As Dan had pointed out to me in an e-mail, if you use the software switch in the transponder and are flying in wave or against strong winds, it would show you as on the ground while you are at altitude. The software switch is based on GPS ground speed. Not good. So I will be installing the hardware airspeed switch.

Bruce

For experimental gliders fly in 'adsb airspace' after 2020, the Trig website guidance (below) is to use an uncertified puck gps antenna, TN72, and TT22 with SIL=3 setting. Also an 'airspeed switch', but they aren't clear if this must be hardware or can be the software setting of the TT22.

https://www.trig-avionics.com/librar...ust%202018.pdf