Today's Message Index:
----------------------
1. 04:22 AM - Dual bus VM-1000 (Treff, Arthur)
2. 04:23 AM - Noise in the headset troubleshooting (long) (Treff, Arthur)
3. 08:30 AM - Re: Noise in the headset troubleshooting (long) (William Mills)
4. 12:13 PM - Re: Noise in the headset troubleshooting (long) (Doug Dodson)
5. 12:51 PM - music input jacks (Dan Checkoway)
6. 06:40 PM - Re: music input jacks (Charlie & Tupper England)
7. 08:14 PM - ACK ELT control wire? (BAKEROCB@aol.com)
8. 09:09 PM - alternator (Tom Reading)
Message 1
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Dual bus VM-1000 |
--> AeroElectric-List message posted by: "Treff, Arthur" <Arthur.Treff@Smartm.com>
Bob,
Thanks for your research on my behalf. It was definately above and beyond the
call of duty. You should be inducted into the EAA hall of fame. Not only did
you go the extra mile and contact Vision Mirco, but you generated a schematic.
None of the drawings for my plane look as good as yours. Anyway, thanks again
for your tireless efforts.
Art Treff
RV-8 Fastback in progress
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Noise in the headset troubleshooting (long) |
--> AeroElectric-List message posted by: "Treff, Arthur" <Arthur.Treff@Smartm.com>
Listers,
I wanted to share with you some recent events surrounding troubleshooting 'noisy
radio' problems in my 1966 Mooney, just in case this ever happens to you. The
electrical system is standard "store bought" with battery on the firewall,
60A PMA'd alternator with external Zeftronics VR with on board over voltage protection.
The output of the alt goest thru the firewall to the bus bar. (NFG).
Gage is battery ammeter and I monitor bus voltage via a feature on the Stormscope.
Regulator has 800 hours on it, and the alternator is a rebuilt with
approx 50 hours.
The scenario:
Over time, I have noticed two abberations in my plane, I have treated them as unrelated.
Here's the setup.
Every once in awhile in flight, particularly at high altitudes. I notice a slight
noise in the headset that sounds like frying bacon. It is intermittent. I
further notice that if I turn on a high load device like a landing light (250W)
the noise goes away. So, historically, I have suspected that this has something
to do with the VR, but I do nothing about it, as it's intermittent.
Additionally, Every once in awhile ATC tells me my KX-155 is totally unreadable.
I switch to the UPS GX60 and they say it's better, but not perfect. The King
is as old as they get, and it usually has to go into the shop at least every
other year, so I really do nothing about it. I'm thinking that perhaps it's
getting too hot, so I usually turn it off, and xmit on the GPS comm. Why that's
not as clear, I usually rationalize that it's an inferior radio, or antenna,
or less power than the King's 10 watts.
The scenario worsens.
Last month, the 'frying bacon' noise worsened. It was louder in the headset, and
loading up the alternator with Pitot heat and landing light lessened the volume
but did not erradicate it. I fly legs of 3-5 hours so I have alot of time
to listen and wonder. Shutting off the audio panel made the sound go away.
Hmmm.....perhaps the PS Engineering unit is starting to go... or perhaps I got
some Corrosion X into critical places in antenna wiring during my annual last
month...I also had more calls from ATC asking me to switch to another radio
than the King. So, I was thinking that the KX-155 needed to go into the shop
as did the audio panel, this can't be the voltage regulator. (not so fast, silly
boy).
Total chaos.
Last week, during climb out on a routine 190 mile trip, the noise in the headset
was really bad, and my ability to hear radio xmissions was diminished. ATC
did not like my radios at all. I was on an IFR plan, but it was VMC so I pressed
on. I tried loading up the bus, to get rid of the noise, but this no longer
helped. I shut off the audio panel and all this did was make the noise softer.
Finally, my eyes alighted on the voltage monitor. It read 11.2 volts!
The ammeter showed a slight discharge. No alternator. I pulled the 5A alt field
CB and all quieted in the headset. Ah ha! Gotcha you little bugger. A bad
somethingorother in the alt circuit. I pressed the field breaker back in and
the alt came back on line, voltge came back up to 13.8, the battery was drawing
a charge on the ammeter and the noise quieted down, but was not gone. Now
is when I really started troubleshooting. Every time I pulled the field breaker,
the noise totally died away. I happen to have a spare VR with me (I'm not
so organized usually) and the connector is accessible from under the panel.
I shut off everything except one radio, pulled the field breaker. I reached
under, found the connector and plugged in the new regulator. I reset the field
breaker, in eager anticipation of a nice fat charge, quite in the earphones
and a charging battery. I was convinced that the problem was the VR. What happened
surpriese me: the new regulator lighted the OV light, and popped off line!
