Software DVB-S demodulator

  • Hi, this has nothing to do with yor CPU, i'm having the same problem. The PlutoSDR uses libiio, which is a piece of software by Analog Devices handling all the USB stuff. but the problem is, that i need to poll the data, which means, that i need to ask it for a new chunk of samples. If i don't manage to do it frequently enough, there are lost samples. And that's the worst thing that can happen for a DVB-S demodulator...

    There are many reasons for this problem. It can be the operating system not scheduling the thread often enough which does the polling. That's the case on high CPU load, or if there are peaks in CPU usage. Of course, this is an important problem, which i need to find a solution for. A temporary solution could be using lower samplerates. That improves things a little, but it doesn't fix the problem. I recommend other SDRs at the moment until i come up with a solution. As far as i know, the PlutoSDR and LimeSDR have this problem. I'll keep you posted on this.

  • hi tony, you have those braces [ ] below the [Generic] line. it won't work that way. change the ui_iqplot line. If oyu want to comment out a line, use the # character at the beginning.

    As an alternative, you can swap the [...] lines. But Generic needs to be the one just above the options.

    perfect thanks it works correct [ to # thanks for your suggestion

    ik1hgi Tony

  • I'm hoping to use DVB-S2 Demod GUI with my Pluto for DVBS-2 on 71MHz and 146MHz. Both my Plutos have been expanded to 70MHz-6GHz (Tested on SDR# so I know they work) but the lowest I can tune my Pluto in DVB-S2 is 325MHz? Am I missing something basic?? If I enter 70MHz before I open the device it then jumps to 325MHz when I do open the device?

    My RTL dongle works as expected but my RSP-1 does not? I thought it was supported?

    Guidance welcome - thanks.

    Gareth G4XAT

  • Hey Gareth,

    I can tell you its works, no problems with the sdrplay-1!!

    see here the solution..


    I have done this for solve the problems with the RSP1

    Install :

    API/HW Driver – v3.04 (9th Jul 2019)

    (now it download the newer version automatic v3.06!!!)

    Instal it in the same map were you placed the DVB-S Demodulater...

    open the map and you will find a "SDRPLAY" map

    Open it...

    Open the map API...There you will find x64 and x86....(64 and 32 Bit pc!!!)

    open the map and find "sdr_play.api and lib"

    Copy both to the dirctory of the DVB-S DEmod

    Greetings ON7KEC - Luc

  • Thanks Luc, that is now working fine :-)

    Just to solve the Pluto tuning range now, although the RSP-1 has slightly better 'ears' than the pluto but it would be nice to have both available.



  • idd Gareth the sdrplay is mutch better than the pluto..

    I'm a little disappointed in the pluto

    The dvb-s2 software runs very good with sdrplay and even rtl stick...buth with the pluto i'ts a other question...

    And it is not Marko's fault , he does a great job of making it works with the pluto also.

    Greetings Luc