Thanks Neil for all the trouble you have gone to.
I am a tad dim on what the transponder actually does (something about being interrogated/responds with ID/Alt/Location/Heading)-
Trig TT22 (ModeS) new (like aircraft), been professionally set up/certified, so all should be okay. I just turn it on before TO and assume all will be well..
I have three GPS systems, operating in the aircraft . As far as I know, none certified.
In my current aircraft I have only had one instance when ATC contacted me (had to SQUAWK CODE given) .
In my last, I had several instances where ATC either contacted me or more often, contacted other aircraft (usually IFR) to warn them of my presence.
I have a panel mounted iPad Mini with OzRunways & extra GPS antenna, so have some traffic displayed.
If I understand you correctly;
The Skyecho could be configured to work on ADSB IN (only) & "paint" onto my iPad, any ADSB OUT aircraft, within a 20 NM radius of my position. Without ADSB OUT I would not appear on other aircrafts systems.
I am confused about using Skyecho IN/ OUT with TT22 also operating - is this functionally okay or not?
I could just get a PingUSB from UAvionix. This will display ADSB IN on my iPad but as no OUT capability, would be as for Skyecho above.
Seems to me that if Skyecho & Trig TT22 can both be active at the same time , this would be the way to go.