Even better, try an antenna analyzer like an MFJ-269. It can measure the
impedence of the antenna system, including the coaxial lead from the radio.
If there is a problem with the lead, it can determine the distance to fault.
It can also measure the loss in a given piece of coax.

If you're anywhere near Knoxville, TN (Chilhowee Gliderport), I have one and
would be happy to hook it up and check it out for you. Otherwise, most
avionics shops have this kind of gear.


Mark


"Heinz Gehlhaar" wrote in message
...
Ken,
I would carefully trace the "goodness" of the antenna lead from the tray
to
the ship. A short or on open would get your symptoms.
I think a simple Ohm-meter would work. With the radio-to-tray connection
disconnected, you should see almost an open-ckt (meg-ohms) from the ship's
antenna to cable shield/ground. And you should see a closed circuit from
the
antenna to the coax center-conductor.
Good luck.

Heinz