On Wednesday, September 27, 2017 at 10:24:48 AM UTC-7, son_of_flubber wrote:
I asked Trig support this question:

"Will a TT21 + TN72 transmit a non-zero quality indicator?"

Here is their reply:

"The TT21 is fully certified to the latest ADS-B Out cert TSO C166b – so it can output all the required data. It is true that if you wish to meet ADS-B Out compliance FAR 91.227, you should have a higher power TT22. However, there is no way for the radar to tell if you’re using a TT21 or TT22. Inspection of your aircraft would be the only way to tell. As such I believe a number of experimental pilots have opted to ignore the requirement , but of course I cannot recommend this as it would be in violation of FAR 91.227 – the requirements for 2020 compliance.

The TN72 offers both a SIL =1 output, and also a SIL = 3 output. So this means that you can meet the FAA compliance check using your TN72 plus TT21. https://adsbperformance.faa.gov/PAPRRequest.aspx

If you so choose, you can opt to have your TT21 upgraded to a TT22. For more information on this please contact our US service centre below;

Trig Avionics Technical Support
9400 East 34th Street North
Wichita
KS 67226
United States

Tel: Toll Free 800 821 1212
Tel: +1 316 630 0101
Email:
Web: www.mcico.com
"

The response to my inquiry with is:

"The cost to update the TT21 to the TT22 is $950.00. Turn around time is 3-4 days in house."

That is some very useful information right there. Two questions:

Does the receiver (FAA) have any way to tell more information about the GPS source? If it is transmitting an SIL of 3 (required for carriage requirements), other than physical inspection can a receiver discriminate between a 70 and a 72?

What does Powerflarm do with a glider having both ADSB out and Flarm? Does it deambiguize?