/sdrx

Software defined multi channel AM receiver based on R820T(2)/R860 RTL and Airspy dongles.

Primary LanguageC++GNU General Public License v2.0GPL-2.0

sdrx

Build CodeQL

sdrx is a software defined multichannel narrowband AM airband receiver that uses R820T(2)/R860 based RTL-SDR or Airspy Mini/R2 dongles as it's hardware part. sdrx is written in C++ (C++-20) and regularly tested on a x86_64 machine running Fedora 40, on a Raspberry Pi 4 Model B 4GiB and on a Raspberry Pi Zero 2 W running the latest Raspberry Pi OS (mostly the 64-bit version). Audio handling is done with ALSA.

Dongles used for the development are: RTL-SDR Blog V3, Nooelec NESDR SMArt v5, Airspy Mini and Airspy R2. The program only support R820T(2)/R860 based devices and may be incompatible with other RTL dongles and less powerfull Raspberry Pi models. YMMV.

The new R828D tuner based RTL-SDR Blog V4 dongle is not tested with sdrx and might, or might not, work.

sdrx is a text console program intended to be run from a terminal. Basic Linux understanding is expected from the user, especially with respect to how to run programs from the command line.

The channelization is currently done with a translate, filter and downsampling approach in the time domain. This is simple, but not the most efficient way when listening to many simultaneous channels. Other methods are being considered in the future.

Features

Below is a list of the current main features of sdrx:

  • Multichannel. Listen to multiple channels simultaneously
  • Airspy R2/Mini and R820T(2)/R860 based RTL dongle support
  • Up to 8MHz of RF bandwidth (Airspy R2 or Mini in 10 MS/s IQ)
  • Per-channel auto SNR based squelsh
  • Auto restart of dongles if they are unplugged and then plugged in again
  • Audio panorama. Places your channels in a virtual left-right audio panorama for increased awareness
  • Proper airband channel designators instead of frequency. Supports both the 8.33kHz and the 25kHz naming schemes
  • Full individual control over the R820T(2)/R860 gain stages (LNA, Mixer and VGA)
  • Channel based waterfall (-ish) in the terminal

Download and build

sdrx is only available in source code form. It is easy to build using the instructions on the build page.

Using

Instruction for how to run and use sdrx can be found on the usage page.