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The Highspeed Multimedia Modem in practice

The Highspeed Multimedia Modem is a system for fast transmission of data in a normal 2.7 kHz voice channel via QO-100. Compared to conventional systems, the transmission speed is increased by a factor of 5 to 10. This modem is suitable for the transmission of images, any files, texts, HTML web files and program files up to complete web presences as well as for digitized speech.

For a station presentation, for example, you can send the image of your QSL card together with cleanly formatted text and the receiver will automatically open the web browser to display the received presentation.

The high-speed modem works full duplex, i.e. transmission and reception run simultaneously. This allows you to check your own transmission, as requested by the satellite operator. A full duplex QSO is possible in split mode (TX and RX frequency offset by e.g. 5 kHz). This allows true intercom in digital speech.

Required equipment

  • QO-100 radio system
  • PC with Windows (Version 10, probably executable from V7, but not tested)
  • PC with Linux (all distributions)
  • Single-board computer, Raspberry Pi 4 and Odroid N2, N2+, C2 and C4 
    (Raspberry Pi 3B+ only with remote network operation)
  • Optional for remote network operation: any PC (Windows, Linux) 
    for the user interface.
en/hsmodem/praxis.txt · Last modified: 2021/03/28 19:14 (external edit)