OK, so a bad alternator I thought, could it be intermittently shorts in
the field, diodes, what?
The solution.
On the ramp, I pulled the side cowling and wiggled the alt terminal connections.
The field ring terminal was tight on the post, but the whole post was loose!
I wiggled the other post (goes to ground) and it too was loose as well. So
much for "Gen-U-Wine FAA repair stations, yellow tags saying Return to Service
and PMA's parts." This was a newly overhauled alternator, with approx 50 hours
on it over 3 months. I took off the ring terms, tightened down the jam nuts
on the terminal posts and reinstalled the field and ground ring terminals respectively.
My sceptical self did not really thing that this could be the cause
of the entire episode, but my return flight was the quietest I've had in a
long time, no complaints from ATC re: the King radio's quality and best of all
no frying bacon at all, not a trace.
The lesson, FWIW.
What started out as a radio annoyance turned out to be a mechanical problem on
the alternator. The radio and audio noise, as it turns out, were the best troubleshooting
tools at my disposal. Better that than total alternator failure
in the goo at night. In the future, I will not take changes in headset noise
lightly. It could be trying to tell me something.
Art Treff
RV-8 Fastback interior work.
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Noise in the headset troubleshooting (long) |
--> AeroElectric-List message posted by: William Mills <courierboy@earthlink.net>
>--> AeroElectric-List message posted by: "Treff, Arthur"
><Arthur.Treff@Smartm.com>
>
>Listers,
-----------snip-------------
>The lesson, FWIW.
>What started out as a radio annoyance turned out to be a mechanical
>problem on the alternator.
----------snip------------
>Art Treff
>RV-8 Fastback interior work.
Art -
Nice write-up.
It drives home the importance of becoming intimate with a plane by
feeling all its parts! I often find that problems with electrical
systems are mechanical in nature (not "bad diodes" as we'd jokingly
say).
Good on ya for finding and fixing this without throwing parts at it.
Thank you -
Bill Mills
RANS Courier in progress
SF bay area, Calif.
P.S.
Our A&P school instructor, Huston "Buck" Choate, would inspect an
airplane with the usual flashlight and mirror but emphasized touching
everything in sight and giving it a squeeze, tug, jiggle, etc. I'd
never seen anything like this but over time I realize he was teaching
us a most valuable lesson.
Do not archive
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Noise in the headset troubleshooting (long) |
--> AeroElectric-List message posted by: "Doug Dodson" <dodsond@qnet.com>
Same airplane (1966 M20C), with an InterAv alternator conversion. Worked
perfectly for a year then started to get the occasional noise problem just
as Arthur did. Similar trouble shooting sequence (but without the spare
VR). Got slowly worse over time then my JPI started showing the low voltage
conditon, intermittantly and infrequently at first then more frequently. I
check all the connections several times. Fix came when one day I decided to
just unwrap all the wiring from the harnesses and start checking splices and
I discovered that the crimp had gone bad on the ring terminal where the
field wire attaches to the alternator. That was the first thing I had
checked in previous attempts and I checked it on several occasions. I
didn't discover it sooner because all I really checked was that the nut held
the terminal on the post well (post was solid). I had done such a good job
with the heat shrink that the mechanical connection was pretty good but of
course, not THAT good. First good tug it came right out of the crimp. 10
minutes later with a new ring terminial from my bench stock and my ratchet
crimpers... problem fixed. Execellent electrics for 3 years and 600 hours
now.
Douglas L. Dodson, Jr.
Glasair II-S FT
Flight Test Engineer, CFI-A,I,G
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Treff,
Arthur
Subject: AeroElectric-List: Noise in the headset troubleshooting (long)
--> AeroElectric-List message posted by: "Treff, Arthur"
<Arthur.Treff@Smartm.com>
Listers,
I wanted to share with you some recent events surrounding troubleshooting
'noisy radio' problems in my 1966 Mooney, just in case this ever happens to
you. The electrical system is standard "store bought" with battery on the
firewall, 60A PMA'd alternator with external Zeftronics VR with on board
over voltage protection. The output of the alt goest thru the firewall to
the bus bar. (NFG). Gage is battery ammeter and I monitor bus voltage via
a feature on the Stormscope. Regulator has 800 hours on it, and the
alternator is a rebuilt with approx 50 hours.
The scenario:
Over time, I have noticed two abberations in my plane, I have treated them
as unrelated. Here's the setup.
Every once in awhile in flight, particularly at high altitudes. I notice a
slight noise in the headset that sounds like frying bacon. It is
intermittent. I further notice that if I turn on a high load device like a
landing light (250W) the noise goes away. So, historically, I have
suspected that this has something to do with the VR, but I do nothing about
it, as it's intermittent.
