Steve wrote:
HL Falbaum wrote:
I have used a Telex handheld with a plantronics headset and PTT; and an Icom
A22, Headsset adapter, David Clark headset and PTT without problems, and no
special setup.

Could it be something in the glider? Have you tried the setup away from the
glider--a longshot of course but easy to test.

A broken shield to ground solder joint is not an unusual occurrence and
could happen in two sets.

Good luck

--
Hartley Falbaum

"Steve" wrote in message
ups.com...
I'm currently using a Vertex VXA-300 and have a Pilot-USA headset:

http://www.pilot-usa.com/pa2011.htm

While transmitting, there is pretty bad feedback (high pitched squeal)
in the headset. After doing some searching and trying a couple of
other headsets, it seems that the problem is that the radio is feeding
the transmission signal back into the cables and causing feedback.

Another member of our soaring club has the same problem with his Icom
using a Telex headset.

After doing quite a bit of research it seems that this is a common
problem with handhelds and headsets:

http://www.avionicswest.com/articles/a23.htm

We've both narrowed it down to the interference from the antenna but
cannot find a sensible way to solve the problem other than to
physically wrap the headset adapter cable around the antenna! This
solves the problem for both of us.

I contacted Vertex and they tell me that this will reduce the
transmission capabilities of the radio. They want me to send the radio
in and have it diagnosed saying that it may be a fault in the headset
adapter or radio, but I find it difficult to think that two different
people with two different radios and two different types of headsets
could have the exact same problem and resolve it in the same manner.
It also concerns me that this is a common problem and nowhere do any of
the handheld manufacturers mention it.

Just curious if anyone has any information or possible solutions.

Thanks,
Steve


I suppose it's possible that there's a bad connection somewhere in the
wire but in the article I posted the author talks about the
susceptibility of handhelds to send feedback through the headset.

The other person and I have done all sorts of testing and for both of
us, the problem is only eliminated by chaning the relationship of the
wires to the antenna which is what caused us to suspect feedback in the
first place. We initially did our testing while not in the glider and
both did further testing at home.

If the ferrite core doesn't solve the problem, I'll send the radio back
to Vertex and see if they can come up with a solution.

Thanks,
Steve

Just wanted to post that the ferrite core with one turn of the wire
completely solved the problem! Woohoo!!! No matter how I orient the
radio or leads, there is no feedback.

Thanks so much Colin for your help. Finally, I can use my headset with
my handheld without killing everyone's ears, mine included.

Going to get a bit of shrink tubing to keep the ferrite in place and to
dress up the lead a bit. I think I may write up an article with
pictures and post it to my personal website for reference so that
anyone else having this problem will be able to fix it.

Thanks again,
Steve