I’m receiving WSPR transmissions with a Raspberry Pi 4, GQRX, and WSJT software, with the RSP1a. After a few hours of continuous operation, I notice that WSJT is reporting about a 3 second offset in time. The Pi 4 is staying in sync with the network time, as expected. By unplugging the RSP1A from the Pi 4 for a few seconds, and plugging it back in, and restarting GQRX, the time offset on received transmissions drops to a more normal +- 1 second. Not sure if it is GQRX or the RSP1a. Need to test a bit more.
3 seconds is not an issue w WSPR mode, but is for FT8, my next step, since in FT8 the time windows are only 15 sec each. I tried and could not receive FT8 signals with the 3-4 second offset.
Has anyone else seen this phenomenon, and has anybody come up with a faster workaround than restarting the radio?
Thanks so much for any comments!
After some additional testing, the delay is in the GQRX software. Simply stopping and restarting GQRX with the button in the upper left corner (starts/stops DSP processing per the software) fixes the large time offset and it falls to 0-1 sec, probably normal for a SDR receiver. Also results in nice decoding of FT8 signals. My next step is to try transmitting and receiving FT8 with the Raspberry Pi 4 and a QRP radio.