Additionally, Every once in awhile ATC tells me my KX-155 is totally
unreadable. I switch to the UPS GX60 and they say it's better, but not
perfect. The King is as old as they get, and it usually has to go into the
shop at least every other year, so I really do nothing about it. I'm
thinking that perhaps it's getting too hot, so I usually turn it off, and
xmit on the GPS comm. Why that's not as clear, I usually rationalize that
it's an inferior radio, or antenna, or less power than the King's 10 watts.
The scenario worsens.
Last month, the 'frying bacon' noise worsened. It was louder in the
headset, and loading up the alternator with Pitot heat and landing light
lessened the volume but did not erradicate it. I fly legs of 3-5 hours so I
have alot of time to listen and wonder. Shutting off the audio panel made
the sound go away. Hmmm.....perhaps the PS Engineering unit is starting to
go... or perhaps I got some Corrosion X into critical places in antenna
wiring during my annual last month...I also had more calls from ATC asking
me to switch to another radio than the King. So, I was thinking that the
KX-155 needed to go into the shop as did the audio panel, this can't be the
voltage regulator. (not so fast, silly boy).
Total chaos.
Last week, during climb out on a routine 190 mile trip, the noise in the
headset was really bad, and my ability to hear radio xmissions was
diminished. ATC did not like my radios at all. I was on an IFR plan, but
it was VMC so I pressed on. I tried loading up the bus, to get rid of the
noise, but this no longer helped. I shut off the audio panel and all this
did was make the noise softer. Finally, my eyes alighted on the voltage
monitor. It read 11.2 volts! The ammeter showed a slight discharge. No
alternator. I pulled the 5A alt field CB and all quieted in the headset.
Ah ha! Gotcha you little bugger. A bad somethingorother in the alt
circuit. I pressed the field breaker back in and the alt came back on line,
voltge came back up to 13.8, the battery was drawing a charge on the ammeter
and the noise quieted down, but was not gone. Now is when I really started
troubleshooting. Every time I pulled the field breaker, the noise totally
died away. I happen to have!
a spare VR with me (I'm not so organized usually) and the connector is
accessible from under the panel. I shut off everything except one radio,
pulled the field breaker. I reached under, found the connector and plugged
in the new regulator. I reset the field breaker, in eager anticipation of a
nice fat charge, quite in the earphones and a charging battery. I was
convinced that the problem was the VR. What happened surpriese me: the new
regulator lighted the OV light, and popped off line! OK, so a bad
alternator I thought, could it be intermittently shorts in the field,
diodes, what?
The solution.
On the ramp, I pulled the side cowling and wiggled the alt terminal
connections. The field ring terminal was tight on the post, but the whole
post was loose! I wiggled the other post (goes to ground) and it too was
loose as well. So much for "Gen-U-Wine FAA repair stations, yellow tags
saying Return to Service and PMA's parts." This was a newly overhauled
alternator, with approx 50 hours on it over 3 months. I took off the ring
terms, tightened down the jam nuts on the terminal posts and reinstalled the
field and ground ring terminals respectively. My sceptical self did not
really thing that this could be the cause of the entire episode, but my
return flight was the quietest I've had in a long time, no complaints from
ATC re: the King radio's quality and best of all no frying bacon at all, not
a trace.
The lesson, FWIW.
What started out as a radio annoyance turned out to be a mechanical problem
on the alternator. The radio and audio noise, as it turns out, were the
best troubleshooting tools at my disposal. Better that than total
alternator failure in the goo at night. In the future, I will not take
changes in headset noise lightly. It could be trying to tell me something.
Art Treff
RV-8 Fastback interior work.
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | music input jacks |
--> AeroElectric-List message posted by: "Dan Checkoway" <dan@rvproject.com>
Can somebody recommend a decent 1/8" stereo music input jack that can be
panel mounted and isolated from ground somehow? I'm just assuming that
keeping the audio return isolated from ground is ideal for reducing noise
induced in the system.
Are there insulating washers available, similar to those used on headset/mic
jacks, that can be used on smaller jacks?
Thanks in advance,
)_( Dan
RV-7 N714D
http://www.rvproject.com
Message 6
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: music input jacks |
--> AeroElectric-List message posted by: Charlie & Tupper England <cengland@netdoor.com>
Dan Checkoway wrote:
>--> AeroElectric-List message posted by: "Dan Checkoway" <dan@rvproject.com>
>
>Can somebody recommend a decent 1/8" stereo music input jack that can be
>panel mounted and isolated from ground somehow? I'm just assuming that
>keeping the audio return isolated from ground is ideal for reducing noise
>induced in the system.
