three-eight-hotel wrote:
: Okay, so I hear you... but I think where my fetish lies is not with
: pulling new wires, but in making sure there is proper seating, in
: anything and everything I can get to. If what I'm hearing is that Coax
: and wires will have nothing to do with it, I will move on from that
: thought. I was thinking corrosion, rust, ??? on a coax connector, or
: connector anywhere (especially connector tray - radio), for that
: matter. Even you agreed that replacing the coax "may work" and that I
: would only be out a couple of bucks, worst case. Your description of
: cutting the coax at a 45 degree angle led me to think that you might be
: questioning the coax "connector" to radio or antenna or at least be
: keeping it on a list of suspects.

Coax isn't all that hard to replace, necessarily... BUT it can be a big pain
to route. It goes all the way to the antenna... likely a fairly long way. Soldering
the ends on (well) requires a pretty good knowledge of a soldering iron... not just
"which end to grab." Given that it's very unlikely to be that particular one, I'd
start with something else.

: My advice is to tune in a constant signal ... like an atis or awos and start
: moving things around briskly. When the signal fails or comes back after
: failure repeat the jiggle. Narrow down the jiggle area.

: I've been using the ATIS at SAC as my constant signal, and have been
: forcefully pressing the radio in and shaking it from side to side to
: see if I can get it to come in, so much so that the LED's dim on the
: radio as I'm pushing it in. That's never got reception to come back.
: As far as other things, which I assume you are talking about wires
: behind the panel, I can certainly give that a try, once I can figure
: out how to do that without putting my self into an unintentional
: unusual attitude. I'm 6'2" and about 2 bucks, so I can barely get
: behind the panel when the plane is parked safely on the ground, let
: alone 5000 feet and 100 kts.

The problem my mechanic's transponder had couldn't be induced by forcing the
radio around in the tray. It was a mechanical stop near the connector. Couldn't
really make it come and go. Of course it was further complicated by the fact that the
only way to check it was to test-fly it and ask local ATC if they could read ModeC (I
don't have a transponder interroagtor). For your COM, it should be easier.

Just as a thought... have you tried pulling out the squelch when you're unable
to receive? If you don't hear static when you can't receive, it's likely in the
wiring/connector from the radio/intercom/audiopanel/jacks. If you hear static but you
still cannot receive, then it's much more likely the radio.

: I REALLY do appreciate all of the input, and am not TRYING to be a
: knuckle-head about all of this! I'm just trying to interplote the
: input I am receiving and do things that are within my capabilities.
: And in this case, my capabilities don't seem to cover a very broad
: spectrum!

The biggest thing would be to try and make it happen on the ground so that you
can troubleshoot it. I'm not familiar with Narco's trays, but on the King ones, the
connector can be disconnected from the tray. Then you could play with that without
being stuck with the geometry of the tray. Basically, stop at the top and work
down...

-Cory

--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
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