Today's Message Index:
----------------------
1. 06:31 AM - Re: Amp 59250 t-head tool (Robert L. Nuckolls, III)
2. 06:52 AM - Eclispe crimping tool? (earl_schroeder@juno.com)
3. 07:19 AM - Re: Amp 59250 t-head tool (BobsV35B@aol.com)
4. 07:34 AM - Re: Eclispe crimping tool? (Robert L. Nuckolls, III)
5. 07:35 AM - Re: Alternator whine in audio (Robert L. Nuckolls, III)
6. 07:43 AM - Re: swapping two radios using 3P/DT switch? (Robert L. Nuckolls, III)
7. 09:07 AM - swapping two radios using 3P/DT switch? (BUCSDDS@aol.com)
8. 02:08 PM - Re: Alternator whine in audio (Robert Feldtman)
9. 02:46 PM - Yahoo! Auto Response (jpiamber@yahoo.com)
10. 03:54 PM - Re: Firewall Placement Of Electrical Components (Robert L. Nuckolls, III)
11. 04:42 PM - Re: 20 Amp Solid State Relay usage (Robert L. Nuckolls, III)
Message 1
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Subject: | Re: Amp 59250 t-head tool |
At 10:25 AM 12/20/2007 -0500, you wrote:
>Good Morning 'Lectric Bob,
>
>You mentioned once that you had sent your T head crimper in for a rebuild.
>Do you know if such a service is still available?
>
>If so, where and how much ? <G>
I don't know. That would have been about 1965! I got
the address of the rebuild shop from a guy in a toolcrib
at the Cessna East Pawnee plant who was responsible
for tool screening and maintenance. After having bought
a "worn out" tool from Cessna salvage for $25, it was
a long step to add another $50 or so to that to make it
a zero time tool!
You can search the Tyco-Amp for "refurbish" or "rebuild"
services.
Bob . . .
Message 2
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Subject: | Eclispe crimping tool? |
Hi Bob [or other contributors],
I purchased the crimping tool referenced in this URL:
http://www.mpja.com/prodinfo.asp?number=15534+TL
However, it came with no instructions or illustrations as to its use.
I suppose I could use trial and error but prefer some helpful hints.
Thanks, Earl
PS searching the archives, produced none that I could find.
_____________________________________________________________
Online Stock Trading - Straightforward pricing. Powerful tools. Click here!
http://thirdpartyoffers.juno.com/TGL2121/fc/Ioyw6i3mJ8X0xeveOtvWEDbDHQb3OPK9ixAAfti9QiZFE9N30DXS3n/
Message 3
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Subject: | Re: Amp 59250 t-head tool |
Thanks Bob, I'll get on it! (sometime that is.)
Happy Skies,
Old Bob
In a message dated 12/21/2007 8:33:35 A.M. Central Standard Time,
nuckolls.bob@cox.net writes:
I don't know. That would have been about 1965! I got
the address of the rebuild shop from a guy in a toolcrib
at the Cessna East Pawnee plant who was responsible
for tool screening and maintenance. After having bought
a "worn out" tool from Cessna salvage for $25, it was
a long step to add another $50 or so to that to make it
a zero time tool!
You can search the Tyco-Amp for "refurbish" or "rebuild"
services.
Bob . . .
**************************************See AOL's top rated recipes
(http://food.aol.com/top-rated-recipes?NCID=aoltop00030000000004)
Message 4
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Subject: | Re: Eclispe crimping tool? |
At 02:50 PM 12/21/2007 +0000, you wrote:
><earl_schroeder@juno.com>
>
>Hi Bob [or other contributors],
>I purchased the crimping tool referenced in this URL:
>http://www.mpja.com/prodinfo.asp?number=15534+TL
>
>However, it came with no instructions or illustrations as to its use.
>
>I suppose I could use trial and error but prefer some helpful hints.
>
>Thanks, Earl
>
>PS searching the archives, produced none that I could find.
It's pretty straight-forward. You need to strip the wire
just enough that the strands bottom out in the back of
the pin just before the insulation touches the pin. Hold
the wire/pin up vertically and drop the tool over it until
the pin is fully seated in the tool. The pin will be flush
to just underflush with the working face of the tool. Put
the mash on it an you're done.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
Message 5
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Subject: | Re: Alternator whine in audio |
At 04:20 PM 12/20/2007 +0000, you wrote:
>Hello All,<?xml:namespace prefix = o ns =
>"urn:schemas-microsoft-com:office:office" />
>
> I have a PlanePower alternator and have noticed a whine noise in the
> David Clark headset audio. It is really noisy if the headset volume is
> high; however, if I turn the headset volume down low and turn the comm
> radio volume up to compensate, the whine is barely detectable. Can anyone
> explain this and/or provide possible solutions?
