On Tuesday, December 15, 2020 at 11:56:33 AM UTC-5, Dan Marotta wrote:
On 12/15/20 3:02 AM, 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.

Good information about the firmware. I had to send the control head for
the TT22 in the Stemme to the avionics shop for upgrade. There was no
charge for the service IIRC.

--
Dan
5J
Thank you all for the help and information, as wel as the link to the original article. We're considering installing a trig22 with ADS-B out for or glider, which also happens to be a DG303 as in the article.
Thanks