You aren't being filtered out by airspeed or code. Read the posting by
Billy Hill. Your transponder is being seen by ATC, the airliner TCAS, and
everyone with a TPAS unit, so I think your $2000 was a good value (that's
what my Becker cost me, too). We still have to worry about all the other
gliders (even those with a transponder, because I don't have a TPAS unit
yet), and some/many of the small airplanes, too.

Eric Greenwell - Washington State, USA

Hmm.....well maybe you missed this above from jettester Eric or he's
incorrect.....

Tom;
I am a FAA Test Pilot who is authorized to test Transponders in new
aircraft... I do this for a living. I also was qualified as a Hawker
800XP test pilot.

Bottom Line - Transponders are NOT the answer! Try putting one of
these new LED Strobe Lights on the top of your Fin instead.

#1. Transponders would not solve the mid air problem unless you were
the only one in close proximity to the attacking aircraft. Typically,
they set MTI (moving target indicator) to above 60K or higher
(especially if near a large amount of highway ground traffic), so once
you start thermalling they lose you unless you are given a discrete
squawk other than 1200 (for non participating VFR Traffic)

#2. If multiple gliders (or aircraft) are in the vicinity all
squawking 1200, ATC could not tell one from the other. Mode C (if you
have it) reports altitude, yet if the climb or descent rate is large
(let's say greater than 1500fpm) their equipment typically faults you
off the scope and does not report your altitude. Once again unless you
are given a discrete squawk other than 1200 (VFR traffic).

I also have a Becker and will continue to believe that its better than
nothing......

KC