Yes. The alternator is the noisiest device in the
airplane and there is no practical way to 'filter'
its worst noise component - AC 'ripple' voltage
left over after the 3-phase AC output of the stator
windings is rectified into DC.
The simple-ideas that support this assertion are
illustrated in an excerpted figure from the chapter
on noise in the 'Connection which you can see
here:
http://www.aeroelectric.com/Pictures/Misc/Figure_16p3.pdf
A rectified 3-phase AC voltage has a predictable
10% pk-pk ripple. I.e., your 14V alternator has
about 1.4 volts pk-pk AC signal at an audio rate
(you can hear it) riding on top of the DC power
output. Worse yet, the ENERGY in this 'noise'
is HUGE . . . let's say .5v RMS X alternator
output of up to say 60A makes this a 30 WATT
potential noise source.
The notion of adding a practical filter for this
condition is polluted by the knowledge that
many of the more useful filters for radio noise
are fairly easy pills to swallow (.5 lb, 10 square
inches footprint and perhaps 30 cubic inches
in volume). However, these are designed to work
at Megahertz frequencies and energy levels
perhaps 1 millionth as strong.
A filter capable of cleaning up the output
of an alternator is going to be more weight,
volume and loss of power than you're going
to want to put in your airplane.
This is why the graybeards in this technology
have provided guidance to designers in the form
of Mil-Std-704 and similar tomes that say, "Son,
that's one nasty noise generator out there on
the engine with no practical way to silence it.
Suggest you learn to live with it."
Indeed, DC power generation per Mil-Std-704
tells us to expect 3 volts pk-pk on 28v systems
as described in
http://www.aeroelectric.com/Pictures/Curves/MSTD704_28V_Noise.jpg
over the range of 1000 to 5000 Hz (you can HEAR
it) and tapering in intensity on either side.
Cut that value in half for a 14v system. Here's
a noise trace taken from my automobile's bus:
http://www.aeroelectric.com/Pictures/Curves/Safari_Bus_Noise_1.gif
>I called PlanePower to inquire about filter and they informed me that
>their product has internal noise filtering and that I must have an audio
>ground problem.
But they didn't tell you everything. The only kind
of filter that can be physically installed in their
alternator goes to conducted RADIO FREQUENCY noise
from 150 KHz to 30 MHz in the form of a reasonably
sized capacitor. This filter cannot speak to the
AUDIO FREQUENCY noise described in the Mil-Std-704
excerpt cited above.
Their hypothesis about audio ground noise is a
strong one. The vast majority of audio system noise
problems I've encountered in the past had root
cause in poor ground architecture. This is why we
spend so much time exploring the potential for
grounding problems in chapter 16 and crafted the
ground architecture drawings in Figure Z-15.
> When the alternator is switched off-line, the audio is crystal clear. If
> there was an
> audio grounding issue I would expect to hear ignition noise too, but
> that's not
> the case.
A faulty supposition. The propagation modes for
these two antagonists are entirely different from
each other. The presence of one does not automatically
include or exclude the presence of both.
>Can additional filtering be installed external to the alternator?
No.
> Suggestions please.
Suggest you first make sure that your headset
and microphone jacks DO NOT ground locally to
the airframe where they are mounted. This common
installation error probably accounts for 1/2 of
all the light aircraft alternator noise problems.
Understand too that you MIGHT have a propagation
mode that is difficult to find and/or fix. With
the advent of high quality, noise cancelling
headsets noises that used to be well below the
nuisance threshold for signal to noise are now
deemed undesirable. I'm not suggesting that your
problem is not fixable . . . just that the cost
in $time$ to fix it may not be very rewarding.
Is the noise you're hearing on the ground perceptible
and objectionable in flight? I've had MANY situations
where folks have chased over an airplane looking
for root cause and fix for noises that nobody
can hear while in flight.
