For a couple of nights, I had my IC-9100 hooked up and listed to folks chatting on AO-85, but I didn’t decode a single telemetry packet. I suspected that the IC-9100 was filtering out the lower frequencies necessary for Data Under Voice (DUV) telemetry. A check on the AMSAT maillist confirmed my fears. “Don’t use the USB interface audio — decode from the 9600 output on the accessory jack.” Ouch. That sort of defeats the purpose of the single USB cable interface to the radio.
Plan B was to bring out my trusty FUNcube Dongle Pro Plus. Support for that SDR dongle is built into the FoxTelem decoding program. Sure enough, during a pass between 2308 and 2323 UTC, I was able to decode 11 packets. The first packet decoded was around 2314 UTC, and the last was at 2318 UTC.
The antenna is a M2 Eggbeater, but the preamp was not energized (normally it receives control voltage via the coax and the IC-9100). I should still be able to power the preamp using 13.8 VDC directly (I still have those cables in place), as it appears that diodes will block the voltage from coming back down the coax and damaging the FUNcube Dongle.
Setup couldn’t be easier. Select the FunCube Dongle as the input source. The sample rate and I/Q are automatically selected.
Nothing seemed to decode until I manually moved the cursor to the peak on an obvious signal around 145.980. Once I did that everything appeared to be fine and it seemed to track the frequency gradually going down from Doppler.
Experiment Telemetry indicates 7 packets received (out of 11)
Spacecraft Telemetry indicates 4 frames received (out of 11)
