RSPdx block diagram


  • This topic has 3 replies, 3 voices, and was last updated by .
Viewing 4 posts - 1 through 4 (of 4 total)
  • Author
  • #1620

      I find it really difficult to understand how SDRUno is controlling the RSPdx without a block diagram of the RSPdx with some description of how SDRUno is controlling it. It would be really nice if SDRPlay would make block diagrams of all the RSP devices available on their web site. It would then be nice if there where some description of how the SDRUno parameters are manipulating/controlling the blocks. A block diagram would also help in using the RSP device with programs such as gnuradio, where it really helps to know what the front end is really doing to produce the I/Q data.


        Hi rlkeck, unfortunately we have seen a number of fake RSP devices appear on the market and so now we don’t publish circuit or even block diagrams of the hardware. The published API shows the way the gain stages are set. See

        there is progress now on getting updated GNU radio source blocks.
        Franco Venturi is a key developer of GRC source blocks and author of

        Best regards, Jon


          Hi again rlkeck,

          this additional info may help…

          An important thing to know is that the RSPs work in gain reduction rather than gain. There are two types of gain reduction – IFGR (IF gain reduction) and RFGR (RF gain reduction). I refer you to section 5 of the API document – this will show you the RFGR range for each RSP. You will see that the range varies between each RSP and for different LO frequency ranges. The RFGR range is a value from 0 (min GR, max gain) to N (max GR, min gain). The tables show you the value in dB for each RFGR value. The RFGR is a manually programmed range, it is not affected by AGC.

          For each step of the RFGR range, you can also adjust the IFGR range from 20 (min GR, max gain) to 59 (max GR, min gain). The IFGR value is in dB and can either be programmed manually or controlled by the IFAGC loop. In most cases, you can set the RFGR and then allow the IFGR value to auto adjust via the IFAGC.


            I have just downloaded GNU Radio too and followed the official SDR Play video on how to set it up. I have an RSPDx and there is no option in GNU to make that a source block.

            It mentions about it coming soon in this article but that was last January!

            Does anyone know when it will be released or what i can do in the mean time to make it work ?

          Viewing 4 posts - 1 through 4 (of 4 total)
          • You must be logged in to reply to this topic.