better? it does seem that sometimes my schumacher tender doesn't keep my
> odessey 620 fully charged.
> bob noffs
________________________________________________________________________________
| Subject: | Re: Lowrance 2000C NMEA/DGPS Adapter cable NDC-2 |
| From: | bob noffs <icubob(at)gmail.com> |
fwiw, i have found a hot glue gun really handy for ''potting'' some
things.i have used it for making a connector many times.
bob noffs
On Sat, Mar 3, 2012 at 10:23 AM, Robert L. Nuckolls, III <
nuckolls.bob(at)aeroelectric.com> wrote:
> nuckolls.bob(at)aeroelectric.com**>
>
>
> At 08:05 AM 3/3/2012, you wrote:
>
>>
>> If I have multiple posted this, please forgive my error! I am trying to
>> get some use out of my orphan Lowrance GPS. I need to obtain the NMEA/DGPS
>> adapter cable (NDC-2, Lowrance part number 101-36). I have not been able to
>> find one for sale anywhere in this country. If someone on the list has one
>> and doesn't have a need for it, please contact me!
>>
>
> You can make one for a few dollars. The pinouts are
> here:
>
> http://pinouts.ru/pin_GPS.**shtml
>
> Lowrance seems fond of propriatary connectors
> so you might have to jury-rig a connector using
> pins from another connector and some epoxy
> putty to craft a "body". Looks messy but it works.
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | "David Lloyd" <skywagon(at)charter.net> |
| Subject: | Re: battery chargers |
Dan,
Many battery "maintainers/tenders" are well under $25 and do a very good
job. That is certainly less than the cost of a new Gill or Concorde.
David
-------------------------------------------------------------------------
-------
----- Original Message -----
From: Hopperdhh(at)aol.com
To: aeroelectric-list(at)matronics.com
Sent: Saturday, March 03, 2012 9:08 AM
Subject: Re: AeroElectric-List: battery chargers
It would have to extend it by a lot of months to pay for itself. My
last PC680 lasted 5 years without any help from a battery tender. That
includes sitting for 3 or 4 weeks at a time during the Indiana winters
with no charger at all. I finally replaced it even though it was still
cranking my IO-360 fine, even on some hot starts that took 15 or 20
seconds. I was starting to worry that the vibration could be getting to
it. I didn't want it to blow up!!
You could buy another battery for less than the price of the battery
tender. Am I missing something here?
Dan
RV-7A - N766DH - flying 7 years
In a message dated 3/1/2012 6:32:40 P.M. Eastern Standard Time,
ralphmariafinch(at)gmail.com writes:
Aviation Consumer, October 2011, reviewed battery chargers and their
headline said:
Battery Chargers: VDC in a Walk
VDC makes the only low-cost aviation-specific charger and using it
can
extend battery life by months. There are several models to pick
from.
They have a charger specific to the Odessey:
http://www.batteryminders.com/batterycharger/catalog/BatteryMINDer-Aviati
on-Specific-12-Volt-8A-Odyssey-Speci-p-16168.html
On Thu, Mar 1, 2012 at 8:30 AM, bob noffs wrote:
> hi bob,
> saw a wedsite for ''aci'' battery chargers/tenders. are they
really
> better? it does seem that sometimes my schumacher tender doesn't
keep my
> odessey 620 fully charged.
> bob = Use ilities ay - MATRONICS WEB
FORUMS - List Contribution Web Site p;
________________________________________________________________________________
| Subject: | Re: battery chargers |
| From: | bob noffs <icubob(at)gmail.com> |
thanks bob, as the prop was sent out to be shortened i guess no time like
the present to pull the battery and get a load test done.
bob noffs
On Thu, Mar 1, 2012 at 10:42 PM, Robert L. Nuckolls, III <
nuckolls.bob(at)aeroelectric.com> wrote:
> nuckolls.bob(at)aeroelectric.com**>
>
>
> At 06:23 PM 3/1/2012, you wrote:
> hi bob, i have had the schumacher 1562[?] on my 620 every day of the
> battery's life. plane only first flew last fall so battery has not gotten
> much use but it is at least 5 yrs old. charging is usually not an issue but
> twice battery would not crank engine on initial start up.
>
> Any time the battery wont crank the engine after
> sitting on a maintainer for any length of time,
> The charger, the battery or both are suspect.
>
>
> i was going to have the battery load tested but then it functioned fine so
> the feeling went away. strange but it only took 20-30 minutes to bring the
> battery up to full charge with a 12 AMP CHARGER.
>
> Which suggests that the battery is down to 6 a.h. or so.
>
>
> Anyway, i don't mean to imply i have a problem i am looking for answers
> to. i was curious about this ''new'' charger as they more or less stated
> that fiberglass mat batteries require a different type of maintainer.
>
> Not true . . .
>
>
> These new chargers have starting amps of 1,3, or 7 amps and taper down
> from there. was wondering if conditions might stop a schumacher from
> getting battery to full charge?
>
> If it's a real charger/maintainer and features a top-off
> cycle of 14.5 volts or more, then any size charger will
> bring any size battery up to snuff. It's just a matter of
> time.
>
> My portable power batteries (50AH and 32 AH in parallel)
> have been brought up on a 0.7A Battery Tender. The light
> may stay red for a couple of days but it eventually
> gets the job done.
>
>
> I usually see 14 volts when i think to check it. i couldn't say what
> voltage was on the 2 occasions it wouldn't turn over the engine.
>
> Suggest you do a cap-check on the battery. What
> you've related thus far suggests the battery
> is not airworthy.
>
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | "David Lloyd" <skywagon(at)charter.net> |
| Subject: | Re: Lowrance 2000C NMEA/DGPS Adapter cable NDC-2 |
Bob,
Thanks for the link to GPS receiver "pin-outs.....
Dave
____________________________________________
----- Original Message -----
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com>
Sent: Saturday, March 03, 2012 8:23 AM
Subject: Re: AeroElectric-List: Lowrance 2000C NMEA/DGPS Adapter cable NDC-2
>
>
> At 08:05 AM 3/3/2012, you wrote:
>>
>>If I have multiple posted this, please forgive my error! I am trying to
>>get some use out of my orphan Lowrance GPS. I need to obtain the NMEA/DGPS
>>adapter cable (NDC-2, Lowrance part number 101-36). I have not been able
>>to find one for sale anywhere in this country. If someone on the list has
>>one and doesn't have a need for it, please contact me!
>
> You can make one for a few dollars. The pinouts are
> here:
>
> http://pinouts.ru/pin_GPS.shtml
>
> Lowrance seems fond of propriatary connectors
> so you might have to jury-rig a connector using
> pins from another connector and some epoxy
> putty to craft a "body". Looks messy but it works.
>
> Bob . . .
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Lowrance 2000C NMEA/DGPS Adapter cable NDC-2 |
At 11:36 AM 3/3/2012, you wrote:
>fwiw, i have found a hot glue gun really handy for ''potting'' some
>things.i have used it for making a connector many times.
> bob noffs
Yes! I've steered away from using hot-glue connector
work-arounds in mobile environments. It gets pretty
hot inside some closed vehicles and that stuff softens
easily. But it's been very useful as a potting compound. I've
"spider-webbed" circuits together onto the back side
of a d-sub connector, mounted in a sturdy copper-clad
box and supported the components with hot-glue. Even
when soft, it will provide adequate support to the
components and, of course, it is non-conductive.
Bob . . .
________________________________________________________________________________
| From: | Hopperdhh(at)aol.com |
| Subject: | Re: battery chargers |
Hi David,
I agree with you on the type of battery you mention. Although, I don't
know anything about a $15 tender. If the electrolyte level gets low you can
have an explosion. How do I know that?!!
The tender in the link costs about $200 and is specific to the Odyssey.
The Odyssey has a very slow self discharge rate compared to wet batteries,
and shouldn't need to be charged unless there is a constant load of some
kind on it. My plane doesn't have anything drawing current when it is off.
