(Snowbird) writes:

OK, here is what I don't understand:

We have this problem with the airplane's master switch turned OFF

Can the receiver's RF amp generate intermod products when the
power is switched OFF?

Yes. All it takes is a non-linear device, i.e. a diode.
Iffen the tranceiver used diode-switching in the front
end, and there's enough RF to make the diode conduct..

The trouble is, a diode can also be one slightly corroded aluminum
joint.

If the antenna farm itself is generating intermod products,
can it be picked up by an installed antenna (connected to a
receiver which is turned OFF) and re-radiated to our comm
antennae?

It's now sounding like the non-linear junction is on your airframe
somewhere.


It's not that I'm unwilling to disconnect all the antennae in the
plane, but some of them are a terrible PITA to reconnect and I'd
like to understand the theory of what's supposed to be happening
to produce this problem with the power to all of the receivers
turned OFF.

Well, first fly the handheld in another airframe. That establishes
iffen it's part of the solution or the precipatate.

If all's clean in that case, start looking at all grounds on yours.
Disconnect the easy antennas first.... and see if anything changes.
Keep good notes!

If all else fails...http://www.spacemodel.com/pic355.html

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