If the mic/headset jacks ARE properly grounded
back at the intercom, then try running the noise
isolation traps described in Chapter 16. The noise
MIGHT be coming in through the +14v power leads
where its practical to add a filter like:
http://www.aeroelectric.com/articles/filter/RS_Noise_Filters.pdf
http://www.aeroelectric.com/articles/filter/filter.pdf
Unfortunately, all the components featured in
these two pieces are no longer offered by Radio
Shack since they got out of the automotive audio
products business. However, other companies
are very much IN that business. If your studies
determine that the noise IS coming in through the
+14v supply, perhaps a device like . . .
http://tinyurl.com/ynn7at
would do the job. There's no automatic recipe
for success here because the variables that set
levels of perception for the noise have a huge
range of cause/effect. Noise problems of this
nature are always plagued with a certain amount
of cut and try.
I've copied my friend Steven Klodd at Plane-Power
on this note. Steve, should you find it useful,
feel free to copy any or all of this stuff and
assemble it into a document for sharing with your
customers. A poor understanding of these simple-
ideas has cause our brothers to spend a lot of
$time$ chasing the elusive double-ugly, yellow-
beaked noise snipe!
Bob . . .
Message 6
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Subject: | Re: swapping two radios using 3P/DT switch? |
At 12:09 PM 12/20/2007 -0800, you wrote:
>Bob and/or other electronics gurus--
>
>I'm using revision 11 and looking at chapter 11 (switches) and also the
>FAQ's...I have attached an excerpt from the FAQ's that I think applies to
>my question as well...it's a gentleman inquiring about using either a
>"3PDT" switch (I think numerically this is a "3-3 switch"?) to change
>between two comm radios.
>
>If I have a panel mount comm radio (with it's own antenna) and a portable
>comm radio (an SP-200 with it's own antenna) and a simple two-place
>intercom system (i.e. PM 3000), I believe I need the above referenced
>three-pole double-throw (3-3) switch to swap between the two radios: a
>pole for the wire going to the headset earphones, a pole for the wire
>coming from the headset microphone, and a pole to swap the PTT line. By
>doing this, I can swap radios without having to go through the intercom
>system which is in-line with your philosophy (which I agree with) of
>minimizing knob-twisting distractions. I don't see any examples of triple
>pole switches in the book and I can't find any in the Spruce catalog, but
>if I'm thinking correctly, do you have a suggested resource for obtaining
>one? Otherwise is there another switching logic I should consider? Once
>again, everyone please feel free to shoot holes in my ideas. Thanks.
>
>Lincoln Keill
>Sacramento, CA
Check out the C&K 7301P3YZQE switch at:
http://tinyurl.com/ypqomr
and
http://www.aeroelectric.com/Pictures/Switches/7301P3YZQE.jpg
Bob . . .
Message 7
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Subject: | swapping two radios using 3P/DT switch? |
Bob or anyone else with the correct answer to my question,
I have an issue with my Headset/PTT/Microphone wiring. I have a Garmin
SL-30, SL-40 and the PMA 4000 by PS Engineering intercom. I hear a squeal when
I
press the PTT switch. If the intercom is turned off the squeal doesn't occur
while pressing the PTT switch. I'm wondering if a 3P/DT switch would be a good
option. If so, what schematic should I use??
Thanks in advance for any help!
Marwin Goff
Des Moines, IA
Marwin Goff
DSM
Varieze O-200
515-360-0778
bucsdds@aol.com
**************************************See AOL's top rated recipes
(http://food.aol.com/top-rated-recipes?NCID=aoltop00030000000004)
Message 8
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Subject: | Re: Alternator whine in audio |
there are noise filters in the amateur radio realm that work reasonably
well..... I am thinking about trying that in my audio ciruit to headphone to
see if I could "tune out" the noise. Any pilots using those? You can see
them advertised in QST, etc.
bobf
Glastar
W5RF
On 12/21/07, Robert L. Nuckolls, III <nuckolls.bob@cox.net> wrote:
>
> nuckolls.bob@cox.net>
>
> At 04:20 PM 12/20/2007 +0000, you wrote:
>
> >Hello All,<?xml:namespace prefix = o ns
> >"urn:schemas-microsoft-com:office:office" />
> >
> > I have a PlanePower alternator and have noticed a whine noise in the
> > David Clark headset audio. It is really noisy if the headset volume is
> > high; however, if I turn the headset volume down low and turn the comm
> > radio volume up to compensate, the whine is barely detectable. Can
> anyone
> > explain this and/or provide possible solutions?
