Highspeed Multimedia Modem for QO-100

  • Hi there,

    got it to work on a Xubuntu from 2020 in a virtual machine on my older Linux. It won't compile on the older Linux, because LIBGC is too old. Anyway, just sent some pictures and received them myself.

    Setup: TX: Elecraft K3 in DataMode, 70cm-Transverter, LZ5HP-Transverter.

    RX: Amsat Downconverter -vy old Model- , 2m-Transverter, Kenwood TS-850, USB-Soundcard. Of course this will not be the ultimate setup. Will try to use it on a Raspi4 . With this setup, 6000 8APSK is possible. To me it was important to see how my TX will work in the first place. Now that i know i can transmit, i will refine RX. CU

  • Hi,
    installed 0.72 today but can't get the sound working. using VB_Audio Cable, I have the free single one and the additional a+b installed.

    Hardware is a Pluto with SDR-Console on a Laptop with i7 CPU running win10 64Bit . The Audio cables are working fine with several other programms i.e. JTDX, fldigi, KGSTV, MMSSTV but hsmodem don't like them. I tried several setting like 48K, 44K1 both with 24 and 16 bit but no success always looks like below

    In the Voice Audio TAB looks the same I get the red sign don't madder which Speaker/Headphone/Microphone is selected

    in the "Treminal Window" I see a list of all my connected audio devices including the 3 VB Audio cables but always get output below.

    QO100modem initialised and running

    restart modem requested


    Close RTTY

    Start request for CAP stream:CABLE Output (VB-Audio Virtual Cable)

    Starting CAP stream:CABLE Output (VB-Audio Virtual Cable) [6]

    err:-9997 device:6 PAdev:20 samprate: 44100.000000

    cannot open capture stream for device:<CABLE Output (VB-Audio Virtual Cable)> -9997

    CAP: cannot open device: CABLE Output (VB-Audio Virtual Cable)

    set speedmode:255

    restart modem requested

    Any hint is welcome.



  • Hi Matthias,

    for a test that seems not possible or only for RX but not for TX as the documentation say the free version support only a single cable, but I need at least 2 to connect it to the sdr console.

    Maybe I will try later just after I did an actual full image backup so I can go back if it won't work as expected.



  • Hi Elmar,

    I have been eperienced the same "issue", but in my case, selecting the last check box, to start the transmission and reception of DV (This is in the same page, of parameter show in tour post) , the red cross move to green tick. In my opinion, the app doing the check of audio parameters only when you select a mode to use the digital encoder.

    After this all run well.

    Please try this and tell me if the issue is solved.



  • Hi Alex,
    tested your sugestion but this bring only the Speaker and Microphone in the Voice Audio tab to get a green check but the Tranceiver Audio TX/RX in the setup tab still on red.

    So seems the last option is to try with other virtual audio drivers but this require a deinstalltion of the current one which work fine for me with all other software and as this is windows where I would prefer the way to not touch a running system if not needed ;)

    Such test I would normaly prefer to do on a copy of a VM where it is easy to go back, mybe try that later.



  • Hi folks,

    HSMODEM don´t work in coexistence with Flexradios DAX audiodrivers. That buck is not removed through new version. I tested it on several machines. No chance to get HSModem to work, if you use a Flexradio transceiver and installed the dax drivers for digital modes. If you uninstall and don´t install dax drivers, it works.

    That´s not a solution for me!

    So sorry, I can not use HSModem.

    I have minimum 10 other audio applications, that have no problems with the coexistence of dax drivers.

    If you have the same problem you can not see the spectrum and cloud view.

    The problem is known by the autor but I heard no activity to solve it

    73 de Frank DL2GRF

  • Hi,

    the program can run on two different computers and communicate via network , but the installation is the same on both computers. So if DJ0ABR is willing to split the installation into 2 parts, GUI and modem, the gui could install on a win pc without the drivers side by side with the flex software while the modem part could run on a raspberry pi or on a another windows pc. This may also eliminate the hassle with the virtual audio cables.

    73, Martin

  • Hi!

    I have a problem with ahigh speed modem.

    When starting everything runs normally,but after 3 to 4 seconds the modem

    loses the IP address and gives me an error massages.

    For the transmission of the sound signals I have already testet with virtual VB cables

    and also with VAC cables.

    As soon as I switch on my sound card this state occurs.

    If I deactive all sound assignments, the IP address is also retained in the lover window.

    Can someone give me some advice on what that could be.

  • Hello All,

    Just installed HS Modem , I have a problem when I transmit the output RF signal is not constant it is chopped few seconds ON and few seconds OFF. I have followed the instructions when using a Pluto and SDR Console.

    The HS Modem looks like a very nice tool but I rarely see signals on the transponder , before to invest more time I would prefer to understand why , is the software fully operational ? still suported ?

    Thank you

    73 jacques F6BKI

  • Hi Ernst,

    Go to "SETUP", select the audio device carrying RX audio (VAC in your case).

    Bring the volume up to about the level shown in the picture below.

    Tune your rx to make the signal fill the "Tuning Window", with the leftmost peak centered in the "Ref" column. The circle should show a constellation like in the picture.

    Go to "File", wait for the button " Open received HTML file" to show up. Click on it and have your browser display incomming data.

    73, Martin

  • Will try it, thanks