Trig TT22 transponder issues

When I first installed my TT22 about 3 or 4 years ago, I thought
everything was OK except that it failed the test. Closely monitoring
the display during startup revealed an error message displayed for such
a short time that I could not read it. I cycled the unit through
several power cycles reading the next word in the message each time and,
when I had the full message, I contacted Trig tech support. I believe
the engineer's name was Andy.

Andy told me that the message indicated a problem with the wire harness
so I took it apart (the end which I'd soldered on) and found one stray
strand of wire which was shorting two pins. I'm not saying this is your
problem, especially as you describe the temporal aspect of your
indications, but it certainly couldn't hurt to have a look inside the
connectors or even just ring out the harness with an ohm meter.

Good luck,
Dan

On 6/24/2017 5:10 PM, Echo wrote:
*Sigh*

I know how transponders work. No you don't get constantly pinged. Yes the plane is supposed to flash as it's being tagged by radar. No that's not what I'm talking about.

I meant to say text on lower left. Do you want a photo? It displays text: SBY/GND/ON/ALT corresponding to switch position. Mine works for maybe 20 minutes, then displays dashes where the text was. Same issue with a different hesd unit and transponder in my plane today. Starting to think it's the wiring harness, more specifically the data line connecting the head unit on the panel and the box in the back. Running dual batteries, both lithium...power supply shouldn't be a factor. Antenna shouldn't make a difference to the display. Still troubleshooting. Next step is to try another harness, and check mine for breaks and bad solders.

Jordan

--
Dan, 5J