Dan
In a message dated 3/3/2012 12:38:19 P.M. Eastern Standard Time,
skywagon(at)charter.net writes:
Dan,
Many battery "maintainers/tenders" are well under $25 and do a very good
job. That is certainly less than the cost of a new Gill or Concorde.
David
____________________________________
----- Original Message -----
From: _Hopperdhh(at)aol.com_ (mailto:Hopperdhh(at)aol.com)
(mailto:aeroelectric-list(at)matronics.com)
Sent: Saturday, March 03, 2012 9:08 AM
Subject: Re: AeroElectric-List: battery chargers
It would have to extend it by a lot of months to pay for itself. My last
PC680 lasted 5 years without any help from a battery tender. That includes
sitting for 3 or 4 weeks at a time during the Indiana winters with no
charger at all. I finally replaced it even though it was still cranking my
IO-360 fine, even on some hot starts that took 15 or 20 seconds. I was
starting to worry that the vibration could be getting to it. I didn't want it
to
blow up!!
You could buy another battery for less than the price of the battery
tender. Am I missing something here?
Dan
RV-7A - N766DH - flying 7 years
In a message dated 3/1/2012 6:32:40 P.M. Eastern Standard Time,
ralphmariafinch(at)gmail.com writes:
Aviation Consumer, October 2011, reviewed battery chargers and their
headline said:
Battery Chargers: VDC in a Walk
VDC makes the only low-cost aviation-specific charger and using it can
extend battery life by months. There are several models to pick from.
They have a charger specific to the Odessey:
http://www.batteryminders.com/batterycharger/catalog/BatteryMINDer-Aviation-
Specific-12-Volt-8A-Odyssey-Speci-p-16168.html
On Thu, Mar 1, 2012 at 8:30 AM, bob noffs wrote:
> hi bob,
> saw a wedsite for ''aci'' battery chargers/tenders. are they really
> better? it does seem that sometimes my schumacher tender doesn't keep my
> odessey 620 fully charged.
> bob = Use ilities ay - MATRONICS WEB FORUMS -
List Contribution Web Site p;
href="http://www.matronics.com/Navigator?AeroElectric-List">http://www.matronics.com/Navigator?AeroElectric-List
href="http://forums.matronics.com">http://forums.matronics.com
href="http://www.matronics.com/contribution">http://www.matronics.com/c
(http://www.matronics.com/Navigator?AeroElectric-List)
(http://www.matronics.com/contribution)
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: battery chargers |
At 11:38 AM 3/3/2012, you wrote:
>thanks bob, as the prop was sent out to be shortened i guess no time
>like the present to pull the battery and get a load test done.
LOAD and CAPACITY. That's one of the characteristics of
SLVA batteries that tends to convince us they are
flightworthy when in fact, they may not be.
Their internal impedance is so much lower than a
flooded battery that their capacity might well have
dropped below your design goals for battery-only
operations and still get the engine started.
One of our members just completed the 'po boy's
cap checker described here:
Emacs!
After you've LOAD tested a battery to see what current it
will deliver when loaded down to 9v for 15 seconds, you
recharge it and put this fixture on it, set the clock for
noon (or midnight) and push the button. The relay will
pull in and light the lamp thus placing about a 4A load
on the battery. Adjust the number and size of lamps in
parallel to get a load that approximates your alternator-out
loads.
When the relay drops, the clock stops and you've got a
benchmark for how well the battery will support your
electro-whizzies with a failed alternator. Batteries
are mostly replaced in the heavy GA iron because they
won't power the goodies . . . not because they won't
start the engine.
Bob . . .
________________________________________________________________________________
| From: | Jeff Page <jpx(at)qenesis.com> |
| Subject: | Lamar DSX1240-1 Alternator overvoltage protection |
Does anyone have additional information concerning the Lamar 40A
alternator, part number DSX1240-1 ?
A fellow builder purchased one from his engine builder and wants to
add overvoltage protection.
The website seems to be non-functional at the moment, so I have
attached the diagram provided in the minimal installation
instructions. If the attachment doesn't come through, you can see the
diagram here:
http://www.qenesis.com/Temp/LamarDSX1240-1.jpg
To me, it looks like the separate connection for the field wire should
work nicely with a typical overvoltage protection circuit designed to
pop the breaker.
Does anyone have specific knowledge or experience to know this will work ?
The "alternator warning light" wiring is incompatible with an
overvoltage protection circuit, since after the breaker has popped,
the indicator cannot possible come on.
Does anyone know if that indicator, supplied by another circuit, would
correctly indicate a low voltage condition if the field supply is
disconnected by the popped breaker ?
Thanks,
Jeff Page
Dream Aircraft Tundra #10
________________________________________________________________________________
| Subject: | Re: Burnouts Arbitrary? |
| From: | Ed Gilroy <egilroy(at)gmail.com> |
Is your avionics fan working? Lost a Garmin GPS to that a few years back.
Sent from my iPhone
On Mar 3, 2012, at 10:36 AM, wrote:
> I have a Garmin 340 which burned up a main board a few weeks ago. Garmin g
ave no particular excuse for the failure, so I thought I=99d throw out
the question.
>
> - Is it common for Audio Panels to self destruct? Mine is about 8
years old and worked normally up to the minute it failed.
> - The repair was flat rate at $600.00 so I don=99t want to t
hrow it back in and have it go up in smoke again.
> - Any tests I can perform? I am using 5 amp ATC fuse(s) for power
. I believe that is the recommended size.
> - The audio cables are custom built from Approach Fast Stack and h
ave not been altered since new.
>
>
> Thanks for the ideas.
>
> Glenn
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> 0
> t
>
>
==========================
=========
==========================
=========
==========================
=========
==========================
=========
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: battery chargers |
At 12:29 PM 3/3/2012, you wrote:
Hi David,
I agree with you on the type of battery you
mention. Although, I don't know anything about a
$15 tender. If the electrolyte level gets low
you can have an explosion. How do I know that?!!
Let us consider the Odyssey Technical Manual which
may be downloaded from:
http://www.odysseyfactory.com/documents/US-ODY-TM-001_0411_000.pdf
First, I searched for the word "explosion" and didn't find
it.
Next I searched for the word "damage" and I find it
5 times. The word is used 4 times in the context of
mechanical damage to the battery or damage to surroundings
due to leakage.
The 5th time is used on page 13 in the context of discussing
deep discharge recovery processes. Techniques that may be
successful in recovering a battery that has been BADLY
DISCHARGED without benefit of a timely recharge.
The tender in the link costs about $200 and is
specific to the Odyssey. The Odyssey has a very
slow self discharge rate compared to wet
batteries, and shouldn't need to be charged
unless there is a constant load of some kind on it.
Or it was put away in a discharged state . . . like you've
just spent the afternoon trolling, mowing the yard with
a DC electric lawn mower, etc. etc. In situations where
the battery is used to supply a major portion of it's
rated capacity on each discharge cycle, then recharging it
in a gentle, prescribed manner may be of some benefit
to service life. But consider the use in most automotive
applications including aircraft. You use 2 to 5% off the
top to get the engine started. Then the alternator stuffs
the energy back in at a prodigious rate set by what ever
the alternator supplies over and above the vehicle's
requirements.
After some period of operation, the battery is soon topped
of and presumably remains so until the next time the
battery master is flipped on during pre-flight. It' is
quite possible . . . nay probable that all batteries aboard
airplanes are never ministered to by precision chargers . . .
further, it's not clear how a battery would benefit from
attendance by a precision charger if you DID have AC
in the hangar and plugged the airplane in until the next
flight. The particularly robust nature of the AGM battery
was cited by another reader who offered:
It would have to extend it by a lot of months to
pay for itself. My last PC680 lasted 5 years
without any help from a battery tender. That
includes sitting for 3 or 4 weeks at a time
during the Indiana winters with no charger at
all. I finally replaced it even though it was
still cranking my IO-360 fine, even on some hot
starts that took 15 or 20 seconds. I was
starting to worry that the vibration could be
getting to it. I didn't want it to blow up!!