>
> Yes. The alternator is the noisiest device in the
> airplane and there is no practical way to 'filter'
> its worst noise component - AC 'ripple' voltage
> left over after the 3-phase AC output of the stator
> windings is rectified into DC.
>
> The simple-ideas that support this assertion are
> illustrated in an excerpted figure from the chapter
> on noise in the 'Connection which you can see
> here:
>
> http://www.aeroelectric.com/Pictures/Misc/Figure_16p3.pdf
>
>
> A rectified 3-phase AC voltage has a predictable
> 10% pk-pk ripple. I.e., your 14V alternator has
> about 1.4 volts pk-pk AC signal at an audio rate
> (you can hear it) riding on top of the DC power
> output. Worse yet, the ENERGY in this 'noise'
> is HUGE . . . let's say .5v RMS X alternator
> output of up to say 60A makes this a 30 WATT
> potential noise source.
>
> The notion of adding a practical filter for this
> condition is polluted by the knowledge that
> many of the more useful filters for radio noise
> are fairly easy pills to swallow (.5 lb, 10 square
> inches footprint and perhaps 30 cubic inches
> in volume). However, these are designed to work
> at Megahertz frequencies and energy levels
> perhaps 1 millionth as strong.
>
> A filter capable of cleaning up the output
> of an alternator is going to be more weight,
> volume and loss of power than you're going
> to want to put in your airplane.
>
> This is why the graybeards in this technology
> have provided guidance to designers in the form
> of Mil-Std-704 and similar tomes that say, "Son,
> that's one nasty noise generator out there on
> the engine with no practical way to silence it.
> Suggest you learn to live with it."
>
> Indeed, DC power generation per Mil-Std-704
> tells us to expect 3 volts pk-pk on 28v systems
> as described in
>
> http://www.aeroelectric.com/Pictures/Curves/MSTD704_28V_Noise.jpg
>
> over the range of 1000 to 5000 Hz (you can HEAR
> it) and tapering in intensity on either side.
> Cut that value in half for a 14v system. Here's
> a noise trace taken from my automobile's bus:
>
> http://www.aeroelectric.com/Pictures/Curves/Safari_Bus_Noise_1.gif
>
> >I called PlanePower to inquire about filter and they informed me that
> >their product has internal noise filtering and that I must have an audio
> >ground problem.
>
> But they didn't tell you everything. The only kind
> of filter that can be physically installed in their
> alternator goes to conducted RADIO FREQUENCY noise
> from 150 KHz to 30 MHz in the form of a reasonably
> sized capacitor. This filter cannot speak to the
> AUDIO FREQUENCY noise described in the Mil-Std-704
> excerpt cited above.
>
> Their hypothesis about audio ground noise is a
> strong one. The vast majority of audio system noise
> problems I've encountered in the past had root
> cause in poor ground architecture. This is why we
> spend so much time exploring the potential for
> grounding problems in chapter 16 and crafted the
> ground architecture drawings in Figure Z-15.
>
> > When the alternator is switched off-line, the audio is crystal clear.
> If
> > there was an
> > audio grounding issue I would expect to hear ignition noise too, but
> > that's not
> > the case.
>
> A faulty supposition. The propagation modes for
> these two antagonists are entirely different from
> each other. The presence of one does not automatically
> include or exclude the presence of both.
>
> >Can additional filtering be installed external to the alternator?
>
> No.
>
> > Suggestions please.
>
> Suggest you first make sure that your headset
> and microphone jacks DO NOT ground locally to
> the airframe where they are mounted. This common
> installation error probably accounts for 1/2 of
> all the light aircraft alternator noise problems.
>
> Understand too that you MIGHT have a propagation
> mode that is difficult to find and/or fix. With
> the advent of high quality, noise cancelling
> headsets noises that used to be well below the
> nuisance threshold for signal to noise are now
> deemed undesirable. I'm not suggesting that your
> problem is not fixable . . . just that the cost
> in $time$ to fix it may not be very rewarding.
>
> Is the noise you're hearing on the ground perceptible
> and objectionable in flight? I've had MANY situations
> where folks have chased over an airplane looking
> for root cause and fix for noises that nobody
> can hear while in flight.
