FreeDV via QO-100

  • Hallo,

    Sigi DG9BFC und ich hatten heute Abend ein längeres QSO in FreeDV über QO-100.

    Es ist schon erstaunlich was in einen 1/2 SSB-Kanal untergebracht werden kann.

    Wir haben die Software Version 1.3.1 von FreeDV genutzt und die Modi 1600, 800XA und 700D ausprobiert.

    Das Audiosignal war im 1600er Modus am Besten, immer noch recht "digital" aber sehr gut verständlich.

    Wir haben die Frequenz 10489.645 MHz verwendet.

    Sigi stellt aber zur Diskussion ob wir die 10489.640 MHz als "Anruffrequenz" für FreeDV etablieren wollen.

    Nochmals vielen Dank an Sigi mich zu dem Test zu und meinem ersten QSO in FreeDV überhaupt zu motivieren.

    Viele Grüße


  • Good morning friends.

    Thanks for learning!

    I googled several articles on the topic of FreeDV-2020 and found on the github that this version of the program is for Linux only. Does anyone have a compiled installer for Win 8.1 x64?


  • Greetings, colleagues, again!

    I ask for help from more advanced colleagues in Linux.

    Today I again heard prolonged “rustling” in a new form of digimod, but I did not have the opportunity to hear a live voice. I'm interested in listening to freedv 2020 live. I think that for windows the assembly will not appear soon.

    I have a desire to try to do it now. Therefore, you have to gain experience yourself, as it were, "in the blind."

    I googled a bit and found the following source pages:



    As a result of working at 1) after the line ./

    I have an error: There is no such file or directory.

    Then I tried to build the program from the source at 2). It seems that everything went well. But, I do not know what to do next. How to find and run the program?

    Now, like a blind man, I put my hands on the wall. I don’t know what to do next. Where to look for installed executables and how to run them?

    Any help is greatly appreciated!

  • #!/bin/sh


    #A Debian Stretch dev version of FREEDV automated script.

    #Save this as for example and do not miss give

    #executable flag on it and run.

    apt-get update

    apt-get upgrade -y

    apt-get dist-upgrade -y

    apt --fix-broken install -y subversion build-essential pkg-config cmake hamlib-dev libsamplerate0-dev libsndfile1-dev libspeexdsp-dev libwxgtk3.0-dev portaudio19-dev

    cd /usr/local/src

    svn co

    mkdir /usr/local/src/freedv-dev/build

    cd /usr/local/src/freedv-dev/build

    cmake ..


    make install

  • Hallo!

    FreeDV via QO-100 bringt mich an den Rand der Verzweiflung.

    Während ALLE anderen Digi-Modes von FT bis Hell funktionieren, ist hier Kein Decodieren möglich.

    Es hört sich an wie Fisch-Geblubber.

    Fehlerraten bis hoch zu 7000 plus X, keine klaren Linien im Wasserfall, links oben pendelt das S/N zwischen 0 u. 2.

    Benutze VAC, und das Versagen der FreeDV-Software findet sowohl bei HDSDR als auch bei der Console statt.

    Habe so ziemlich alles probiert, keine Abhilfe. Die Testfiles offline funktionieren dagegen tadellos.

    Evtl. Hat hier jemand eine Idee, woran die Decodierung scheitert (700er und 1600er,2020 läuft auf meinem NUC nicht).

    Ansonsten bleibt nur der Kick - Off dieser Software vom Rechner.

    73 de Bernd

  • Die Empfangsstation sieht folgendermaßen aus:


    Octagon-OSLO-LNB, 27MHz, Stabilisiert mit Leo-Bodnar-GPSDO

    SDRplay RSP1A auf SDR-Console, zusätzlich ist dort noch das Bakentracking aktiviert,

    Computer Intel NUC, 4x 1,5 GHz Celeron

  • Hello group,

    let me give you a short report on my tests with the LimeSDR and FreeDV.

    My setup:

    - SDR Console 3.0.19
    - Windows 10 on an old Q8400 Quad CPU - 2.66 GHz
    - LimeSDR Mini on a separate USB3-Card with power from the computer power supply
    - FreeDv 1.4
    - LimeSDR Mini operates on 50 MHz (replacing a KX3 that I usually use), signal is amplified by 30 dB and fed into a BU500
    - Filter between BU500 and PA to avoid that the LO frequencyof 2350 MHz is accidentally transmitted into space(attenuation @2350 MHz: >90 dB)
    - SG-Labs PA running at about 3.5 Watt output in the shack
    - 15m H-100 cable with a total loss of about 7 dB (including plugs)
    - about 650 mW at the antenna feed (5 1/4 turns helical antenna)
    - dish: Kathrein CAS 180, diameter 1.8m, offset dish
    - reception via Octagon LNB, xtal changed to have output signal on 70cm

    After my first LimeSDR Mini proved to be damaged (not recognized by Windows) I got a replacement which worked right away.

    My general observation is that my computer is far too weak to operate both, SDR Console wih LimeSDR mini transmitting option and FreeDV.

    Reception of FreeDV is not possible due to high frequency variation/jitter. All other digital modes work fine (FT4/8, KGSTV, ect.).

    Reception with a separate laptop and WebSDR works up to FreeDV 1600.

    FreeDV on the mainframe computer will transmit, SDR Console keeps transmitting but the screen will go black and sometimes will not return to its original state, so the program has to be re-settet.

    The LimeSDR Mini has the tendency to freeze, this has also been confirmed by Simon, G4ELI, the author of SDR Console.He has even threatened to stop support for this device.

    Conclusions and solutions:

    - the chain LimeSDR Mini -> 30 dB broadband amplifier -> BU500 seems to be sufficiently linear to transmit FreeDV

    - my computer is absolutely overloaded with the software, so to continue I will need to outsource FreeDV to an external laptop.

    - to enable reception, my LNA will be stabilized with an external, GPS controlled 26 MHz oscillator.

    - if the LimeSDr Mini keeps freezing I will consider abandoning this device and look for another solution.

    By the way: I like the option to transmit waterfall text in the SDR Console. It really helps to announce FreeDV transmissions with the mode used.

    Best 73

    Holger ‚Geri‘, DK8KW