On Wednesday, January 20, 2016 at 2:09:34 AM UTC-5, WaltWX wrote:
I had recently equipped over the previous winter with a Mode S transponder (Trig T22), I was curious whether: 1) It was working... 2)Did the FAA use my target to call traffic.

Turned out the answer was yes! to both questions.

I've a Trig T21. An ATC controller told me that I might be filtered/deleted from his display when circling or flying in wave due to my low ground speed.

Does your display on the radar have anything to do with the low traffic where you were flying or ATC knowledge of glider traffic in that area?

More generally, I'd like to have a better idea of when a Mode-S equipped glider is visible to ATC and when it is not visible.