Confusion over SDR# vs OpenSDRSharp

As you may have noted in our previous posts, there exists an excellent piece of software written for use with the RTL-SDR dongle known as SDR#. If you’ve tried it you know it’s incredibly user friendly and provides immediate, full-featured use of the RTL-SDR dongle out-of-the-box. The only downside, of course, is that it’s developed for Windows since it’s written in C#. (Linux users report success running it under Mono.)

According to a blog posting on Reddit RTLSDR, there appears to be an attempt to subvert the SDR# user base with allegations that SDR# was somehow violating the GPL by embedding RTL-SDR support in the download, and that SDR# can no longer be used with the dongle.

Youssef, the developer of SDR# has countered that any licensing questions have been resolved between himself and Osmocom and changed the download structure accordingly. He also opines that the attempt to divert users from SDR# to some forked project may be an attempt to spread malicious code in the growing SDR community given the popularity of the RTL-SDR dongle.

You can read Youssef’s position in full on the SDR# downloads page.

So what does this mean to the average SDR#/RTL-SDR user? Well, for starters, you can NOT just download the latest nightly build, unzip, double-click the executable and expect to use the RTL-SDR dongle as you’ve become accustomed to. It simply doesn’t appear in the Front End selection box. So what to do?

Simply click on these links for instructions on using the latest builds with Windows or under Linux (using Mono).

After reading the above and linked content you can make your own decision about which RTL-SDR project you want to follow, but given his track record Youssef’s SDR# looks like a winning bet.

Keep up the outstanding work Youssef. SDR# is one of the best open source programs this year.

This entry was posted in Editorial, open source, RF, SDR, software and tagged , .


  1. Zeke D says:

    Was unaware of the drama. Four new dongles arrived for my peers to play with and my old instructions caused some grief on getting things going. Rolled back to an older release folder and passed it around, all is well.

    Made some front end filters and a nifty SBL-1 / 100MHz XTAL upconverter for the lower frequency goodness. Trying some ethernet streaming using BorIP, for carrier level monitoring as well.

    I don’t think it is even possible for Youssef to really know how much his efforts are appreciated and the long lasting impact it has.

    Yeah I know. Don’t hate.

  2. Winston says:

    I’ve looked at DP’s SDR links and didn’t find listed the following very active community for inexpensive SDR experimentation, so I include them here:

    and some of the kits related to the above group:

  3. makomk says:

    No kidding there was drama. The GPL was created with the explicit purpose of prohibiting people from using GPL-licensed code in the way that SDR# is using the GPL-licensed librtlsdr; it’s the entire reason why it exists. What’s more, Osmocon can’t give permission to SDR# to ignore the actual terms of the GPL and do what they like because they didn’t create all the GPL-licensed code within librtlsdr and don’t own the copyright on it.

    • Fred says:

      So if I release a plugin under GPL for some software, say MS Excel, does it make the entire software GPL? AFAIK, SDR-Sharp existed way before Antii discovered the SDR function in RTL chips. The software can effectively interface to any existing front end using plugins, GPL or not. Also, Osmocom have prevented Antii from using his discovery in his Master thesis as they took over his GPL project and released their lib based on his work. Not good. GPL folks try to take over anything that has substantial value. However, this doesn’t always work as expected. Our anonymous “GPL Jihadist” delta1212 has disappeared in the wild after having failed to GPL’ize SDR-Sharp.
      BTW, having tested the program I can confirm its MSRSL part (the DSP) that started all these problems is much higher quality than any GPL stuff I have come by under either Windows or Linux (Have you tried to do anything efficient with GNU Radio? GQRX? …)

  4. Fugu says:

    Does SDR# run on Linux or OS X? I don’t

  5. Larry says:

    Well, it appears that Youssef is accusing a developer of a similar app, found of Google Play of copyright infringement on his app but gave no proof to Google other than an accusation. Of course, Google being the nice folks they are, took down the “offending app” without any actual proof it was in the wrong.
    See here for more info:

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