rfscan

A fast radio scanner for SDR receivers that you run as your own small server: on a Raspberry Pi or a PC next to the antenna, listened to and controlled in a browser on a PC or a phone. rfscan sweeps frequency ranges or a list of channels, stops on a signal, demodulates it (AM or narrowband FM) and plays it, then goes on scanning when the transmission ends. Digital voice (DMR, P25, D-STAR, YSF, NXDN and others) is played through DSD-FME. Local audio and a text interface in the terminal (TUI) are available on the computer it runs on.

[!IMPORTANT] Set the settle time for your receiver before the first scan. After every retune a receiver keeps delivering samples of the previous frequency for a while, from a few to over a hundred milliseconds. If --settle is shorter than that, rfscan sees signals in the wrong places and scanning does not work properly. The default of 20 ms fits an Airspy, not an RTL-SDR: an RTL-SDR needs about 63 ms with smaller stream buffers (--stream-args "bufflen=16384,buffers=64") and over 110 ms without them. rfscan --calibrate measures the right value for your receiver. An RTL-SDR also needs…