On Oct 14, 2:29*pm, Andy wrote:
On Oct 13, 9:17*pm, SD wrote:

I am hoping someone can help with a problem I am having in
mySZD55.while thermaling some transmissions are lost as I turn.it
seems to recieve fine no matter if I am turning or not.it's an older
avionic dittle 720c.how do I diagnose if it's antenna related or just
a bad radio?
Thanks, Dennis Vreeken. aka 4Q

If you recieve ok with a given aircraft attitude and heading but do do
not transmit at the same attitude and heading then the law of
reciprocity rules out an antenna problem. *An antenna system works
just the same for receive and transmit.

You can expect the antenna performance to change as you circle.
Whether you receive ok depends on the received signal strength and
your receiver squelch setting. *Whether *others hear you depends on
their received signal strength (which will vary as you circle while
transmitting) and their squelch setting. *What you are experiencing
may be completely normal. *Try setting squelch off or at minimum at
both receivers and see if you can detect a slowly varying signal or
sudden loss as you circle.

I don't know of any aircraft VHF tranceivers that provide an S meter
but when I built my RST years ago I brought out the AGC line so I
could do signal strength tests.

Andy

I had a similar problem just this last month. I had a bad push to talk
switch on the control stick. Seems I had to really push hard on the
button to transmit. Replaced the switch and it now works OK. This was
in a SZD55 #096 N55SZ. Hope this helps, Paul