On Aug 11, 3:54*pm, "John Scott" wrote:
I believe I started the thread storm about the TT21. *After having a United
737 pass directly below me by about 300'-500' while thermaling, I decided it
was time to install a transponder. *Since my plane is certified
Experimental-Amatuer built, I didn't believe I was constrained by the lack
of a TSO for the TT-21, so I ordered one, installed it, and had it certified
for operation.

I have been very happy. *I've seen airliners routing around me on several
occasions since install it. *With an CA302 & *Tasman varios, Microair Radio
recieving, Oudie, and the TT21 replying to queries while sitting on the
ground, my current draw is about 600ma.

John Scott

I know John knows this, but to be ultra clear to others the Trig TT-21
has since received TSO approval for a Mode S transponder.

BTW like most ADS-B data-out devices currently in use its currently at
the old "-A" standards level and I expect a firmware update to make
them "-B" (i.e. DO-260B) complaint to meet the FAA carriage mandate.
Trig also tells me that firmware updates will an indication that the
GPS source is feeding the ADS-B and the ability to set the transmitter
capability code bits to describe if your aircraft has a UAT or 1090ES
receiver. Currently you can only set the "1090ES" bit. Trig gets
credit for making that setting so easy to do, its not clear other
transponder vendors are/will be.

In addition to the FAA flying Trig transponder for ADS-B survey work I
though that there was at least one Trig transponders flying in a
glider with 1090ES data out today but since the pilot is being quiet
maybe its not. I do know several owners interested in playing. The
hold up on the west coast is lack of ADS-B ground infrastructure and
anybody having an ADS-B receiver to play with. I think once some geeks
get PowerFLARMs in their hands there will be more reason to play
around with the TT-21 and ADS-B data-out.

Darryl