On Jan 11, 2:40*am, wrote:
I'll see if there's a good shop at the local airport(s).


You may get lucky, but you may spend a lot on a "by the hour" bill and
get nothing in return.

Under and overmodulation of the radio is most likely due to an
incompatible microphone or an incorrect adjustment of the modulation
level pot. You can easily tell if you have an over or under
modulation problem. Undermodulation will give a weak but clear voice
but overmodulation will give a loud and distorted voice. If loud and
distorted just speak quieter and see if the distortion goes away. If
it does then adjust the modulation pot. If weak voice increase the
pot adjustment.

If someone listens to your transmission do they hear a difference in
voice quality when you use a different antenna at the glider ? (you
can plug in a mag base whip for the test)

First thing I would check with the glider antenna is the quality of
the coax connector. Was it a crimp on one installed by the factory or
was it installed after delivery. It's unlikely to be an antenna
problem.

One reason for audio distortion may be that your radio is slightly off
frequency. You can find out by doing a zero beat test using 2 other
radios, one transmitting and the other receiving both. But try this
test last if nothing else works.

If you can get in touch with a local radio amateur who is also a
glider pilot you should have all the expertise and equipment you need
to find your problem.

Andy