A tutorial on using RDS Spy with the SDR# MPX Output Plugin

Over on YouTube user pe1etr has uploaded a tutorial video showing how to set up RDS Spy and SDR# for monitoring RDS. RDS stands for Radio Data System and is a sub carrier added to some FM broadcast signals which carries information such as the station name, the song/programme playing and other data. Although SDR# decodes RDS stations already, a more powerful RDS decoder and monitoring tool is RDS Spy. To get RDS Spy to work with SDR# you need to use a special plugin called MPX Output, which allows SDR# to output audio that includes the RDS subcarrier, which can then be piped via a virtual audio cable to RDS Spy.

Pe1etr’s video shows how to install the MPX Output plugin, how to set it up with virtual audio cable and how to use it with RDS Spy.

Tutorial: Using RDS Spy with the SDR# mpx output plug-in


  1. Peer-Axel Kroeske

    The MPX plugin / RDS Spy also works without a real 192 KHz soundcard. I use VB-Audio (free donation ware). http://vb-audio.pagesperso-orange.fr/Cable/
    Download the Hifi version. In the mixer settings / properties select similar 192 KHz parameters for both playback AND recording. When selecting VB-Audio in SDR#, there seems to be no difference between MME and DirectSound. With VAC I did not come too far but maybe it’s also possible with the right settings.

  2. Sergio Navarro

    Maybe someone want to try my plugin for SDR#. The connection with RDSSpy is through socket TCP/IP ( No virtual audio cable). You have to add manually the line:

    in Plugins.xml file in your SDR# program directory and configure RDSSpy for TCP/IP connection with IP host: localhost and port: 23
    Also you have to copy the file RDSOutput.dll in your SDR# program directory and rename it to
    SDRSharp.RDSOutput.dll .You can get the file RDSOutput.dll from:
    No need to compile it, get the file from RDSOutput/RDSOutput/bin/Debug/ directory.

  3. jay james

    while i am all for demodulation of any and all RF data whenever possible, i have myself never seen anything more than a station ID or song name in an RDS capture. i am not saying theres not anything else being transmitted, but spectravue will do this as well, just remember to turn off 2d color graph in general setup options to give it a shot. besides, i always wondered what that MPX subwindow was for in SDRsharp 🙂 great work.

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