Today's Message Index:
----------------------
0. 09:51 AM - Fund Raiser Behind By 28% - Please Contribute Today! (Matt Dralle)
1. 09:13 AM - Re: Re: Audio Isolation Amplifier Boards (Robert L. Nuckolls, III)
2. 09:15 AM - Re: Audio Isolation Amplifier Boards (Robert L. Nuckolls, III)
3. 11:33 AM - Fund Raiser (Charlie England)
4. 12:02 PM - Re: Fund Raiser (Bill)
5. 01:46 PM - Re: Fund Raiser (bobsv35b@aol.com)
6. 06:06 PM - Wiring Harness Installed (Art Zemon)
7. 06:50 PM - Re: Wiring Harness Installed (Robert L. Nuckolls, III)
8. 07:39 PM - Re: Wiring Harness Installed (Art Zemon)
9. 07:50 PM - Re: Re: Problems Soldering DB-25 Connectors (Art Zemon)
Message 0
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Subject: | Fund Raiser Behind By 28% - Please Contribute Today! |
Dear Listers,
The percentage of members making a Contribution to support the Lists this year
is currently behind last year by at this time by roughly 28%. Please take this
opportunity to show your support for the Matronics Lists and Forums!
Please remember that it is *solely* your direct Contributions that keep these Lists
and Forums up and running and most importantly - AD FREE! If the members
don't want to support the Lists directly, then I might have to add advertisements
to offset the costs of running the Lists. But I don't want to have to do
that. I really like the non-commercial atmosphere here and I think that a lot
of the members appreciate that too.
Please take a moment to make a Contribution today in support of the continued ad-free
operation of all these Lists:
http://www.matronics.com/contribution
Or, drop a personal check in the mail to:
Matt Dralle / Matronics
581 Jeannie Way
Livermore CA 94550
USA
I want to send out a word of appreciation to all of the members that have already
made their generous Contribution to support the Lists!
Thank you!
Matt Dralle
Email List and Forums Administrator
Message 1
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Subject: | Re: Audio Isolation Amplifier Boards |
At 09:40 AM 11/27/2016, you wrote:
>
>Bob,
>
>Did you mean bare (not etched) circuit boards?
>
>If so, a trip to you local PCB fab house will get you a truckload of
>boards in various thicknesses and single-double side configurations.
>
>Eric
No, our 9009-300-2A etched circuit board is
a component of the DIY audio isolation
amplifier project described in . . .
http://tinyurl.com/ngoo6hc
Emacs!
Perhaps the better term is 'unpopulated'. It looks
like this when you're done.
Emacs!
Bob . . .
Message 2
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Subject: | Re: Audio Isolation Amplifier Boards |
At 08:18 PM 11/26/2016, you wrote:
>I was wondering the same thing so I had a look at the .pdf. As far
>as I can tell it's a budget way of tying in several radios to your
>intercom without spending thousands on an audio panel.
Correct. Notice too on the pictures that
there are gain setting resistors installed
in a socket. For audio sources with no
adjustable output, you can select the
resistor that levels that source with
the rest of your sources.
Bob . . .
Message 3
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I just want to encourage everyone to chip in, to keep Matt's lists
alive. I've been around these lists for a very long time, and there's no
better run aviation forum out there. The number of times I've gotten
help from these lists is uncountable.
I've been guilty over the years of not contributing, but as I see so
many other clunky, over-moderated, advertising loaded sites, I'm much
more motivated to help Matt keep fighting the good fight.
I hope y'all will agree, and put your wallets where your mouths are. :-)
Matt makes it easy to do; just pick your favorite method & amount.
Charlie
Message 4
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I agree whole-heartedly Charlie.
Do not archive
Bill
Castro Valley
On Mon, Nov 28, 2016 at 11:31 AM, Charlie England <ceengland7@gmail.com>
wrote:
> ceengland7@gmail.com>
>
> I just want to encourage everyone to chip in, to keep Matt's lists alive.
> I've been around these lists for a very long time, and there's no better
> run aviation forum out there. The number of times I've gotten help from
> these lists is uncountable.
>
> I've been guilty over the years of not contributing, but as I see so many
> other clunky, over-moderated, advertising loaded sites, I'm much more
> motivated to help Matt keep fighting the good fight.
>
> I hope y'all will agree, and put your wallets where your mouths are. :-)
> Matt makes it easy to do; just pick your favorite method & amount.