You could buy another battery for less than the
price of the battery tender. Am I missing something here?
Concerns for blowing up AGM batteries have no foundation
in physics of design or fact of service. The majority
of liberated oxygen and hydrogen gasses never get out of
the mats else they would not be available for recombination.
I would encourage interested readers to compare the recommended
3-step charge profiles for AGM batteries. By the way, the
Odyssey is but one of MANY AGM products all of which will
benefit from the same sort of (Step 1) CC charge, (Step 2)
CV top-off, (Step 3) CV sustenance at just over the open-circuit
terminal voltage so as to offset self-discharge currents.
The product literature shown at
http://tinyurl.com/745n3tr
gives rise to a number of questions.
(1) Exactly what is meant by "aviation specific"?
The percentage of batteries used in airplanes compared
to all other applications is a spit in the ocean.
Exactly what makes the battery worthy of $200 chargers
just because it's bolted to an airplane?
(2) Then there is the "Odyssey specific" thing. I spent
a day touring the Enersys facilities in Mexico, MO a
few years back. Got to walk through the highly automated
factory and spend several hours in a conference room drinking
their sodas while a bevy of engineers and marketing people
assured me and my colleagues that the Enersys products were
drop-in replacements for Gill, Concorde, Rebatt . . . you
name it. Not one individual mentioned anything about special
considerations for Enersys products bolted to airplanes or
chargers necessary to maximize service life of an Odyssey
product.
In fact, aside from their 'pure lead' plates and highly
automated manufacturing processes, there were no claims
to fame other than absolute quality in comparison with
other AGM products . . . no special treatments expected.
(3) Then there's that "desulfator-conditioner" thing.
Skipp Koss and I have discussed the marketing hype
phenomenon surrounding so-called desulfation techniques.
A battery that is badly discharged and allowed to sit
will indeed suffer from the effects of large crystal
formation that degrades the battery's performance. The
deep discharge recovery techniques described in the Odyssey
manual cited above are about word for word equal to the
techniques described by Concorde (and I presume others).
The "aviation specific" device described does not claim
to conform with those recovery techniques. The word "sulfate"
is not mentioned in any context in the Odyssey manual.
Wikipedia speaks rather well to the sulfation process
here:
http://en.wikipedia.org/wiki/Desulfation#Sulfation_and_desulfation
But in particular, consider these statements . . .
"Sulfation can be avoided if the battery is fully
recharged immediately after a discharge cycle."
and this one . . .
SLI batteries (starting, lighting, ignition; i.e.
car batteries) have less deterioration because
they are used more frequently vs deep cycle
batteries. Deep cycle batteries tend to require
more desulfation, can suffer from overcharging,
and can be in a very large bank which leads to
unequal charging and discharging.
As discussed earlier, it's a design goal to (1) use very
little of the battery's capacity to star the engine
followed by (2) a recharge event whereupon the battery is
(3) held in a high state of charge as a reserve source
of energy in the event of alternator failure.
In this type of service, the battery can be expected to
perform for hundreds of flight cycles as long as the
battery is not put away in a degraded state of charge.
(4) Then there's the guarantee:
"We guarantee to significantly increase both your
battery's life and performance
or we will refund 100% of your money within one (1) full year. This is in
addition to our five (5) year "no hassle" warranty."
Not sure what all that means . . . but exactly how
is John Q Public pilot supposed to make a quantitative
evaluation the this charger's performance as he chooses
to use it on his airplane? Without having laboratory
grade data on batteries that failed too soon to compare
with batteries blessed with their "aviation specific" charger,
how would the dissatisfied consumer have a basis for
complaint?
(5) Then there's this notion that the battery being
put away in the hangar is suffering from any state of
discharge that calls for a kinder-gentler-precision
recharge.
(6) Finally, there's a statement in the Odyssey manual
to the effect . . .
"Small, portable automotive and powersport
chargers may also be used to charge your ODYSSEY
battery. These chargers are generally designed to
bring a discharged battery to a state of charge
(SOC) that is high enough to crank an engine.
Once the engine is successfully cranked, its
alternator should fully charge the battery. It is
important to keep in mind the design limitations
of these small chargers when using them."
and this. . .
"All ODYSSEY batteries can be quickly charged.
The graph below shows their exceptional fast
charge characteristics at a constant 14.7V for
three levels of inrush current. These current
levels are similar to the output currents of
modern automotive alternators. Table 6 and Figure
7 show the capacity returned as a function of the
magnitude of the inrush current."
"Standard internal combustion engine alternators
with an output voltage of 14.2V can also charge
these batteries. The inrush current does not need
to be limited under constant voltage charge.
However, because the typical alternator voltage
is only 14.2V instead of 14.7V, the charge times
will be longer than those shown in Table 5."
and finally this . . .
"Another class of chargers is designed
specifically to maintain a battery in a high SOC.
These chargers, normally in the 3/4 amp to 11/2
amp range, are not big enough to charge a deeply
discharged ODYSSEY=AE battery. They must only be
used either to continuously compensate for
parasitic losses or to maintain a trickle charge
on a stored battery, as long as the correct
voltages are applied. It is very important,
therefore, to ensure that the ODYSSEY battery is
fully charged before this type of charger is connected to it."
From Odyssey's own literature, we find that their
batteries can be charged under a host of protocols
as long as limits are observed. I'll argue that the
last paragraph is misleading . . .
I've used Battery Tenders for years that only put
out 3/4 of an amp or so. While under the supervision
of one of these chargers I get these behaviors
http://www.aeroelectric.com/Pictures/Curves/Battery_Tender_Recharge.pdf
with a 1.5 Schumacher I get this
http://www.aeroelectric.com/Pictures/Curves/schumacher_3.jpg
When cap-checked after being on one of these chargers,
I've had no indication whatsoever that the batteries
were incompletely charged.
I cannot see that the performance of these chargers is
inconsistent with what I read in the Odyssey technical
literature (or anyone else's for that matter. As to these
devices being "too small" . . . I put a fully charged 33 AH
AGM battery on a 100 mA constant current source and in less
than 2 minutes, the terminal voltage rose to over 15 volts.
I put the battery on a 14.7 constant voltage and in
a few minutes, the charge current had fallen to under
100 mA. From this I infer that ANY size charter is
probably capable of reaching and holding a top-off
level of 14.2 to 14.7 volts and dropping to a maintaining
level of 13.2 or so based on a nominal 'trigger' current
for calling the battery charged.
The point being that small chargers are capable of
boosting the terminal voltage to the ranges recommended
by Odyssey and others . . . it may just take more time.
Bottom line is that for the way we use batteries in cars
and airplanes (small percentage discharge cycles),
there is little benefit for having any sort of charger
. . . and at most, a $30 wall-wart Battery Tender or
this $20 Schumacher from WalMart will suffice.
Emacs!
The whole "aviation specific" and "desulfation" business
is lacking foundation for either effectiveness or necessity.
Further, specialized recharging protocols are indicated
when trying to recover a badly depleted battery . . . but
not when putting your airplane away at the end of the day.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Lamar DSX1240-1 Alternator overvoltage protection |
At 02:28 PM 3/3/2012, you wrote:
Does anyone have additional information concerning the Lamar 40A
alternator, part number DSX1240-1 ?
A fellow builder purchased one from his engine builder and wants to
add overvoltage protection.
The website seems to be non-functional at the moment, so I have
attached the diagram provided in the minimal installation
instructions. If the attachment doesn't come through, you can see the
diagram here:
http://www.qenesis.com/Temp/LamarDSX1240-1.jpg
To me, it looks like the separate connection for the field wire should
work nicely with a typical overvoltage protection circuit designed to
pop the breaker.
This diagram has the look, feel and smell of the
classic, internally regulated automotive alternator.