>
>Are there insulating washers available, similar to those used on headset/mic
>jacks, that can be used on smaller jacks?
>
>Thanks in advance,
>)_( Dan
>RV-7 N714D
>http://www.rvproject.com
>
A Google search for 'miniature phone jack with isolated ground' yielded:
Stereo phone jack has isolated ground.
Designed for pc-board mounting, the CTP-310 and CTP-312 3.5-mm stereo
phone jacks offer optional grounded or isolated bushing and a life
expectancy of 5000 mating cycles. The mini-phone jacks can be used for
industrial, consumer, and computer multimedia sound cards, as well as
other applications requiring audio input and output. Unit price in
volume quantities is $0.20. Connect-Tech Products Inc, Carson City, NV.
(702) 883-0986.
not exactly what you want but a trip to their web site:
http://www.connect-tech-products.com/connectors/three_five/three_five_downloads/35mm.pdf
might get you what you want. CTP-354W-S1 looks like it would work, with
a couple of extra unneeded pins.
Switchcraft.com is another good bet, but their web site is being
stubborn tonight.
Charlie
Message 7
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | ACK ELT control wire? |
--> AeroElectric-List message posted by: BAKEROCB@aol.com
7/4/2003
Hello Russ Werner and Jerry Kaidor, Below is a copy of your postings a while
back on this subject. I am confronted with the same issue with an ACK ELT O1
regarding replacing the telephone style control wire extension.
But one issue remains unresolved. Russ says you must do some wire swapping
when putting on new connectors and Jerry says the cable works fine as purchased.
Can either one of you or both revisit this issue and tell me if I can use a
standard 4 wire telephone cable as purchased with connectors already installed
or if I'll have to buy connectors, do some wire swapping and crimp on the new
connectors?
Many thanks.
'OC' Baker, Builder of KIS TR-1 #116 4/14/97 - ?/?/?
<<Message: #7465 From: jerry@tr2.com Subject: Re: ELT control wire? Date:
Oct 24, 2002
Russ Werner wrote: "It's just telephone cable. Not critical by any means.
Buy the 25 footer and clip off the male end. Reinstall a new male end where
you need it and
be sure to swap wires accordingly, as the ELT wires cross enroute while the
telephone wires don't."
*** Thanks Russ. That's what I did. Actually, the 25-footer worked fine
as it was wired. I had to snip the connector and crimp on a new one anyway
to fish the wire through the floor. - Jerry>>
Message 8
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
--> AeroElectric-List message posted by: "Tom Reading" <treading@comcast.net>
Looking at the drawings it shows on the b+c the field wire goes from a
single terminal on the regulator but two terminals at the alt. I ran a small
link between the two then one wire back to the reg. Is this the right way.
Also I was wondering with the two alt. system will there be times when I
could or should run both of them at the same time?
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of
AeroElectric-List Digest Server
Subject: AeroElectric-List Digest: 13 Msgs - 07/01/03
*
==================================================
Online Versions of Today's List Digest Archive
==================================================
Today's complete AeroElectric-List Digest can be also be found in either
of the two Web Links listed below. The .html file includes the Digest
formatted in HTML for viewing with a web browser and features Hyperlinked
Indexes and Message Navigation. The .txt file includes the plain ASCII
version of the AeroElectric-List Digest and can be viewed with a generic
text editor such as Notepad or with a web browser.
HTML Version:
http://www.matronics.com/digest/aeroelectric-list/Digest.AeroElectric-List.2
003-07-01.html
Text Version:
http://www.matronics.com/digest/aeroelectric-list/Digest.AeroElectric-List.2
003-07-01.txt
================================================
EMail Version of Today's List Digest Archive
================================================
AeroElectric-List Digest Archive
---
Total Messages Posted Tue 07/01/03: 13
Today's Message Index:
----------------------
1. 06:48 AM - Problem with web page? (Robert L. Nuckolls, III)
2. 07:45 AM - Re: Problem with web page? (Freddie Freeloader)
3. 08:08 AM - Re: Problem with web page? (Bruce Gray)
4. 08:12 AM - Re: Problem with web page? (Bruce Gray)
5. 08:19 AM - KX-125 problem (Bruce Green)
6. 09:23 AM - Grounding questions (Bob Lee)
7. 12:22 PM - Re: KX-125 problem (Robert L. Nuckolls, III)
8. 02:27 PM - Re: KX-125 problem (Bruce Green)
9. 04:00 PM - Re: KX-125 problem (Robert L. Nuckolls, III)
10. 04:08 PM - Re: KX-125 problem (Matt Prather)
11. 05:01 PM - Re: Grouping wires for firewall penetration (Rick
Fogerson)
12. 06:18 PM - Re: Grouping wires for firewall penetration (Robert L.
