Posts by DG2YK

    I'm currently running some full duplex tests with this setting:

    4410 QPSK BW: 2500 Hz (QO-100 standard)

    The bandwidth is slightly lower than the permitted 2.7 KHz, so that images can be received even with imperfect settings.

    I increased the 100 Hz tone slightly using the transmitter's bass settings. This makes the synchronization of the receiver path work easier.

    Best regards


    Merry Christmas.

    A lot of time has passed since my last post, but now I am QRV.

    So far I have transferred images with KG-STV via the is0grb Websdr, see images.

    Transferring Christmas greetings via the waterfall also works very well.

    Now I can work on the HS modem.

    Kind regards from Gescher,

    Wilhelm DG2YK

    Hello Frank,

    thank you for the information. If it shows up again I'll record and test it.

    I played around with the Picfall program a bit.

    It converts images into sound files. My suggestion would be that everyone submits such a file several times like a CQ call. Then there is enough time to start the appropriate program and to set the frequency.

    Best regards,


    Hello Frank,

    thanks for the informations.

    I didn't know VARA-SAT and Winlink-Mailbox yet. I have to take a closer look at that.

    For 1) I found a better screenshot from January 9th.

    Many greetings



    My name is Wilhelm and I am 70 years old. I got my ham radio license as a young man in the 1970th. At that time I had made some experiments using the orbiting Oscar satellites. Image transmission, programming and image processing in different areas of the electro-magnetic spectrum have been my hobbies since that time. Now I would like to start operation via QO-100. On the receiving side I'm already a bit QRV, with a dish in the attic.

    Particularly the HS modem is very interesting. It's a reason for me to get active again via satellite. Many thanks to Kurt for programming it and to everyone who keeps the MultiMedia beacon running.

    However I have problems recognizing some modes. I can distinguish Fax, RTTY, SSTV and KG-STV. But there are some formats on the QO-100 that I can't decode. For example 5) often calls but never gets an answer. My suggestion is that we announce the mode and the baud rate in the waterfall before the broadcast starts, see as an example 3) and 4) in the appendix. A call sign would of course also suffice. Then interested people can google it. A voice announcement only works if one already is listening on the right frequency. In the waterfall, the information would be independent of the correct frequency and, in limits, also of the time.

    What do you think?

    Does anyone know what modes 1), 2), 3) and 5) are?

    I have a further suggestion: The HS modem mutes the sound under Windows11 and it works with a virtual sound cable only. I don't need the cable for the other programs: they work with Windows's internal sound mixer and the sound remains. Maybe that can still be changed.

    Thanks again everyone for the great project,

    have a nice day,

    best regards