On Saturday, May 19, 2018 at 3:12:04 PM UTC-6, jfitch wrote:
For those of you contemplating this, I've made some rough power measurements. Sitting in my shop with a clear view towards the airport, the TT21 is reporting nearly constant interrogations, and drawing between 120 and 150 ma. The TN72 alone draws about 70 ma. When both are powered and broadcasting ADS-B, the power is about 170 - 210 ma. All measurements taken with a clamp on hall effect sensor, +/- 10ma. So roughly, the extra power to transmit ADS-B is lost in the noise. The TN72 takes measurable power, but not much. This is a pretty cheap way to make yourself seen.

Not related to power consumption but still of possible interest to those of you trying to make this ADS-B out system work for gliders. I have been in touch with Darryl and Jon via email since I was unable to configure my TT22 and TN72 properly. My settings worked in that the FAA was able to send me a "Performance Report" on ADS-B out after a long flight but it was full of red boxes and con-compliance stuff. I talked to Midcontinent Avionics and they finally came back with a good reason for all this. I had sent the "core" of my Trig TT22 to them for a required firmware upgrade which they performed quickly and at no cost (except for shipping). I now heard from them that the "head" (display and function input) of the TT22 also has to be upgraded so that I can see the new settings options for the various and quite confusing combinations. Darryl had sent me settings that I never found when going through my device. With hindsight, I could have figured it out myself....
Still waiting for the proper settings from Trig and Mid-Continent.
Herb, J7