Nuckolls, III)
13. 11:51 PM - Team Grumman (Aucountry@aol.com)
________________________________ Message 1
_____________________________________
Time: 06:48:27 AM PST US
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: AeroElectric-List: Problem with web page?
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
I had a note from a lister citing problems with reading our
web page at:
http://www.aeroelectric.com/Catalog/tools/tools.html
Seems that some of the pictures at the top of the page don't
display. He sent me a capture of the HTML code his browser
sees and indeed, some quotation marks are missing from two
of the HTML tags that call the images in question.
It would be helpful if folks would check this page and
see if any image boxes come up empty. No need to respond
to this message if the page displays okay.
I would like to receive a DIRECT e-mail if anyone
can duplicate our friend's observation.
Thanks!
Bob . . .
--------------------------------------------
( Knowing about a thing is different than )
( understanding it. One can know a lot )
( and still understand nothing. )
( C.F. Kettering )
--------------------------------------------
________________________________ Message 2
_____________________________________
Time: 07:45:27 AM PST US
From: Freddie Freeloader <lists@stevet.net>
Subject: Re: AeroElectric-List: Problem with web page?
--> AeroElectric-List message posted by: Freddie Freeloader
<lists@stevet.net>
Hello Robert,
Tuesday, July 1, 2003, 6:47:17 AM, you wrote:
RLNI> I had a note from a lister citing problems with reading our
RLNI> web page at:
RLNI> http://www.aeroelectric.com/Catalog/tools/tools.html
Yes, the 2 images under the heading "25 Watt, 115 VAC Soldering Iron"
appear as broken links. I'm using Win2K and Mozilla 3.1 browser.
--
Best regards,
Freddie mailto:lists@stevet.net
________________________________ Message 3
_____________________________________
Time: 08:08:38 AM PST US
From: "Bruce Gray" <Bruce@glasair.org>
Subject: RE: AeroElectric-List: Problem with web page?
--> AeroElectric-List message posted by: "Bruce Gray" <Bruce@glasair.org>
All images work for me. (Win2kPro and IE6.0)
Bruce
www.glasair.org
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Freddie Freeloader
Subject: Re: AeroElectric-List: Problem with web page?
--> AeroElectric-List message posted by: Freddie Freeloader
<lists@stevet.net>
Hello Robert,
Tuesday, July 1, 2003, 6:47:17 AM, you wrote:
RLNI> I had a note from a lister citing problems with reading our
RLNI> web page at:
RLNI> http://www.aeroelectric.com/Catalog/tools/tools.html
Yes, the 2 images under the heading "25 Watt, 115 VAC Soldering Iron"
appear as broken links. I'm using Win2K and Mozilla 3.1 browser.
--
Best regards,
Freddie mailto:lists@stevet.net
________________________________ Message 4
_____________________________________
Time: 08:12:50 AM PST US
From: "Bruce Gray" <Bruce@glasair.org>
Subject: RE: AeroElectric-List: Problem with web page?
--> AeroElectric-List message posted by: "Bruce Gray" <Bruce@glasair.org>
Additional information. All was fine with my copy of Mozilla 1.4
browser.
Bruce
www.glasair.org
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Freddie Freeloader
Subject: Re: AeroElectric-List: Problem with web page?
--> AeroElectric-List message posted by: Freddie Freeloader
<lists@stevet.net>
Hello Robert,
Tuesday, July 1, 2003, 6:47:17 AM, you wrote:
RLNI> I had a note from a lister citing problems with reading our
RLNI> web page at:
RLNI> http://www.aeroelectric.com/Catalog/tools/tools.html
Yes, the 2 images under the heading "25 Watt, 115 VAC Soldering Iron"
appear as broken links. I'm using Win2K and Mozilla 3.1 browser.
--
Best regards,
Freddie mailto:lists@stevet.net
________________________________ Message 5
_____________________________________
Time: 08:19:23 AM PST US
Subject: AeroElectric-List: KX-125 problem
From: Bruce Green <mailindex@juno.com>
--> AeroElectric-List message posted by: Bruce Green <mailindex@juno.com>
I have a KX-125 and it had worked fine and then suddenly, it was
inoperative. Sent it out for repairs and they replaced a diode in the
power supply and two transistors in the transmitter for $350. Put it
back in and all was well for about an hour but now it seems to have
suffered the same fate again. I sent it back to the avionics shop and
have not heard what they think yet. Of course I am wondering if there
is something about the plane that created this problem with the radio,
such as a voltage spike. The transponder and intercom run off of the
same circuit and have not failed. I was going to connect a voltmeter and
fly around for a while and see what it does.
