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Old May 4th 06, 07:14 PM posted to rec.aviation.owning
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Default Avionics Help/Recommendations Neede

This is how I have done the 182, the 172 before that, and the 170 before
that.

Radios will change. Audio panels will change. Intercoms will change. The
182 started out life with a 90 channel MK-12 and a Lear ADF. By my count,
it has gone through 43 separate and individual avionics changes in its 50
year history. That's about one every year or so.

None of the radios in the 182 are directly connected to the audio panel, and
I have dual King 170Bs, an amateur (ham) 2 meter rig, and an XM satellite
music radio all running through the audio panel.

Here's the deal, and terminal strip is the mantra. Call up www.mouser.com
and search for "Cinch series 140" (without the quotation marks). It will
tell you that to see the device click on "page 1137". If you are on dialup,
this page will take about a minute to load.

Every radio has its own personal 8-pin terminal strip. Power, ground,
speaker, phones, mic audio, mic key, lights, and a spare. But it doesn't
stop there. Go back to the Mouser search page and search for "Molex .062" "
(without the quotation marks but with the "inch mark after .062). This is a
series of small nylon connectors that go for a couple of bucks each. Been
using both terminal strips and nylon connectors for forty years without a
single failure.

Now, the radio comes with a horrendously expensive (and generally made out
of unobtanium) connector. That connector gets wired to an "intermediate"
nylon connector, and the nylon connector gets wired to the terminal strip.
The terminal strip also gets wired to the audio panel. Thus, to change
audio panels, I simply remove the wires from the terminal strips and run the
new wires to the terminal strips. TO change a radio, I simply wire the new
radio connector into one half of the intermediate connector and it is done.

The terminal strips all reside on a sheet of thin aluminum that is bolted to
the bottom of the radio rack. Why the bottom? Because if I'm having
trouble with a radio, all the connections to the radio are right there in
plain sight for troubleshooting.

I do not claim inventor rights to the terminal strip idea. I got it from
working on Baby Boeings. That is how Boeing makes connections. I do claim
inventor rights to the intermediate "Karmic Connector" idea. (Karmic is
what my editor at Kitplanes named it ... it stands for "Kitplanes Aircraft
Radio Middle Intermediate Connector" or some other hogwash like that.

As to your friendly local A&P, nobody ever said that they need to be looking
over your shoulder every step of the way. So long as you go in with a plan
that they can see, and that they can observe, and once you earn their trust,
you go in with the plan and they inspect the final product weeks or months
later.

Some tips: Get yourself a Mouser print catalog by calling them up and
asking for one. We dye the connectors to color code them for male and
female pins -- nylon will dye red, black, green, yellow, blue ... in Rit
fabric dye at room temperature in a couple of days, or in hot water in a
couple of minutes. Use crimp terminals on all the wires at the terminal
blocks. A plain old ten dollar crimp tool can make every bit as good a
connection as the $150 ratchet crimp tool. When you put the male and female
pins on the wires for the nylon connectors, crimp AND solder them. Get a
shareware schematic drawing program for your wiring diagrams -- your
mechanic will be impressed.

Last ... you are wondering what second radio to put in. While you are
wondering, I have a perfectly good Com-11 that is gathering dust on the
shelf. You are welcome to borrow it until you decide, but a decent older
Narking radio on ebay is not a bad deal.

Finally, if you get REAL serious about this stuff and understand that I
won't be available to answer questions right away, and as I understand it
you live in Georgetown about 20 miles south of me, I'll take on the
inspection job IF you report blow-by-blow progress to this newsgroup. I'll
even loan you the schematic drawing program with a couple of samples from
the 182 files. It would be nice if we could figure out how to ferry the
airplane up to Grass Valley for the inspections, then you fly it home with
the signoff (or a list of squawks to clean up).

No matter WHOSE audio panel you use, or WHOSE radio you use, it will be
absolutely mandatory for you to find a pinout of the connector. A good
starting place is Bob Nuckoll's page at www.aeroelectric.com .

Interested?

Jim

(Jav, ya wanna chime in here?)


"three-eight-hotel" wrote in message
oups.com...

Thanks, so far, for the responses... I'm not ignoring them, just
digesting them... ;-)

I'm not afraid of getting my hands dirty, but am thinking about the
implications and the logistics of going down that road. Evening and
weekends are really the only times I would be able to work on it, and I
don't have any friends that are A&P's or IA's. My mechanic and another
mechanic I know would not likely be excited to help me on evenings or
weekends, just so I can save money.