Maybe the active TCAD doesn't transmit on the ground (airspeed or squat switch sensitive).  TCADs are supposed to ignore planes on the ground, but I don't know about interogating while ON the ground...

 

Matt

Interesting thought. I went to the marine antenna to solve all these issues but now this opens up another box. However, I think it just ignores the ones on the ground, you still see the airplanes in the pattern so I think it is pinging still. Hope someone who knows how the TCAD transmits lets me know?

Thanks,