Could a bad regulator cause this problem??
Bruce Green
Eagle N110GM
The best thing to hit the internet in years - Juno SpeedBand!
Surf the web up to FIVE TIMES FASTER!
________________________________ Message 6
_____________________________________
Time: 09:23:34 AM PST US
From: "Bob Lee" <bob@flyboybob.com>
Subject: AeroElectric-List: Grounding questions
--> AeroElectric-List message posted by: "Bob Lee" <bob@flyboybob.com>
Bob K,
Unfortunately, I already completed wiring my instrument panel before I found
your wonderful book "The AeroElectric Connection". I just read the chapter
on grounding and am concerned that I might have a problem with ground loops.
I've got a couple of questions that require some background to make sense.
I used a sheet of .060" 7075 aluminum to build the instrument panel. I have
full IFR instruments on the left, radio stack in the center, and engine
instruments on the right in the standard locations. I used the panel as a
ground for everything mounted there (G3) and then ran a number 2 wire to the
battery minus terminal. The firewall is .015 stainless (G2) that is
connected to the battery minus terminal with a number 2 wire. Number 2 was
selected for these two grounds because the two battery bus connections to
the main bus are through 35 amp breakers each. Number 2 will flow 100 amps
so it gives me a margin over the 70 amps maximum available
The crankcase has a 1 foot long 00 wire run to the battery minus terminal.
The two batteries are in a common battery box and their negative terminals
are bolted together with a 1/4" bolt. The alternators are PM units with the
regulators mounted on the firewall. The firewall and instrument panel are
electrically isolated structurally due to composite airframe.
From reading The AeroElectric Connection, it's obvious that I need to update
my wiring diagram with appropriate ground locations for each component.
Before I make the changes I want to make sure I have a good understanding of
the grounding requirements.
With that said, here are my 3 questions:
1. Will the firewall and instrument panel serve as acceptable G2 and G3
ground busses? (I don't want to rewire all the grounds if it is not
necessary)
2. To prevent ground loops should the number 2 wire connections to the
battery minus terminal from the instrument panel and firewall be replaced
with larger wire (if yes what size do you recommend)?
3. I have fuel transfer pumps nav lights and strobes in the wings, should
they be grounded to the firewall to provide the return path to the voltage
regulators?
If you're a visual type, you can see my wiring diagram at:
http://flyboybob.com/kr2/wd0001.htm. It's a seven sheet drawing that comes
up on sheet 1 power distribution. Use the pull down at the bottom of the
page to select sheet 7, Grounding.
Regards,
Bob Lee
______________________________
N52BL KR2 Suwanee, GA 30024
91% done only 51% to go!
Phone/Fax: 770/844-7501
mailto:bob@flyboybob.com
http://flyboybob.com
________________________________ Message 7
_____________________________________
Time: 12:22:25 PM PST US
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: Re: AeroElectric-List: KX-125 problem
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
At 10:33 AM 7/1/2003 -0400, you wrote:
>--> AeroElectric-List message posted by: Bruce Green <mailindex@juno.com>
>
>I have a KX-125 and it had worked fine and then suddenly, it was
>inoperative. Sent it out for repairs and they replaced a diode in the
>power supply and two transistors in the transmitter for $350. Put it
>back in and all was well for about an hour but now it seems to have
>suffered the same fate again. I sent it back to the avionics shop and
>have not heard what they think yet. Of course I am wondering if there
>is something about the plane that created this problem with the radio,
>such as a voltage spike. The transponder and intercom run off of the
>same circuit and have not failed. I was going to connect a voltmeter and
>fly around for a while and see what it does.
>
>Could a bad regulator cause this problem??
Sure. Do you have ov protection? Do you have a voltmeter in the
airplane?
Bob . . .
________________________________ Message 8
_____________________________________
Time: 02:27:28 PM PST US
Subject: Re: AeroElectric-List: KX-125 problem
From: Bruce Green <mailindex@juno.com>
--> AeroElectric-List message posted by: Bruce Green <mailindex@juno.com>
On Tue, 01 Jul 2003 14:21:12 -0500 "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net> writes:
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
> <bob.nuckolls@cox.net>
>
> At 10:33 AM 7/1/2003 -0400, you wrote:
> >--> AeroElectric-List message posted by: Bruce Green
> <mailindex@juno.com>
> >
> >I have a KX-125 and it had worked fine and then suddenly, it was
> >inoperative. Sent it out for repairs and they replaced a diode in
> the
> >power supply and two transistors in the transmitter for $350. Put
> it
> >back in and all was well for about an hour but now it seems to have
> >suffered the same fate again. I sent it back to the avionics shop
> and
> >have not heard what they think yet. Of course I am wondering if
> there
> >is something about the plane that created this problem with the
> radio,
> >such as a voltage spike. The transponder and intercom run off of
> the
> >same circuit and have not failed. I was going to connect a
> voltmeter and
> >fly around for a while and see what it does.
