WB4KDI Engineering Notebook

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Rig to Computer Interfaces
- K2 Deluxe Serial Port and Data Modes Interface

WSJT Modes are NOT QRP modes!

WSJT modes (FT8, JT65, JT9, etc) are weak signal modes, but not exclusively QRP.

10-25 Watts and a dipole are usually sufficient to work just about anywhere with signal level of -10 or better. More power may be needed to QSO during poor band conditions or to work DX. These modes work well with QRP (5W) and QRPp (<1W) signals. Problems handling strong signals are usually limitations in the receiver and computer sound interface and not because the loud station is running too much power.

WSJT modes require accurate clock time to decode properly.

• Linux
  1. The NEW Way - Use Systemd Timesyncd
     1. Enable and start:

        sudo systemctl enable systemd-timesyncd
        sudo systemctl start systemd-timesyncd

     2. Set custom NTP servers in /etc/systemd/timesyncd.conf.
     3. To see if systemd-timesync.service is running -

        systemctl status systemd-timesyncd
        

  2. The OLD Way - Setup NTP
     1. Modern Linux can keep clock synced to within 100ms.
     2. ntpq -p example output: (offset is in milliseconds)

             remote           refid      st t when poll reach   delay   offset  jitter
        ==============================================================================
        -proxy           173.230.149.23   3 u  359 1024  377    0.168   10.870   3.696
        -fush.slash31.co 216.218.192.202  2 u  684 1024  377   88.406   -0.044   3.145
        *clock.team-cymr 172.16.32.4      2 u  899 1024  377   68.605    7.289   4.315
        +yurizoku.tk     200.98.196.212   2 u  652 1024  377   42.616    0.782   2.607
        -stratum-2-core- 192.168.1.109    2 u  702 1024  377   67.733   29.876   2.396
        +soft-sea-01.ser 216.171.120.36   2 u  793 1024  377  105.007    7.179   3.443
        

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WSJT-X

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