[Elecraft] K3S and FT8

Wes Stewart wes_n7ws at triconet.org
Mon Jul 31 15:19:21 EDT 2017


I've made a few QSOs with FT8 but have had less then stellar success.  In 
looking for possibly causes I took a close look at timing, since a lot of the 
chatter in the WSJT Yahoo group is about the need for close time synchronization.

I noted that when my transmit interval occurred, there seemed to be about a one 
and a half second delay before the K3 began to transmit. I began an exchange of 
email with Bill, G4WJS, about this issue.  I quote from one of his:

    "If you are seeing a 1.5s delay then that is because CAT commands sent
    before PTT, even if PTT is "virtual" due to using VOX, are taking
    roughly that long. The K3 series is problematic in that certain CAT
    commands can take a long time to complete, these are mostly mode change
    related, even if the mode does not actually change, as a DSP reset that
    takes 0.5s or so has to be completed before the CAT command returns
    success. I suggest setting "Settings->Radio->Mode" to "None" and setting
    the rig to USB-DATA-A sub-mode manually on both VFOs, as a test to see
    if things speed up for you."

I tried his suggestion and didn't see much change, then I decided to turn off 
Split in the program.  This reduced the apparent delay to <0.5 second. I say 
apparent because these are eyeball measurements, best made by looking at the 
clock display while listening for the TX audio to drop out.  The message is 12.6 
seconds long so if it ends at or around 13 seconds I would guess good enough.

Anyone else see any of this?

Wes, N7WS



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