Modification for external regulation (Like the
B&C products) -OR- external OV protection
for the existing regulator (like PlanePower)
are the most practical approaches.
Either one requires a knowledgeable disassembly
and surgery to add OV protection to the field
supply circuit. Alternatively, one can add a
b-lead contactor and ov sensing as depicted
here:
http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z24-Interim.pdf
My best recommendation is to accomplish the
necessary changes to remove the existing
regulator and re-wire for external regulation
typical of the Z-figures.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Lowrance 2000C NMEA/DGPS Adapter cable NDC-2 |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
And maybe:
http://www.marineshop.no/PartDetail.aspx?q=p:10516242
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=367710#367710
________________________________________________________________________________
| From: | Hopperdhh(at)aol.com |
| Subject: | Re: battery chargers |
Hi Bob,
The explosion I mentioned was in reference to a flooded battery, not an
Odyssey. I once put a charger on my tractor and forgot about it. A few
weeks later I found part of the battery case about 10 feet from the tractor.
The rest of the battery was still in the tractor battery box with the
innards showing! I assume that when the electrolyte got below the top of the
plates that some conductive debris shorted between them and set off the
oxygen/hydrogen explosion. This experience has caused me to be leery of battery
tenders. This could happen with even a 1/2 amp charger because the energy
that makes the spark comes from the battery, not the charger.
Thanks for the excellent information in your post on battery chargers.
Dan
RV-7A 766DH
In a message dated 3/3/2012 6:25:21 P.M. Eastern Standard Time,
nuckolls.bob(at)aeroelectric.com writes:
At 12:29 PM 3/3/2012, you wrote:
Hi David,
I agree with you on the type of battery you mention. Although, I don't
know anything about a $15 tender. If the electrolyte level gets low you can
have an explosion. How do I know that?!!
Let us consider the Odyssey Technical Manual which
may be downloaded from:
_http://www.odysseyfactory.com/documents/US-ODY-TM-001_0411_000.pdf
_ (http://www.odysseyfactory.com/documents/US-ODY-TM-001_0411_000.pdf)
First, I searched for the word "explosion" and didn't find
it.
Next I searched for the word "damage" and I find it
5 times. The word is used 4 times in the context of
mechanical damage to the battery or damage to surroundings
due to leakage.
________________________________________________________________________________
| From: | "Richard E. Tasker" <retasker(at)optonline.net> |
| Subject: | Re: Lowrance 2000C NMEA/DGPS Adapter cable NDC-2 |
Well, yeah, but if you translate from Norwegian the top yellow box says that this
product is no longer available...
Eric M. Jones wrote:
> --> AeroElectric-List message posted by: "Eric M. Jones"
>
> And maybe:
>
> http://www.marineshop.no/PartDetail.aspx?q=p:10516242
>
> --------
> Eric M. Jones
> www.PerihelionDesign.com
> 113 Brentwood Drive
> Southbridge, MA 01550
> (508) 764-2072
> emjones(at)charter.net
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=367710#367710
>
>
--
Please Note:
No trees were destroyed in the sending of this message. We do concede, however,
that a significant number of electrons may have been temporarily inconvenienced.
--
________________________________________________________________________________
| From: | David <ainut(at)knology.net> |
| Subject: | Re: battery chargers |
During charging, offgases are produced. If those gasses collect
somewhere, a spark can indeed set them off. Yes, thay can collect
inside the battery itself. Several RV batteries have been blown up that
way so I assume that it happens all over the place. Happened to me once
and my battery compartment is well ventilated.
David M.
Hopperdhh(at)aol.com wrote:
> Hi Bob,
> The explosion I mentioned was in reference to a flooded battery, not
> an Odyssey. I once put a charger on my tractor and forgot about it.
> A few weeks later I found part of the battery case about 10 feet from
> the tractor. The rest of the battery was still in the tractor battery
> box with the innards showing! I assume that when the electrolyte got
> below the top of the plates that some conductive debris shorted
> between them and set off the oxygen/hydrogen explosion. This
> experience has caused me to be leery of battery tenders. This could
> happen with even a 1/2 amp charger because the energy that makes the
> spark comes from the battery, not the charger.
> Thanks for the excellent information in your post on battery chargers.
> Dan
> RV-7A 766DH
> In a message dated 3/3/2012 6:25:21 P.M. Eastern Standard Time,
> nuckolls.bob(at)aeroelectric.com writes:
>
> At 12:29 PM 3/3/2012, you wrote:
> Hi David,
>
> I agree with you on the type of battery you mention. Although, I
> don't know anything about a $15 tender. If the electrolyte level
> gets low you can have an explosion. How do I know that?!!
>
> -------- Original Message --------
> Subject: Re: ACLU: 'Communism is the Goal'
> Date: Sat, 03 Mar 2012 20:14:49 -0900
> From: Storm <runedar(at)gci.net>
> To: ainut(at)knology.net
>
>
> Let us consider the Odyssey Technical Manual which
> may be downloaded from:
>
> http://www.odysseyfactory.com/documents/US-ODY-TM-001_0411_000.pdf
>
> First, I searched for the word "explosion" and didn't find
> it.
>
> Next I searched for the word "damage" and I find it
> 5 times. The word is used 4 times in the context of
> mechanical damage to the battery or damage to surroundings
> due to leakage.
>
________________________________________________________________________________
| From: | "David Lloyd" <skywagon(at)charter.net> |
| Subject: | Re: battery chargers |
Hi Dan,
I am wondering if the issue is confusing the design ideas of a "Tender
or Maintainer" with a garden variety battery charger of the small 0.5
amp (or less) varieties.
Tenders or Maintainers have a pre-set cut off voltage, then set
themselves to a set "float" voltage that is considerably lower than any
battery damage causing charge voltage. Even the tiny Harbor Freight
unit, usually on sale for less than $10, charges to a preset-'able'(*)
limit and then backs off to a float voltage. Once in the float voltage
mode they can be left on indefinitely on any good 12 v. battery.
The old fashion battery chargers, even the low amp units, must be taken
off line in a definite time period or they keep charging past their
labeled charge to usually the peak voltage of the rectified AC. It's
been a while since I thought about this number, but, I think it can go
to about 18 volts. So, case in point, a small 0.5 amp charger could
keep jamming current into an unattended battery until it got to 18
volts. Even, at a small 0.5 amps that battery is going to heat up, gas
out and otherwise possible due weird stuff. I can't see it exploding
without some other form of ignition but, it could certainly gas out and
become useless.....
Dave
(*) The cheap HF maintainers have inside the small plastic control box,
a circuit board mounted potentiometer. The back can be popped off the
box and the float voltage can be adjusted for custom settings. I like
about 13.1 v. for the float charging on 12v. batteries. CW lowers the
voltage and CCW raises it...
-------------------------------------------------------------------------
-------
----- Original Message -----
From: Hopperdhh(at)aol.com
To: aeroelectric-list(at)matronics.com
Sent: Sunday, March 04, 2012 5:41 AM
Subject: Re: AeroElectric-List: battery chargers
Hi Bob,
The explosion I mentioned was in reference to a flooded battery, not
an Odyssey. I once put a charger on my tractor and forgot about it. A
few weeks later I found part of the battery case about 10 feet from the
tractor. The rest of the battery was still in the tractor battery box
with the innards showing! I assume that when the electrolyte got below
the top of the plates that some conductive debris shorted between them
and set off the oxygen/hydrogen explosion. This experience has caused
me to be leery of battery tenders. This could happen with even a 1/2
amp charger because the energy that makes the spark comes from the
battery, not the charger.
Thanks for the excellent information in your post on battery chargers.
Dan
RV-7A 766DH
In a message dated 3/3/2012 6:25:21 P.M. Eastern Standard Time,
nuckolls.bob(at)aeroelectric.com writes:
At 12:29 PM 3/3/2012, you wrote:
Hi David,
I agree with you on the type of battery you mention. Although, I
don't know anything about a $15 tender. If the electrolyte level gets
low you can have an explosion. How do I know that?!!
