QSpectrumAnalyzer is a Linux GUI for rtl_power which allows you to easily do wideband scans that are much wider than the RTL-SDR’s maximum bandwidth. RTL_power works by quickly switching between different frequencies and recording power values in each hop, then stitching them all together. A GUI for rtl_power can be used to display an FFT spectrum and waterfall for easy analysis.
Recently we posted about the release of rtl_power_fftw, which was a modified version of rtl_power. This modified version used a more efficient FFT library and reduces the acquisition time, which for rtl_power was capped at 1 second per scan. Essentially this means that rtl_power_fftw can do frequency scans much faster (though with less integration). In basic terms this means that you can now visualize large spectrum sweeps whilst having the waterfall look near real time.
Now QSpectrumAnalyzer has been updated to support rtl_power_fftw. To use rtl_power_fftw you’ll need to download and compile it yourself from https://github.com/AD-Vega/rtl-power-fftw. The compilation instructions are shown on the Github page, but you’ll also need to install the pkg-config, libtclap-dev and libfftw3-dev libraries first. Then once compiled in QSpectrumAnalyzer you can select the rtl_power_fftw binary in the settings.
The latest release of QSpectrumAnalyzer can be downloaded from https://github.com/xmikos/qspectrumanalyzer/releases.