Looking for software for HF RTLSDR reception with Pi


Hi John,

I had similar experience with GQRX on Pi 3B+. Reducing the sampling rate to 1Msps or lower helped somewhat, but it was still not stable.
For HF, I built a homebrew downconverter using a diode ring mixer and 48MHz canned oscillator. Also tried FST3157 KISS mixer, with even better results.
For demodulation without GUI, CSDR utility works great. CPU usage is in single % range, and the temperature stays low.

73, Mike AF7KR


Hi All,
I have a Pi3B+ running with GQRX and it works, BUT it's really hammering the CPU AND GQRX seems to be only a VHF+ application.  Running GQRX on a local FM station, the CPU temp rises to 80C and then throttles. There's a small heat sink and it's running caseless.   CPU load in this application is ~50% . I know that a fan will help a lot.

Question 1- is this typical?
Question 2- is there another package I could run that would give me HF capability as well as the VHF/UHF of GQRX? 

I have a Pi4 4GB that I could use too, but I'm surprised that the 3B is not capable of the function. I really don't need the real time waterfall, etc. but I would like to be able to monitor specific frequencies over extended periods of time.

Thanks for any help!
John K5MO