Let us consider the Odyssey Technical Manual which
may be downloaded from:
http://www.odysseyfactory.com/documents/US-ODY-TM-001_0411_000.pdf
First, I searched for the word "explosion" and didn't find
it.
Next I searched for the word "damage" and I find it
5 times. The word is used 4 times in the context of
mechanical damage to the battery or damage to surroundings
due to leakage.
________________________________________________________________________________
| From: | "earl_schroeder(at)juno.com" <earl_schroeder(at)juno.com> |
| Subject: | Re: battery chargers |
Hi Dave,You wrote:"(*) The cheap HF maintainers have inside the small p
lastic control box, a circuit board mounted potentiometer. The back can
be popped off the box and the float voltage can be adjusted for custom
settings. I like about 13.1 v. for the float charging on 12v. batteries
. CW lowers the voltage and CCW raises it..." Unfortunately, the most r
ecent purchases I've made do NOT include the adjustable resistor you men
tioned. They have replaced the 'pot' with a fixed resistor.... One can
find the potentiometers at the usual places (on line) and I've replaced
several fixed resistors already. I've now switched from the HF varieties
to the Walmart ones discussed here. I have one per building and after
the most recent used battery is recharged, I just parallel it with the o
ther 12v batteries in that area. Works good for me! Earl
________________________________________________________________________________
| From: | "David Lloyd" <skywagon(at)charter.net> |
| Subject: | Re: battery chargers |
Earl,
Interesting that Harbor Freight's little unit has eliminated the pot.
I bought 6 of them last year at Oshkosh (super price) and they all have
pots. Guess I need to be careful with them.
Thanks,
Dave
-------------------------------------------------------------------------
-------
----- Original Message -----
From: earl_schroeder(at)juno.com
To: aeroelectric-list(at)matronics.com
Sent: Sunday, March 04, 2012 12:14 PM
Subject: Re: AeroElectric-List: battery chargers
Hi Dave,
You wrote:
"(*) The cheap HF maintainers have inside the small plastic control
box, a circuit board mounted potentiometer. The back can be popped off
the box and the float voltage can be adjusted for custom settings. I
like about 13.1 v. for the float charging on 12v. batteries. CW lowers
the voltage and CCW raises it..."
Unfortunately, the most recent purchases I've made do NOT include the
adjustable resistor you mentioned. They have replaced the 'pot' with a
fixed resistor....
One can find the potentiometers at the usual places (on line) and I've
replaced several fixed resistors already.
I've now switched from the HF varieties to the Walmart ones discussed
here. I have one per building and after the most recent used battery is
recharged, I just parallel it with the other 12v batteries in that area.
Works good for me!
Earl
________________________________________________________________________________
| From: | Hopperdhh(at)aol.com |
| Subject: | Re: battery chargers |
I didn't mean to confuse the issue.
My tractor battery that exploded was being charged by a simple 10 A
charger with just a transformer and diodes in it. It probably would not have
happened with a charger/tender/maintainer with some circuitry in it to limit
the float voltage to a reasonable value. My charger was probably putting
out a little current even after the battery charged up to 16 volts or more.
Not a good idea to leave it on charge for several weeks!! It was winter
time and I simply forgot all about it. Glad it wasn't my airplane!
My point was that it is possible to cause big problems if the circuit were
to fail and allow the voltage to go high enough long enough to lose the
electrolyte. Its a good idea to keep a check on the electrolyte level
(assuming a flooded battery) for that reason. I don't like the idea of leaving
the airplane in the hangar 8 miles away with no easy way to check on it
every day or two. Electronics is wonderful -- most of the time. I have
repaired a few pieces of made-in-China electronic junk that I wouldn't trust on
my airplane. I'm thinking of toys and Christmas lights/ornaments, etc. If
the workmanship on the battery tender is like that, forget it!
Dan
In a message dated 3/4/2012 1:16:27 P.M. Eastern Standard Time,
skywagon(at)charter.net writes:
Hi Dan,
I am wondering if the issue is confusing the design ideas of a "Tender or
Maintainer" with a garden variety battery charger of the small 0.5 amp (or
less) varieties.
Tenders or Maintainers have a pre-set cut off voltage, then set themselves
to a set "float" voltage that is considerably lower than any battery
damage causing charge voltage. Even the tiny Harbor Freight unit, usually on
sale for less than $10, charges to a preset-'able'(*) limit and then backs
off to a float voltage. Once in the float voltage mode they can be left on
indefinitely on any good 12 v. battery.
The old fashion battery chargers, even the low amp units, must be taken
off line in a definite time period or they keep charging past their labeled
charge to usually the peak voltage of the rectified AC. It's been a while
since I thought about this number, but, I think it can go to about 18 volts.
So, case in point, a small 0.5 amp charger could keep jamming current
into an unattended battery until it got to 18 volts. Even, at a small 0.5
amps that battery is going to heat up, gas out and otherwise possible due
weird stuff. I can't see it exploding without some other form of ignition but,
it could certainly gas out and become useless.....
Dave
(*) The cheap HF maintainers have inside the small plastic control box, a
circuit board mounted potentiometer. The back can be popped off the box
and the float voltage can be adjusted for custom settings. I like about
13.1 v. for the float charging on 12v. batteries. CW lowers the voltage and
CCW raises it...
____________________________________
----- Original Message -----
From: _Hopperdhh(at)aol.com_ (mailto:Hopperdhh(at)aol.com)
(mailto:aeroelectric-list(at)matronics.com)
Sent: Sunday, March 04, 2012 5:41 AM
Subject: Re: AeroElectric-List: battery chargers
Hi Bob,
The explosion I mentioned was in reference to a flooded battery, not an
Odyssey. I once put a charger on my tractor and forgot about it. A few
weeks later I found part of the battery case about 10 feet from the tractor.
The rest of the battery was still in the tractor battery box with the
innards showing! I assume that when the electrolyte got below the top of the
plates that some conductive debris shorted between them and set off the
oxygen/hydrogen explosion. This experience has caused me to be leery of battery
tenders. This could happen with even a 1/2 amp charger because the energy
that makes the spark comes from the battery, not the charger.
Thanks for the excellent information in your post on battery chargers.
Dan
RV-7A 766DH
In a message dated 3/3/2012 6:25:21 P.M. Eastern Standard Time,
nuckolls.bob(at)aeroelectric.com writes:
At 12:29 PM 3/3/2012, you wrote:
Hi David,
I agree with you on the type of battery you mention. Although, I don't
know anything about a $15 tender. If the electrolyte level gets low you can
have an explosion. How do I know that?!!
Let us consider the Odyssey Technical Manual which
may be downloaded from:
_http://www.odysseyfactory.com/documents/US-ODY-TM-001_0411_000.pdf
_ (http://www.odysseyfactory.com/documents/US-ODY-TM-001_0411_000.pdf)
First, I searched for the word "explosion" and didn't find
it.
Next I searched for the word "damage" and I find it
5 times. The word is used 4 times in the context of
mechanical damage to the battery or damage to surroundings
due to leakage.
href="http://www.matronics.com/Navigator?AeroElectric-List">http://www.matronics.com/Navigator?AeroElectric-List
href="http://forums.matronics.com">http://forums.matronics.com
href="http://www.matronics.com/contribution">http://www.matronics.com/c
(http://www.matronics.com/Navigator?AeroElectric-List)
(http://www.matronics.com/contribution)
________________________________________________________________________________
| Subject: | Burnouts Arbitrary? |
Good point. Yes, but it is not connected to the GMA 340. It was about 30 F outside
when this happened with plenty of cool air coming in. I do not have a cabin
heater.
Thanks,
Glenn
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Ed Gilroy
Sent: Saturday, March 03, 2012 4:15 PM
Subject: Re: AeroElectric-List: Burnouts Arbitrary?
Is your avionics fan working? Lost a Garmin GPS to that a few years back.