>
> Charlie
>
>
Message 5
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Good Afternoon Bill,
Totally agree that Matt's lists are well worth supporting.
However I do believe I contributed when first asked for this year yet I am now
getting requests from someone whose name I do not recognize asking for additional
contributions.
Any idea what is happening?
Do I now show as not having contributed?
Happy Skies,
Old Bob
AKA
Bob Siegfried
Downers Grove, IL
-----Original Message-----
From: Bill <wtrooper@gmail.com>
Sent: Mon, Nov 28, 2016 2:08 pm
Subject: Re: AeroElectric-List: Fund Raiser
I agree whole-heartedly Charlie.
Do not archive
Bill
Castro Valley
On Mon, Nov 28, 2016 at 11:31 AM, Charlie England <ceengland7@gmail.com> wrote:
I just want to encourage everyone to chip in, to keep Matt's lists alive. I've
been around these lists for a very long time, and there's no better run aviation
forum out there. The number of times I've gotten help from these lists is uncountable.
I've been guilty over the years of not contributing, but as I see so many other
clunky, over-moderated, advertising loaded sites, I'm much more motivated to
help Matt keep fighting the good fight.
I hope y'all will agree, and put your wallets where your mouths are. :-) Matt makes
it easy to do; just pick your favorite method & amount.
Charlie
===================================
br>fts!)
r>>/www.aeroelectric.com" rel="noreferrer" target="_blank">www.aeroelectric.com
w.buildersbooks.com" rel="noreferrer" target="_blank">www.buildersbooks.com
p.com" rel="noreferrer" target="_blank">www.homebuilthelp.com
e.com" rel="noreferrer" target="_blank">www.mypilotstore.com
" rel="noreferrer" target="_blank">www.mrrace.com
rel="noreferrer" target="_blank">http://www.matronics.com/contribution
-Matt Dralle, List Admin.
Message 6
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Subject: | Wiring Harness Installed |
Folks,
I've said it before but I need to say it again: *Thank you* for all of your
advice and mentoring and generosity. Over the Thanksgiving weekend, I
installed the first large piece of the wiring harness in my Bede BD-4C.
There are lots of pictures (and probably way too many words) on my
blog at Wiring
Harness Installed
<https://cheerfulcurmudgeon.com/2016/11/28/wiring-harness-installed/>.
Cheers,
-- Art Z.
--
https://CheerfulCurmudgeon.com/
*"If I am not for myself, who is for me? And if I am only for myself, what
am I? And if not now, when?" Hillel*
Message 7
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Subject: | Re: Wiring Harness Installed |
At 08:04 PM 11/28/2016, you wrote:
>Folks,
>
>I've said it before but I need to say it again:
>Thank you=C2 for all of your advice and mentoring
>and generosity. Over the Thanksgiving weekend, I
>installed the first large piece of the wiring
>harness in my Bede BD-4C. There are lots of
>pictures (and probably way too many words) on my
>blog at
><https://cheerfulcurmudgeon.com/2016/11/28/wiring-harness-installed/>Wiring
>Harness Installed.
Thank you for sharing this sir. One thought popped
up while reviewing the post . . . how LONG and what
SIZE are the pigtails on the paralleled d-sub pins?
You want the RESISTANCE of the pigtails to be significantly
larger than the resistance of each pin which is on
the order of 3 to 5 milliohms. I think we talked about
this some weeks back. As a rule of thumb, I try to put
12" of 22AWG wire in the 'ballasting' resitance
of each pin. This can be 6" pigtails on either side
of a connector interface . . . or 12" on one side
when the mating connector's wiring is not accessible
to you (like an etched circuit board connector).
12" of 22AWG is 16 milliohms give or take. When ever
I suggest this methodology for the misapplication of
d-subs, I strive to make this pigtail length and size
clear and perhaps even explain why. So while your
photos and narrative are excellent, I'll suggest you
add a notation that those 22AWG pigtails should be
on the order of 12" TOTAL.
Other than this niggling little detail, I'm impresses
with your work and willingness to pass along what
you've learned to others.
Bob . . .
Message 8
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Subject: | Re: Wiring Harness Installed |
Bob,
The pigtails are 12" total, 6" on each side of the connector, just as you
specified. I will definitely update my blog post because this is an
important point. IIRC, you had a write up about this on your website
somewhere. Please point me at it so that I can include the pointer in my
blog post.
Cheers,
-- Art Z.
