JS8 Digimode Trial?

  • Hello Digimode Users!

    I'd like to conduct a trial of the FT8 derivate mode JS8 via QO-100.

    JS8 is a low power, low bandwidth "ragchew" mode based on the well-known FT8 modulation scheme of WSJT-X. Instead of a rather fix and pre-formatted minimalistic QSO style, one can exchange messages of free content, including information like your names, QTH, rig and weather info or whatever you like. Imagine it like an RTTY or PSK machine with enhanced demodulation and operation capabilities.

    Beside the more human kind of conversation possible with the JS8 mode, it has the advantage of so-called "heartbeats". They are a kind of beacons showing you are qrv and willing to qso. These heartbeats can automatically be acknowledged by those listening. And JS8 offers depending on SNR and propagation four different speeds from 8 to 40 wpm in time slots of 30 s down to 6 s with bandwidths between 25 and 160 Hz.

    JS8 is handled with the free program JS8Call by KN4CRD and it's available for the following platforms:

    Windows 10 (seems to work down to XP)

    Mac OSX 10.11+ (x86_64)

    Desktop Linux (deb)

    Raspbian (RaspberryPi, armv7, deb)


    Like with the NB-Digimodes on HF a coordinated frequency is very helpful to get in contact. As there is no recommendation for JS8 on QO-100 yet, I suggest 10489.548 MHz (Uplink 2400.048 MHz) USB in the NB Digi section of the bandplan as many HF frequencies for JS8 are ending with an 8.

    So, if you are already familiar with FT8 and WSJT-X and you like to know more than grid locator and signal report about and from your QSO partners, then give JS8Call a try. I'll be listening the next days and weeks on 10489.548 MHz, whenever family and QRL are giving the time.

    73 es cu


  • Hello!
    I'm glad to see some interest in conducting a new attempt of JS8CALL on QO-100. What about using the monthly JS8 QSO Party as the next date?
    It'll be from Saturday, November 13 th 19:00 UTC until Sunday 14th 19:00 UTC. Probably it could be helpful to limit the activity time on QO-100 to a shorter period to increase the probability of finding each other.
    So hw?

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  • Hi friends,

    I must apologize for not being there yesterday. During the first test my PC crashed with a faulty JS8call process after aview minutes of listening. And I didn't get the system running anymore yesterday evening. I'm so sorry and hope we can conduct the next test session for the next JS8 QSO party.

    73, cu

    Frank DL6DBN