Sent from my iPhone
On Mar 3, 2012, at 10:36 AM, wrote:
> I have a Garmin 340 which burned up a main board a few weeks ago. Garmin gave
no particular excuse for the failure, so I thought Id throw out the question.
>
> - Is it common for Audio Panels to self destruct? Mine is about 8 years
old and worked normally up to the minute it failed.
> - The repair was flat rate at $600.00 so I dont want to throw it back
in and have it go up in smoke again.
> - Any tests I can perform? I am using 5 amp ATC fuse(s) for power. I
believe that is the recommended size.
> - The audio cables are custom built from Approach Fast Stack and have
not been altered since new.
>
>
> Thanks for the ideas.
>
> Glenn
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> 0
> t
>
>
===================================
===================================
===================================
===================================
>
________________________________________________________________________________
| Subject: | Burnouts Arbitrary? |
Thanks Bob,
I did not open it up before it went to the shop. Garmin indicated they replaced
the main board in the process. They provided no explanation. I re-installed today
and grounded the case to the grounding forest. I will try a lower fuse size
to see if that creates activity. I never smelled or saw smoke of any sort.
Glenn
-----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
Sent: Saturday, March 03, 2012 11:10 AM
Subject: Re: AeroElectric-List: Burnouts Arbitrary?
At 09:36 AM 3/3/2012, you wrote:
>I have a Garmin 340 which burned up a main board a few weeks ago.
>Garmin gave no particular excuse for the failure, so I thought I'd
>throw out the question.
>
>- Is it common for Audio Panels to self destruct? Mine is
>about 8 years old and worked normally up to the minute it failed.
No
>- The repair was flat rate at $600.00 so I don't want to
>throw it back in and have it go up in smoke again.
Did it actually 'smoke' . . . or at least smell bad?
>- Any tests I can perform? I am using 5 amp ATC fuse(s) for
>power. I believe that is the recommended size.
Sure, testing with a small fuse is one useful technique. I
use a current limited power supply for similar explorations.
You can set the short circuit current to any level from a
few milliamps up to full output from the supply. Let's you
explore a circuit's power management condition with little
risk of subjecting it to further damage.
Have you had it open? Can you see any char or signs of
overheating? A experienced bench technician can do the
sniff test and tell whether it's a component or burned
trace .. . but if it's a burned trace . . . it will be
obvious. Smoked integrated circuits can be hard to spot
sometimes.
Bob . . .
________________________________________________________________________________
| From: | <sam.marlow(at)roadrunner.com> |
| Subject: | Coolie Hat Switch |
Does anyone have a source for a roll your own coolie hat switch?
________________________________________________________________________________
| Subject: | Re: Coolie Hat Switch |
| From: | Etienne Phillips <etienne.phillips(at)gmail.com> |
**On 5 March 2012 06:50, wrote:
>
> Does anyone have a source for a roll your own coolie hat switch?
>
Hi Sam
Not cheap, but available from RS Components...
*http://tinyurl.com/6u8ephu
*
Hope that helps!
Etienne*
*
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Coolie Hat Switch |
At 10:50 PM 3/4/2012, you wrote:
>
>Does anyone have a source for a roll your own coolie hat switch?
I would think you'd need access to some
pretty good machine tools and a good bit
of patience. Not sure DIY is very cost
effetive.
Ray-Allen has one
http://www.rayallencompany.com/products/switches.html
Bob . . .
////
(o o)
===========o00o=(_)=o00o========
< Go ahead, make my day . . . >
< show me where I'm wrong. >
================================
________________________________________________________________________________
| From: | "Peter Mather" <peter(at)mather.com> |
| Subject: | Coolie Hat Switch |
Cheapest way of getting one is using an electric wing mirror switch from a car
breakers or ebay
________________________________________________________________________________
| From: | Buckley William <hoverandwire(at)yahoo.com> |
| Subject: | Coolie Hat Switch |
Take a look at these from Digikey ($22.50 each)
http://search.digikey.com/us/en/products/500-526/679-2289-ND/2063280
William B.
--- On Sun, 3/4/12, sam.marlow(at)roadrunner.com wrote:
> From: sam.marlow(at)roadrunner.com <sam.marlow(at)roadrunner.com>
> Subject: AeroElectric-List: Coolie Hat Switch
> To: "aeroelectric-list(at)matronics.com"
> Date: Sunday, March 4, 2012, 11:50 PM
> --> AeroElectric-List message
> posted by:
>
> Does anyone have a source for a roll your own coolie hat
> switch?
>
> AeroElectric-List Email Forum -
> - MATRONICS WEB FORUMS -
> List Contribution Web Site -
> -Matt
> Dralle, List Admin.
>
>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: battery chargers |
At 07:41 AM 3/4/2012, you wrote:
>
>Hi Bob,
>
>The explosion I mentioned was in reference to a flooded battery, not
>an Odyssey. I once put a charger on my tractor and forgot about
>it. A few weeks later I found part of the battery case about 10
>feet from the tractor. The rest of the battery was still in the
>tractor battery box with the innards showing! I assume that when
>the electrolyte got below the top of the plates that some conductive
>debris shorted between them and set off the oxygen/hydrogen
>explosion. This experience has caused me to be leery of battery
>tenders. This could happen with even a 1/2 amp charger because the
>energy that makes the spark comes from the battery, not the charger.
>
>Thanks for the excellent information in your post on battery chargers.
Oh yeah . . . I've seen flooded batteries do a
steam explosion . . . or more like a volcano
eruption too. A good friend of mine worked in
the Naval Battery Labs at Crane, IN. Those
labs are a kind of battery-hell. Many folks
(especially submariners) wont qualify a battery
until Crane sez, "they can't blow it up."
She sent me some videos of some rather spectacular
'batterycides'.
I am aware of only one in-service RG battery explosion.
It was a new model Concorde being qualified onto
a GA jet. This particular battery had been subjected to some
severe conditions of overcharging followed by
a couple of spool-ups (no ignition or fuel) on
the airplane. The evolved gasses combined with
some simulated balked starts fused a cross-over
joint between cells . . .
Emacs!
Concorde's crossovers are soldered on by hand . . .
Emacs!
. . . and set high enough on the cell wall to become immersed in
epoxy encapsulant which is used to fill the inter-cell sealing
channels in the lid . . .
Emacs!
Interestingly enough, this battery design had already been
qualified to the RTCA/TSO requirements . . . which seem not
to stress a battery as hard as in the incident aircraft.
Even though analysis of the event said it was not necessary,
Concorde did beef up the inter-cell connectors in that model
of battery.
We have been apprised of an incidence of a high-energy,
internal event on a Hawker 10 AH 24V battery . . .
Emacs!
Temperatures were so high as to severely char the internals
Emacs!
. . . I think this event stayed inside the battery case except
for one small hole.
I wasn't informed of the history of this even but given the
battery's small size (10 a.h.) and the size of the typical
24v alternator (60A) I'm betting that the short term high
recharge rates for this battery were exceeded causing
a failure of the one cell.
The RG or SVLA battery has amassed a long history of
robust service and few exceptions for more than benign
failures . . . and they get better all the time.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Coolie Hat Switch |
At 03:42 PM 3/5/2012, you wrote:
>
>
>Take a look at these from Digikey ($22.50 each)
>
>http://search.digikey.com/us/en/products/500-526/679-2289-ND/2063280
Cool find Bill . . . these are electrically 'delicate'
switches. Rated 1 to 50 mA. They should be used to control
a solid-state buffered relay deck but they look pretty
slick.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: battery chargers |
At 11:40 AM 3/4/2012, you wrote:
>
>During charging, offgases are produced. If those gasses collect
>somewhere, a spark can indeed set them off. Yes, thay can collect
>inside the battery itself. Several RV batteries have been blown up
>that way so I assume that it happens all over the place. Happened
>to me once and my battery compartment is well ventilated.