>
> If the mic/headset jacks ARE properly grounded
> back at the intercom, then try running the noise
> isolation traps described in Chapter 16. The noise
> MIGHT be coming in through the +14v power leads
> where its practical to add a filter like:
>
> http://www.aeroelectric.com/articles/filter/RS_Noise_Filters.pdf
>
> http://www.aeroelectric.com/articles/filter/filter.pdf
>
> Unfortunately, all the components featured in
> these two pieces are no longer offered by Radio
> Shack since they got out of the automotive audio
> products business. However, other companies
> are very much IN that business. If your studies
> determine that the noise IS coming in through the
> +14v supply, perhaps a device like . . .
>
> http://tinyurl.com/ynn7at
>
> would do the job. There's no automatic recipe
> for success here because the variables that set
> levels of perception for the noise have a huge
> range of cause/effect. Noise problems of this
> nature are always plagued with a certain amount
> of cut and try.
>
> I've copied my friend Steven Klodd at Plane-Power
> on this note. Steve, should you find it useful,
> feel free to copy any or all of this stuff and
> assemble it into a document for sharing with your
> customers. A poor understanding of these simple-
> ideas has cause our brothers to spend a lot of
> $time$ chasing the elusive double-ugly, yellow-
> beaked noise snipe!
>
> Bob . . .
>
>
Message 9
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Subject: | Yahoo! Auto Response |
JPI will be closed to observe Christmas
December 22ND and will return on December 27TH.
JPI will be closed to observe the New Year Holiday
December 29TH and will return on January 2ND.
The holiday season offers us a special opportunity to extend our personal thanks
to our friends, and our very best wishes for the future.
And so it is that we now gather together and wish to you a very Merry Christmas
and a Happy New Year. We consider you a good friend and extend our wishes for
good health and good cheer.
It is people like you who make being in business such a pleasure all year long.
Our business is a source of pride to us, and with customers like you, we find
going to work each day a rewarding experience.
To our friends all over the world, JP Instruments
extends to you and your loved ones our best wishes for a
Vrolijke Kersttmis Sarbatori Felicite
Joyeux Noel Tin Hao Nian
Froeliche Weihnachten Felice Natale
Kinga Shinnen Glad Julen
Ichok Yilara Boas Festas
Chrustovjna Wesloych Swiat
Glaedelig Jul Veselele Vanoche
Felice Pascuas Sretan Bozic
Boldog Karacsonyi Unnepeket Merry Christmas
and a Happy New Year!
Message 10
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Subject: | Re: Firewall Placement Of Electrical Components |
At 08:39 AM 12/20/2007 -0800, you wrote:
><david.m.gallagher@ge.com>
>
>I am building a Zenith 601 and using a variation of the Z16 drawing. I am
>currently working on placing my regulator, S704-1 OV relay and
>capacitor. The B&C instructions are pretty clear that this stuff should
>be mounted on the cockpit side of the firewall and away from engine
>heat. In this configuration, the Z16 would have me running a 12GA from
>the capacitor, through the firewall, and out to the up-leg screw on the
>starter relay. I would also have a 12GA going from the down-leg screw of
>the battery relay, through the firewall, and to the main distribution
>bus. My question is two-fold:
>
>1. Is it critical that these electrical parts be on the backside of the
>firewall. I have seen photos of this stuff on the engine side on other
>airplanes.
Everyone likes to "stay cool" but virtually every
product I design these days is required to live
and work in a 55C environment minimum and virtually
all our stuff can be demonstrated to run up to 100C.
Lots of folks have installed the B&C products and
the products of others on the engine side of the
firewall with no complaints. Your risks are low.
>2. If I follow B&C's recommendation on placement, can I run the
>alternator lead from the capacitor straight to the main distribution
>bus? This would only require one 12GA wire firewall penetration from the
>bus to the battery relay.
If it's a cleaner installation to go up front, go ahead
and do it.
Bob . . .
Message 11
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Subject: | 20 Amp Solid State Relay usage |
At 02:34 PM 12/10/2007 -0700, you wrote:
>
>I too am using the AML34 and AML24 switches in my panel. Pacific Coast
>Avionics recommended using the Potter Brumfield VF4-65F11 relays for higher
>loads.
>
>Any thoughts on these relays Bob? Are they reliable enough?
"Reliable enough" isn't quantifiable . . . if you use
them with failure tolerant design in mind, then any
component demonstrating a service life commensurate with
your $time$ to acquire/install/maintain will have no
serious effect on system reliability, only a
cost of ownership consideration.
The plastic automotive power relays are in widespread
usage throughout the industry. Chances are that
they're entirely suited to your task of crafting
the failure tolerant system.
Bob . . .
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