Hi Alan,
Certainly no ADSB reports on your second screenshot, despite your unit having been running for almost 2 hours. You say you were flying with a colleague running SkyEcho. My GT has full ADSB out via a Mode S Transponder and PilotAware. I also have a SkyEcho, though for obvious reasons I don’t use it very often (mainly for testing or if flying an unequipped aircraft). It does however give me a good knowledge of how SkyEcho operates.
I had an interesting experience a couple of weeks back visiting a local airfield, where an acquaintance reported that his aircraft which was running a SkyEcho was reportedly not showing on ADSB. Checking his SkyEcho setup using the uAvionix app, it turned out that he had Vso set at 90 Knots - which means that SkyEcho won’t start transmitting until his aircraft exceeds that speed. Worth getting your mate to check his settings just in case.
My other thought is that a problem might have developed with your 1090MHz antenna or cable. This can be easily checked by replacing the antenna and cable by a length of thin wire (bare wire or thin electrical cable). Anything will do as long as it is thin enough to fit into the centre of the RTLSDR dongle antenna socket. Just make sure it isn’t short circuiting to the outside of the socket. Even a thin paper clip bent straight is enough to receive strong ADSB signals from commercial aircraft.
Give it a try and let us know how you get on.
Regards
Peter