On Mon, Nov 28, 2016 at 8:49 PM, Robert L. Nuckolls, III <
nuckolls.bob@aeroelectric.com> wrote:
> At 08:04 PM 11/28/2016, you wrote:
>
> Folks,
>
> I've said it before but I need to say it again: *Thank you*=C3=82 for all
of
> your advice and mentoring and generosity. Over the Thanksgiving weekend,
I
> installed the first large piece of the wiring harness in my Bede BD-4C.
> There are lots of pictures (and probably way too many words) on my blog a
t Wiring
> Harness Installed
> <https://cheerfulcurmudgeon.com/2016/11/28/wiring-harness-installed/>.
>
>
> Thank you for sharing this sir. One thought popped
> up while reviewing the post . . . how LONG and what
> SIZE are the pigtails on the paralleled d-sub pins?
>
> You want the RESISTANCE of the pigtails to be significantly
> larger than the resistance of each pin which is on
> the order of 3 to 5 milliohms. I think we talked about
> this some weeks back. As a rule of thumb, I try to put
> 12" of 22AWG wire in the 'ballasting' resitance
> of each pin. This can be 6" pigtails on either side
> of a connector interface . . . or 12" on one side
> when the mating connector's wiring is not accessible
> to you (like an etched circuit board connector).
>
> 12" of 22AWG is 16 milliohms give or take. When ever
> I suggest this methodology for the misapplication of
> d-subs, I strive to make this pigtail length and size
> clear and perhaps even explain why. So while your
> photos and narrative are excellent, I'll suggest you
> add a notation that those 22AWG pigtails should be
> on the order of 12" TOTAL.
>
> Other than this niggling little detail, I'm impresses
> with your work and willingness to pass along what
> you've learned to others.
>
>
> Bob . . .
>
--
https://CheerfulCurmudgeon.com/
*"If I am not for myself, who is for me? And if I am only for myself, what
am I? And if not now, when?" Hillel*
Message 9
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Subject: | Re: Problems Soldering DB-25 Connectors |
Bob,
I found your explanation about the ballasting 22 AWG pigtails. It was in an
email to me, not on your website. I will use this to update my blog post.
-- Art Z.
On Thu, Sep 22, 2016 at 9:01 AM, Robert L. Nuckolls, III <
nuckolls.bob@aeroelectric.com> wrote:
> At 08:22 PM 9/21/2016, you wrote:
>
>
> Be careful about dry joints, the solder should be bright and shiny all
> around
> the joint.
>
>
> . . . which is easy to achieve with 63/37 solder featuring
> quality flux.
>
> If the wire is carrying just signal, clipping a strand or two should
> be fine . . .
>
>
> I've attached 18 AWG wires to solder-cups by trimming
> back excess strands. This was a system with long runs
> of wire where voltage drop was an issue. There are
> companies that make special adapters to put too-large
> wires into 20AWG solder-cups but trimming the strands
> is more compact and works good too.
>
> (with adequate strain relief).
>
>
> The backshell is were wire-support takes place.
> Heat shrink is more of a hedge against pin-to-pin
> shorts by conductive contaminants . . . a thing
> that just doesn't happen in a clean work environment.
>
>
> Power carrying wire demand more careful consideration
> about potential resistive heating and voltage drop.
>
>
> Sort of . . . but pin-to-socket interface within
> the connector is the driving concern about path
> resistance. 20AWG wire is 10 milliohms per FOOT,
> 22AWG is 16 mOhms/Ft. A single pin-to-socket
> interface on a d-sub can present 3 millioms of
> resistance over a millimeter. Variability in
> resistance between pin-to-socket interface within
> a connector gives rise to the prohibition for
> paralleling pins to increase current handling
> of any one path.
>
> I designed and qualified a paralleled d-sub pin
> process at Beech that was used in both targets
> and production aircraft. This involved EXTENDING
> each pin in a paralleled array with say 12" of
> 22AWG wire before the pin-paths were joined in
> parallel. This ADDS 16 milliohms resistance to
> each 1-3 milliohm pin-to-socket variability.
> This 'ballasting' resistance forces the sharing
> of current across an array of paralleled pins.
>
> The short answer is that concerns for heating
> due to current flow reside in the pins . . .
> not the wires.
>
> Bob . . .
>
--
https://CheerfulCurmudgeon.com/
*"If I am not for myself, who is for me? And if I am only for myself, what
am I? And if not now, when?" Hillel*
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