ON4KVI and me had a great time this afternoon with QPSK 2400. Seems that 3600 is too wide for some radios. So with 2400bd it worked great. We sent files and messages as well as direct conversation. If you want to connect: The frequency now is 10489.980.000 , center frequency in soundmodem 1800hz. 1500hz seems a bit low for some radios. Use a wide filter for rx. Listen to the beacons, set rx-signal exactly on the markers in the waterfall, then set your tx-signal exactly on the markers in the waterfall. Also, carefully set DCD so it lights up when you receive a signal. If it stays off, your setup will TX while others TX and thus jam the signals. .
P.S. we might qsy to the Digital portion of the transponder later.