I have had a Terra 760D in my glider for the last 10 years. It works
great nearly all the time except when I fly in our soaring regatta in
Central Idaho. It has always recieved great but when I start flying at
High Altitude were we typically fly between 14,000 and 18,000 feet the
tranmission occasionally becomes unreadable. I suspect this is some
combination of the batteries getting cold (low voltage) and possibly
the radio itself not liking the altitude. After a couple years of
consistantly having trouble I performed my own informal survey. We
have up to 15 different gliders flying in these regatta's and the
after listening to different radios I determined that only the Dittles
and the Beckers consistantly performed well (with clear
transmissions) in this High altitude enviorment. This year I
installed Becker and am very pleased with it with everyone giving the
transmission quaility a thumbs up. I remember that the MicroAir
miserably failed my informal Survey and the ATR was suspect (due to
the pilot often failed to respond, I don't know if this was the pilot,
the reciever or the transmitter). I don't recall what other radios I
evaluated.

Brian
HP16T