In article ,
(John_F) wrote:
2 -- Noise is WORSE when any radio, but especially marker beacon, is
selected on the audio panel.

The noise is coupling into the marker beacon audio. Is the marker
beacon ground connection the same point as the strobe ground? Is the
marker beacon audio lead shielded wire?

I don't know the answer to either question off-hand, but I do know that
the marker beacon receiver is on the shelf in the tail that is not too
far from the strobe power pack.



VERY VERY BAD!!! This is how the noise is coupling from the strobe
power leads on to the audio leads if they are in the same wire bundle.
ALL of the audio leads MUST be shielded wire.

Yes, I know that this is bad, but it probably could be worse (and
remember, I'm not responsible for the intercom installation). The leads
to and from the intercom don't appear to be bundled with the strobe
power leads, or even close to them. I am hoping that this isn't the big
problem, and I can let this ride until I have the interior replaced and
then replace the wiring at that point.



Find a avionics shop that knows what they are doing and have them fix
it. They are very hard to find and generally will NOT have the lowest
rates but they will generally save you money.

I don't want to give someone a blank check to troubleshoot a problem
without some idea of what it may be. In other words, I need to try to
troubleshoot as much as possible before engaging the avionics shop for
more in-depth troubleshooting. I do believe that I have a good avionics
shop in the local area, and they've done work for me before, but I
haven't classified this problem as more than a nuisance at this point.
However, it may be getting worse, and I certainly don't want it to reach
a point where it becomes a show-stopper.


JKG