GQRX is a simple, intuitive, small and fast Software Defined Radio receiver tool that runs on Windows, Linux, and even on Raspbian for the Raspberry Pi. GQRX is an open source tool that is powered by the GNU Radio and the Qt graphical toolkit. Here are some of the highlights from the gqrx.dk website.

Gqrx supports many of the SDR hardware available, including Airspy, Funcube Dongles, rtl-sdr, HackRF and USRP devices. See supported devices for a complete list.

GQRZ offers a number of features:

• Discover devices attached to the computer.
• Process I/Q data from the supported devices.
• Change frequency, gain and apply various corrections (frequency, I/Q balance).
• AM, SSB, CW, FM-N and FM-W (mono and stereo) demodulators.
• Special FM mode for NOAA APT.
• Variable band pass filter.
• AGC, squelch and noise blankers.
• FFT plot and waterfall.
• Record and playback audio to / from WAV file.
• Record and playback raw baseband data.
• Spectrum analyzer mode where all signal processing is disabled.
• Basic remote control through TCP connection.
• Streaming audio output over UDP.

I like to use GQRX on my Raspberry Pi's, specifically Pi 4 and higher where the preformance is really good.

To learn more about GQRX, visit the QGRX site and the Gqrx SDR Youtube site. Downloads are available at the GQRX website.