> >
> >Could a bad regulator cause this problem??
>
> Sure. Do you have ov protection? Do you have a voltmeter in the
> airplane?
>
> Bob . . .
>
>
Bob, I do have over voltage protection, but I have never verified that it
is working properly. I do not have a voltmeter, all that I have is an
ammeter like in a car, with a 60-0-60 scale. It is what came with the
plane and at some point, I plan to replace it with a voltmeter. In my
last plane, I bought a davtron unit from B&C that mounted right at the
end of the buss bar and I was very happy with that. The only electric
devices in the airplane are the KX-125, a KT-76 transponder and a PS
Engineering intercom and so far the transponder and intercom have not
been affected. I plan to go flying with my handheld and connect my
multimeter to the bussbar and see what the output is and if there are any
aberations. When I put the battery in, I adjusted the voltmeter to I
believe, 13.8 as the battery manufacture recomended. Should I be looking
for high voltage excursions or just a generally high voltage??
Thanks for your help,
Bruce Green
Eagle N110GM
The best thing to hit the internet in years - Juno SpeedBand!
Surf the web up to FIVE TIMES FASTER!
________________________________ Message 9
_____________________________________
Time: 04:00:46 PM PST US
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: Re: AeroElectric-List: KX-125 problem
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
>
>
>Bob, I do have over voltage protection, but I have never verified that it
>is working properly.
It's a good thing to do. I describe both bench and in-place
test procedures in
http://www.aeroelectric.com/articles/crowbar.pdf
> I do not have a voltmeter, all that I have is an
>ammeter like in a car, with a 60-0-60 scale. It is what came with the
>plane and at some point, I plan to replace it with a voltmeter. In my
>last plane, I bought a davtron unit from B&C that mounted right at the
>end of the buss bar and I was very happy with that.
The voltmeter is a good thing to have . . . better I think
than the battery ammeter . . . but either instrument is just
a troubleshooting assist.
> The only electric
>devices in the airplane are the KX-125, a KT-76 transponder and a PS
>Engineering intercom and so far the transponder and intercom have not
>been affected. I plan to go flying with my handheld and connect my
>multimeter to the bussbar and see what the output is and if there are any
>aberations. When I put the battery in, I adjusted the voltmeter to I
>believe, 13.8 as the battery manufacture recomended. Should I be looking
>for high voltage excursions or just a generally high voltage??
Most automotive and aircraft regulators are set at 14.2 volts
for better recharge rates . . and while slightly elevated
with respect to optimum room temperature floating recharge, it's
not particularly injurious to the battery.
>Thanks for your help,
Put your voltmeter on the bus and fire up the airplane leaving
the radios off. See how stable the voltage is with
variable loading. Run up to 1800+ rpm and switch everything
but radios on. Bus voltage shouldn't wiggle by more than
0.5 volt or so.
Your story seems to favor an ov event. I'd sure check out
the ov protection to be sure.
Bob . . .
________________________________ Message 10
____________________________________
Time: 04:08:22 PM PST US
Subject: Re: AeroElectric-List: KX-125 problem
From: "Matt Prather" <mprather@spro.net>
--> AeroElectric-List message posted by: "Matt Prather" <mprather@spro.net>
Probably a long shot, but I wonder whether the KX-125 is susceptible
to damage from a shorted antenna. King seems like a good brand, and
so probably wouldn't sell a radio with this kind of problem, but its
something else to check.
Another point is that some devices may be more likely to be damaged
by a bus voltage problem. The KX-125 may have the least overvoltage
protect/robust design.
When you say that you adjusted the voltmeter to read 13.8, I assume
you mean that you were adjusting the voltage regulator so that the
voltmeter read 13.8?
Good luck, and let everyone know what you find.
