Transponder installation article- Soaring Magazine

On Tuesday, December 15, 2020 at 6:51:42 AM UTC-5, wrote:
After installation and testing are complete, take a flight and the check your FAA performance report he
https://adsbperformance.faa.gov/PAPRRequest.aspx

Mine flunked the first time. I had one of the configuration settings wrong, but it was easily sorted out with information provided by Prof. Pfiffner:
http://www.craggyaero.com/tt22_tn72_settings.htm

Cheers,
...david
On Tuesday, December 15, 2020 at 5:02:52 AM UTC-5, wrote:
A few random notes from my TT22 installation:

- From the Trig Installation Manual: "The transponder power input is not protected against reversed power connections. Reversing the power and ground inputs to the transponder will destroy it. Check wiring before applying power."
-- A proven hazard demonstrated (luckily) by someone else

- Common sense for all transmitters but not obvious on a transponder: Make sure the antenna is connected before any transmission takes place. When is that? Generally, anytime the transponder is on GND, ON, or ALT switch mode and it gets and replies to an interrogation. SBY mode use (e.g., for initial TT21/22 SETUP programming) should be OK without having the antenna connected. But it's easy to mistakenly turn past SBY onto one of the "transmit" positions. So it's best to have the antenna connected before powering on..

- If you plan to have ADS-B Out by integrating a Trig TN70 or TN72, both the firmware on the TC20 control head AND the main transponder (TT21/22) must be of a certain version number or later (like v1.14 and v2.12, respectively). An authorized Trig dealer can confirm the current requirements and upgrade your firmware as needed.
-- The firmware versions are displayed very briefly on the control head screen after powering on. I video'd the sequence and replayed it several times to catch the numbers.


I am thinking of installing a TRIG xponder for next season, maybe with ADS-B, but this would mean installing multiple GPS antennas (FLARM, C302, Xponder) and I'm running out of room under the glareshield.

Questions for the experts out the need there be a minimum spacing between GPS antennas (i.e. do they interact); and is there a way to connect one GPS antenna to feed one or more boxes?

Thanks!
Ian IN