>
>David M,
Was there any sort of failure analysis done? Pictures
taken? An RG battery stressed so hard as to produce
gasses not contained in the mats combined with some
spark-producing condition begs for answers as to root
cause. I would be reluctant to assume that it 'happens
all over the place' . . . yours is the first mention
of explosive de-construction of a battery here on
the List in many years.
I was aware of a battery box explosion in a GlasAir
wherein the battery box provided containment and
a battery contactor provided ignition. But even that
event was poorly documented and no mention was made
of what was probably a sustained OV event that cooked
the battery.
Somebody sent me an abused Odyssey some years back,
Dec 2005 I think. I sent it to Concorde and their guys
tore it down for closer examination.
In this case, the battery case was intact. The battery had
be subject to an OV condition which heated the battery up
while building large sulfation crystals on the normally thin
plates. The thing puffed up like a guppy.
Emacs!
Emacs!
RG batteries are not designed to withstand severe over-charging
or extra-ordinary stress such as that which produced the
one real explosion I'm aware of. After running the gauntlets at
TSO or Naval qualification labs, they are shown to offer benign
failure events when used in a system with legacy attention paid to
rapid mitigation of an OV event.
If anyone becomes aware of what appears to have been an explosive
rupture of an RG battery, please let me know about it ASAP. I'll
pay for pictures, a narrative of conditions leading up to the event
and pay the shipping for the carcass. These things need to be
examined by folks who are very good at it so as to broaden our
understanding and improvement on the best we know how to do.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
Had a meeting today that promises to renew a
relationship with folks at National Institute
of Aviation Research (NIAR) on the campus of
Wichita State University.
They are the proud possessors and operators of
an extensive and up-to-date EMC lab. Guys I used
to work with at HBC are now at NIAR. I'll be looking
for an opportunity to get a radio-peek at the two exemplar
HID lamps I've been provided. We'll do conducted emissions
on the power supply wires in addition to a probing
exploration of light's noises on a spectrum analyzer.
Watch this space . . .
Bob . . .
________________________________________________________________________________
| From: | Charles Brame <chasb(at)satx.rr.com> |
| Subject: | Re-juvinate a NiCad Battery? |
Is there anyway to rejuvenate an old NiCad battery? I have an iCOM
hand held radio with a rechargeable battery pack. I assume the battery
is a NiCad. The radio requires a 9.6v charge, but I can't get the pack
charged above 9.25v. At that level I can listen to the radio, but
cannot transmit. The charger that came with the radio puts out 10.4v
when hooked to the battery, but the battery voltage won't increase
even after a day or so of recharging. Is there any way to save this
battery pack?
Charlie Brame
RV-6A N11CB
San Antonio
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Re-juvinate a NiCad Battery? |
At 02:37 AM 3/6/2012, you wrote:
>
>Is there anyway to rejuvenate an old NiCad battery? I have an iCOM
>hand held radio with a rechargeable battery pack. I assume the battery
>is a NiCad. The radio requires a 9.6v charge, but I can't get the pack
>charged above 9.25v. At that level I can listen to the radio, but
>cannot transmit. The charger that came with the radio puts out 10.4v
>when hooked to the battery, but the battery voltage won't increase
>even after a day or so of recharging. Is there any way to save this
>battery pack?
>
>Charlie Brame
>RV-6A N11CB
>San Antonio
Yes . . . maybe . . . and perhaps no. NiCads can suffer
certain degrading of chemistry that prevents any recovery.
Some 'failed' batteries have grown whisker-shorts in
the cells that MIGHT yield to a low voltage impulse
of many amps. For example, if you have access to a single
2 volt lead-acid cell or even another FAT ni-cad cell,
connecting it in parallel with the suspect whisker-short
might fuse it and recover the cell's utility.
The best advise I can offer is to re-cell your battery
pack. There are battery re-build companies that do this
quite well. Your battery pack is probably an array of
AA sized cells which you can purchase with solder tabs
from places like:
http://tinyurl.com/74c2x27
http://tinyurl.com/899bjcu
Bob . . .
________________________________________________________________________________
| From: | ronburnett(at)charter.net |
| Subject: | Re-juvinate a NiCad Battery? |
You might take the battery to Wholesale Batts. to see what they have for
a replacement. I did that for a radio battery for my Luscombe that has
no elect. system. I had to modify the length of the case that held the
batt. but for less than $20 I have a much better system that I can
recharge. The old one quit recharging.
Good luck,
Ron Burnett
On Tue, Mar 6, 2012 at 2:37 AM, Charles Brame wrote:
>
>
> Is there anyway to rejuvenate an old NiCad battery? I have an iCOM
> hand held radio with a rechargeable battery pack. I assume the battery
> is a NiCad. The radio requires a 9.6v charge, but I can't get the pack
> charged above 9.25v. At that level I can listen to the radio, but
> cannot transmit. The charger that came with the radio puts out 10.4v
> when hooked to the battery, but the battery voltage won't increase
> even after a day or so of recharging. Is there any way to save this
> battery pack?
>
> Charlie Brame
> RV-6A N11CB
> San Antonio
>
________________________________________________________________________________
| From: | Michael Welch <mdnanwelch7(at)hotmail.com> |
| Subject: | Re-juvinate a NiCad Battery? |
Charlie,
I also have an Icom handheld radio. Years ago, when my Icom A22 ni-cad OEM battery
pack died, I bought their
(expensive) AA battery holder (now they're half price). It comes empty, and you
simply use 10 of your rechargeable generic
AA batteries. In fact, you can use AA ni-cads, or AA NiMHs, or plain old Duracells.
It's just an empty compartment,
and you fill it up with 10 rechargeable AA batteries.
For years I've just used the 1.2 volt NiMH's I got off of eBay. A couple of
years ago, I bought the new rechargeable
1.5 volts models, although it worked just fine on the (10) 1.2 volt versions.
Here is the container for the A22. I would imagine you could get one of these
for all their handheld models, although I haven't looked.
(you didn't mention what model you have)
http://www.ebay.com/itm/CM-167-10-AA-Cell-Battery-Case-ICOM-Air-Band-IC-A3-IC-A3E-IC-A22-IC-A22E-/160650004281
?pt=LH_DefaultDomain_0&hash=item25677c8739#ht_3307wt_1063
Mike Welch
> At 02:37 AM 3/6/2012, you wrote:
>>
>> Is there anyway to rejuvenate an old NiCad battery? I have an iCOM
>> hand held radio with a rechargeable battery pack. I assume the battery
>> is a NiCad. The radio requires a 9.6v charge, but I can't get the pack
>> charged above 9.25v. At that level I can listen to the radio, but
>> cannot transmit. The charger that came with the radio puts out 10.4v
>> when hooked to the battery, but the battery voltage won't increase
>> even after a day or so of recharging. Is there any way to save this
>> battery pack?
>>
>> Charlie Brame
>> RV-6A N11CB
>> San Antonio
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: OT: Old electronics info. |
At 09:23 PM 3/5/2012, you wrote:
>
>Greetings,
>
>I have an Acme Voltrol type T-2-1404 variable transformer I'm using
>to set up a power supply for my bench. Can anyone tell me where I
>can get the max Amps or VA rating for it?
What are the physical dimensions of this device?
>I also have a big red rectifier that is about a 6" cube of fins
Sounds like a selenium rectifier . . .
http://en.wikipedia.org/wiki/Selenium_rectifier
Certainly something you'd want to replace with
a silicon bridge rectifier.
> and an inductor that is the size of a softball and
> weighs >10lb. Neither have any identifying marks on them.
The inductor would be used in concert with one or more
capacitors to smooth the full-wave rectified DC output
current.
How would you want to use this supply? Variable transformers
are auto-transformers that generally deliver 0-100% or perhaps
135% of input voltage depending on how they are wired. The
have output wires in common with the input wires. In other words
they are not isolated from the AC line . . . so there are potential
shock hazards to consider when using these as the sole controlling
device for variable voltage. Further, unless you need to do testing
at voltages above 14 or 28 volts, you would not be able to use
much of the transformer's dynamic range.