Regards,
Matt-
N34RD
> --> AeroElectric-List message posted by: Bruce Green
> <mailindex@juno.com>
>
>
> On Tue, 01 Jul 2003 14:21:12 -0500 "Robert L. Nuckolls, III"
> <bob.nuckolls@cox.net> writes:
>> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
>> <bob.nuckolls@cox.net>
>>
>> At 10:33 AM 7/1/2003 -0400, you wrote:
>> >--> AeroElectric-List message posted by: Bruce Green
>> <mailindex@juno.com>
>> >
>> >I have a KX-125 and it had worked fine and then suddenly, it was
>> inoperative. Sent it out for repairs and they replaced a diode in
>> the
>> >power supply and two transistors in the transmitter for $350. Put
>> it
>> >back in and all was well for about an hour but now it seems to have
>> suffered the same fate again. I sent it back to the avionics shop
>> and
>> >have not heard what they think yet. Of course I am wondering if
>> there
>> >is something about the plane that created this problem with the
>> radio,
>> >such as a voltage spike. The transponder and intercom run off of
>> the
>> >same circuit and have not failed. I was going to connect a
>> voltmeter and
>> >fly around for a while and see what it does.
>> >
>> >Could a bad regulator cause this problem??
>>
>> Sure. Do you have ov protection? Do you have a voltmeter in the
>> airplane?
>>
>> Bob . . .
>>
>>
>
> Bob, I do have over voltage protection, but I have never verified that
> it is working properly. I do not have a voltmeter, all that I have is
> an ammeter like in a car, with a 60-0-60 scale. It is what came with
> the plane and at some point, I plan to replace it with a voltmeter. In
> my last plane, I bought a davtron unit from B&C that mounted right at
> the end of the buss bar and I was very happy with that. The only
> electric devices in the airplane are the KX-125, a KT-76 transponder and
> a PS Engineering intercom and so far the transponder and intercom have
> not been affected. I plan to go flying with my handheld and connect my
> multimeter to the bussbar and see what the output is and if there are
> any aberations. When I put the battery in, I adjusted the voltmeter to
> I believe, 13.8 as the battery manufacture recomended. Should I be
> looking for high voltage excursions or just a generally high voltage??
>
> Thanks for your help,
>
> Bruce Green
> Eagle N110GM
>
________________________________ Message 11
____________________________________
Time: 05:01:18 PM PST US
From: "Rick Fogerson" <rickf@cableone.net>
Subject: Re: AeroElectric-List: Grouping wires for firewall penetration
--> AeroElectric-List message posted by: "Rick Fogerson"
<rickf@cableone.net>
Hi Bob,
1) Dual batteries, buses, and contactors in the rear.
2) A 2AWG wire connects the two bat cons to the starter con.
3) A 2AWG wire connects the two battery negative terminals to the inst.
panel ground bus.
4) An 8AWG wire connects 40amp alternator B lead to 40amp ANL and then to
starter con.
Rick Fogerson
----- Original Message -----
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: Re: AeroElectric-List: Grouping wires for firewall penetration
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
>
> At 03:27 PM 6/30/2003 -0600, you wrote:
> >--> AeroElectric-List message posted by: "Rick Fogerson"
<rickf@cableone.net>
> >
> >Do not archive
> >Hi Bob,
> >I was thinking the starter contactor normally went on the cockpit side of
> >the firewall. I'm getting the idea that maybe it should go on the engine
> >side. If this is correct or does it matter?
>
> People have stuck them everywhere. I prefer to use the starter
> contactor as a junction point for attaching the alternator b-lead
> to the system via ANL current limiter setting right next to the
> starter contactor on the engine side of the firewall. Where
> is your battery mounted?
>
> Bob . . .
>
>
________________________________ Message 12
____________________________________
Time: 06:18:42 PM PST US
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: Re: AeroElectric-List: Grouping wires for firewall penetration
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
At 06:02 PM 7/1/2003 -0600, you wrote:
>--> AeroElectric-List message posted by: "Rick Fogerson"
<rickf@cableone.net>
>
>Hi Bob,
>1) Dual batteries, buses, and contactors in the rear.
>2) A 2AWG wire connects the two bat cons to the starter con.
>3) A 2AWG wire connects the two battery negative terminals to the inst.
>panel ground bus.
>4) An 8AWG wire connects 40amp alternator B lead to 40amp ANL and then to
>starter con.
>Rick Fogerson
Okay. So it's about a wash as to where you put the starter
contactor. If inside, then you have starter and b-leads
coming through the firewall. If outside on firewall, you have
battery feeder to the starter contactor and main-bus feeds
coming through the firewall. Either way it's two fat wires.
So if you have it mounted inside already, I wouldn't move it.
Bob . . .
________________________________ Message 13
____________________________________
Time: 11:51:14 PM PST US
From: Aucountry@aol.com
Subject: AeroElectric-List: Team Grumman
--> AeroElectric-List message posted by: Aucountry@aol.com
Matt, how and when can I start enlisting members into TeamGrumman? The
rules you post make a lot more sense than the GG rules.
Gary
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|