Posts by dm4im

    OTOH, if you put it in a box but the cw beacon still whines even after you allowed the downconverter to settle, there might be a problem other than air draft. Can you make a screen video of your sdr software showing the cw beacon so we can see and hear what's going on? Please also list all equipment involved, like dish-size, lnb, receiver.

    As a reference how it should sound (well, I think it should sound like this) , see https://www.<mycall>.de/uncategorized/qo-100-beacon-snr/

    and https://www.<mycall>.de/wp-content/uploads/2021/10/qo-100_beacon-2021-10-04_10.12.54.mp4

    Replace <mycall>.

    BTW, place the box where vibrations are minimal, preferably on a piece of foam. I once operated it on my operator desk and even bumps from your fist on the desk can be heard as small frequency jumps when you listen to the cw beacon.

    Remember, a frequency variation of 10 milliHertz results in a 3.9Hz shift after multiplied by 390. You will hear that. The crystal in the tcxo after all is a mechanical device. It wants to sit still (and flat) for optimal work.

    73, Martin

    The reason is simple: Air draft will have an impact on the frequency any (tc/oc)xo delivers. The comparator circuit senses the gps generated frequency differs from the frequency generated by the xo , so tries to provide the correct control voltage to compensate for this.

    The xo overshoots slightly, the control voltage will be corrected and so on, until the xo frequency is the same as the gps control frequency. This is a slow process and being slow is good, otherwise you'd experience a lot of jitter.

    You can minimize this when you put the board in an enclosure (plus put some foam on the tcxo) . Or use a ocxo which already is some sort of tcxo but with an air tight enclosure and heater built in. But even then i'd not skimp on an enclosure.

    And please remember, the gps only is there for the long term accuracy, while the tcxo is there for the short term stabilty. It takes a while for the system to settle. Hours at least, days for even better accuracy. Air draft will mess this up and the play starts again.

    73, Martin


    this happens when you close all receivers prior to shutting down SC (sdr console). If you shut it down with a receiver in USB mode still running, it will start with the last frequency, mode etc. when you hit the "Start" icon.

    IIRC you can set a checkmark "automatically run the last receiver when SC loads, no need to hit START" somewhere in the guts of SC. BUT if there was no last receiver when you shut down SC, it can't come up with one.

    So maybe you just need to loose the habit of stopping all receivers before leaving SC.

    Does that help?

    73, Martin

    Die Version im Video ist 0.89. Ist die schon irgendwo veröffentlicht?


    P.S. Der cw-skimmer funktioniert jetzt, dafür geht das Cluster im Moment nicht.

    Wenn Firefox schon installiert war, aber nicht der Standardbrowser ist:

    Gehe zu den Einstellungen von Firefox:

    73, Martin

    Edit : Link removed, no newer participants over a longer period

    Please do NOT participate if the program works with no errors but you can not decode data. This is a different cause.

    Please set a green checkmark for the OS you use if hsmodem runs without issues.

    Set a yellow mark if it runs without crash but displays errors

    Set a red mark if it crashes or doesn't run at all.

    You can edit your choices any time.

    Thank you

    I did a quick research on "recvfrom error: 10040" .

    Found: This usually means that the buffer you provided to recvfrom() was smaller than the incoming datagram.

    So maybe a issue the author can fix easily just by providing a bigger buffer .

    I don't think this will crash the program, but data will be lost.

    I think the buffer size is defined in udp.cpp in this section:

     RXCFG rxcfg;
        memcpy((uint8_t *)(&rxcfg), (uint8_t *)param, sizeof(RXCFG));
            int recvlen;
        const int maxUDPpacketsize = 2048;
            char rxbuf[maxUDPpacketsize];
            struct sockaddr_in fromSock;
            fromlen = sizeof(struct sockaddr_in);
            recvlen = recvfrom(*rxcfg.sock, rxbuf, maxUDPpacketsize, 0, (struct sockaddr *)&fromSock, &fromlen);

    So if you have this issue , replace 2048 with, say 4096 , recompile and see if the message is gone

    But I may be completely wrong and maxUDPpacketsize must decrease instead.

    73, Martin

    With Chromium set as default browser , the qo100info.html will work ok when opened from the Filebrowser as well as when clicked on "Open received HTML file" within hsmodem . This also applies to Slimjet as default browser. Maybe a firefox issue?

    73, Martin

    Is there a debug mode we can start to "see" what causes the modem crash? Found nothing in the wiki.

    DM4DS Can you start it from the command line in the Terminal under windows10?

    Edit: Sorry, just noticed that a DOS BOX opens and shows status messages under windows as well.

    Some Observations when running under Linux:

    hsmodem freezes, when i try to open Firefox by clicking on "Open received HTML file".

    Does not freeze when i go to the folder containing the html file, right click and choose Firefox to open. But will not show any data in the browser. Does not even display "Offline" in red.

    Does not show errors in the Terminal in both cases.

    Works normal when i go to the folder containing the html file, right click and choose Chromium or Slimjet (a fork of Firefox) to open. Will show data in the browser. Displays "OFFLINE " in red and will change to "CONNECTED to local HSmodem" in a second or two.

    I will try later to set the default browser to either Chromium or slimjet and click "Open received html file " to see what happens.

    Will report ASAP.

    73, Martin

    EA2ARU Please more info. Is it Windows or Linux?

    The beauty of running this under Linux is: There is no virtual audio cable.

    See the picture , it is gqrx and hsmodem running on a ubuntu ( Lubuntu , that is). The audio device gqrx delivers audio to is the soundcard, the capture device for hsmodem is MONITOR output of the soundcard. 73, Martin

    EA2ARU There is no Trick. Connect the input of your soundcard to IC9700

    ACC1 , Pin 2 (GND) Pin 5 (Signal).

    OR to Speaker out (not recommended, but will work)

    OR to headphone out (not recommended, but will work)

    Goto hsmodem SETUP, set RX to your soundcard input. Tune your IC9700 RX-frequency until you see the constellation like in post #59 . Follow the instructions in post #59.

    Also, carefully read instructions in your manual about the speaker configuration in chapter [EXT-SP MAIN / EXT-SP SUB] if you connect to your speaker output.

    EDIT: Additionally, check the manual provided by Amsat (see next post) if you want to use USB SOUND features for RX and TX with ICOM Transceivers.

    73, Martin

    Umzug der MM-Bake offenbar erfolgreich.

    10489.993,5 = zero beat, Mittenfrequenz = 995

    Narrow Band Transponder Activity: OK

    Wide Band Transponder Activity: OK

    DX-Cluster Messages: OK

    CW Skimmer: Keine Ausgabe.

    Amsat Bulletin Text-Anzeige: OK

    Setup: Win7 32bit, sdr-console, VB-Cable, HSModem, Firefox

    73, Martin

    PA1EJO Set "exclusive mode" for your virtual audio cables first.

    Then always start hsmodem before you start sdr-console. That should do the trick. Works with VB-audio cable here (others say, vb-audio cable doesn't work at all, maybe this is the workaround ).


    Unter Windows findest du die Datei in C:\Benutzer\<benutzername>\oscardata

    Unter Linux in /home/<benutzername>/oscardata

    Öffne die Datei mit einem normalen Editor.

    73, Martin

    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

    It works!


    The skimmer does not display data despite several cq calls. Maybe it is not yet operational.

    Equipment here: Amsat Downconverter -> VHF Downconverter-> RX on 28MHz

    PC running Linux.

    Great Job!

    73, Martin