You would probably want to use the variable transformer to
drive a 120 to 12 or 24 volt transformer. This will make
better use of the variable transformer's utility and
possibly get you more current capability too.
Getting smooth DC is another problem. You can probably
use the inductor you have and add some capacitors . . .
but you're going to find that the output voltage is
very poorly regulated with respect to changing loads.
Suggest you consider an electronically regulated
bench power supply like:
Emacs!
Devices like this will give you stable, current limited,
smooth and very adjustable output. This one is $75 off
of ebay. You might be able to sell your venerable
components and cover much of the cost a supply like this.
I have 5 such supplies here in shop ranging in output
from 200 Ma to 50 amps. They're invaluable tools when
they perform well . . . I'm pretty sure that after you
spend the time hammering a supply together using the
parts you have, you'll be disappointed in the performance.
I have one variable transformer controlled supply. It's
for providing low current, 0-500 volts dc for some vacuum
tube work I was doing years ago. Haven't used it in years
but I'll be showing it (and the vacuum tubes) to my grandsons.
Bob . . .
________________________________________________________________________________
| From: | rayj <raymondj(at)frontiernet.net> |
| Subject: | Re: OT: Old electronics info. |
Bob,
I think you correct in identifying the rectifier.
The Voltrol is about 4x4x8. It has 2 ranges covering 0-140 V. Weighs
about 20 lb.
It was originally set up with 2 50V caps and the inductor.
I have it breadboarded with a bridge rectifier and cap/resistor filter.
I have some projects which require 50-90 V DC and 10-15 amps. I don't
think the Voltrol will pass more than about 5 amps based on the size of
the wire on the windings. But I'd rather know than guess.
How critical is the matching of the inductor with a pair of caps to use
as filter, similar to the one that was originally used? Of course I
would use caps with high enough voltage ratings. I'm willing to deal
with the poor filtering to get the utility for little $. Might even
consider building a regulating circuit at a later time.
I have a couple of Heathkit regulated power supplies for most of the
electronic bench work.
One other question. I have a couple of Simpson amp meters, the one's
that are about 3" in diameter. One ac and one dc. Are those designed to
be wired in series with the load, or do they need a shunt of some sort?
Unfortunately I didn't pay close attention when I salvaged these.
I regret having to take time on the list, but I've spent hours on the
net without any success.
Thanks for taking time to share your knowledge.
Raymond Julian
Kettle River, MN
"And you know that I could have me a million more friends,
and all I'd have to lose is my point of view." - John Prine
On 03/06/2012 10:38 AM, Robert L. Nuckolls, III wrote:
> At 09:23 PM 3/5/2012, you wrote:
>>
>> Greetings,
>>
>> I have an Acme Voltrol type T-2-1404 variable transformer I'm using to
>> set up a power supply for my bench. Can anyone tell me where I can get
>> the max Amps or VA rating for it?
>
> What are the physical dimensions of this device?
>
>
>> I also have a big red rectifier that is about a 6" cube of fins
>
>
> Sounds like a selenium rectifier . . .
>
> http://en.wikipedia.org/wiki/Selenium_rectifier
>
>
> Certainly something you'd want to replace with
> a silicon bridge rectifier.
>
>> and an inductor that is the size of a softball and weighs >10lb.
>> Neither have any identifying marks on them.
>
> The inductor would be used in concert with one or more
> capacitors to smooth the full-wave rectified DC output
> current.
>
> How would you want to use this supply? Variable transformers
> are auto-transformers that generally deliver 0-100% or perhaps
> 135% of input voltage depending on how they are wired. The
> have output wires in common with the input wires. In other words
> they are not isolated from the AC line . . . so there are potential
> shock hazards to consider when using these as the sole controlling
> device for variable voltage. Further, unless you need to do testing
> at voltages above 14 or 28 volts, you would not be able to use
> much of the transformer's dynamic range.
>
> You would probably want to use the variable transformer to
> drive a 120 to 12 or 24 volt transformer. This will make
> better use of the variable transformer's utility and
> possibly get you more current capability too.
>
> Getting smooth DC is another problem. You can probably
> use the inductor you have and add some capacitors . . .
> but you're going to find that the output voltage is
> very poorly regulated with respect to changing loads.
>
> Suggest you consider an electronically regulated
> bench power supply like:
>
> Emacs!
>
> Devices like this will give you stable, current limited,
> smooth and very adjustable output. This one is $75 off
> of ebay. You might be able to sell your venerable
> components and cover much of the cost a supply like this.
>
> I have 5 such supplies here in shop ranging in output
> from 200 Ma to 50 amps. They're invaluable tools when
> they perform well . . . I'm pretty sure that after you
> spend the time hammering a supply together using the
> parts you have, you'll be disappointed in the performance.
>
> I have one variable transformer controlled supply. It's
> for providing low current, 0-500 volts dc for some vacuum
> tube work I was doing years ago. Haven't used it in years
> but I'll be showing it (and the vacuum tubes) to my grandsons.
>
> Bob . . .
>
________________________________________________________________________________
| From: | "David Lloyd" <skywagon(at)charter.net> |
| Subject: | Re: Re-juvinate a NiCad Battery? |
Mike,
Great tip for the Icom A-22..Thanks.
David
PS: I do not know any way to rejuvenate an aged, encapsulated NiCad
'battery' pack. If one has surgical skills and can cut the pack apart, then
you can find and toss the offending cell(s). By that time, it would make
more sense to toss them all and start with all fresh. Still a big job for
encapsulated type batteries....
___________________________________________________________________
----- Original Message -----
From: "Michael Welch" <mdnanwelch7(at)hotmail.com>
Sent: Tuesday, March 06, 2012 7:28 AM
Subject: AeroElectric-List: Re-juvinate a NiCad Battery?
>
>
> Charlie,
>
> I also have an Icom handheld radio. Years ago, when my Icom A22 ni-cad
> OEM battery pack died, I bought their
> (expensive) AA battery holder (now they're half price). It comes empty,
> and you simply use 10 of your rechargeable generic
> AA batteries. In fact, you can use AA ni-cads, or AA NiMHs, or plain old
> Duracells. It's just an empty compartment,
> and you fill it up with 10 rechargeable AA batteries.
>
> For years I've just used the 1.2 volt NiMH's I got off of eBay. A couple
> of years ago, I bought the new rechargeable
> 1.5 volts models, although it worked just fine on the (10) 1.2 volt
> versions.
>
> Here is the container for the A22. I would imagine you could get one of
> these for all their handheld models, although I haven't looked.
> (you didn't mention what model you have)
>
> http://www.ebay.com/itm/CM-167-10-AA-Cell-Battery-Case-ICOM-Air-Band-IC-A3-IC-A3E-IC-A22-IC-A22E-/160650004281
> ?pt=LH_DefaultDomain_0&hash=item25677c8739#ht_3307wt_1063
>
>
> Mike Welch
>
>
>> At 02:37 AM 3/6/2012, you wrote:
>>>
>>>
>>> Is there anyway to rejuvenate an old NiCad battery? I have an iCOM
>>> hand held radio with a rechargeable battery pack. I assume the battery
>>> is a NiCad. The radio requires a 9.6v charge, but I can't get the pack
>>> charged above 9.25v. At that level I can listen to the radio, but
>>> cannot transmit. The charger that came with the radio puts out 10.4v
>>> when hooked to the battery, but the battery voltage won't increase
>>> even after a day or so of recharging. Is there any way to save this
>>> battery pack?
>>>
>>> Charlie Brame
>>> RV-6A N11CB
>>> San Antonio
>
>
>
________________________________________________________________________________
| From: | Charlie England <ceengland(at)bellsouth.net> |
| Subject: | Re: Re-juvinate a NiCad Battery? |
February 05, 2012 - March 06, 2012
AeroElectric-Archive.digest.vol-kw