Can anyone comment on the sensitivity of the WSJT demod to rate in
and rate out error in FSK441 and JT6M modes?
I am trying to use an old laptop P2 300 Win98 for portable operation
and see that the sampling rate in and rate out are not correct. The
rate in is ~ 1.0045 and the rate out 1.00X +/- .002 but is not
stable. I enter values in Options Rate In and Rate out but the Rate
Out is drifting all the time. I can not stay within the +/- .001
that keep the red warning flag off.
My gut feel is that this is not as sensitive a modem as my desktop
machine in that I audibly hear a lot of pings that do not decode
without clicking on the trace. But maybe that is not true?
Is Rate In the normalized RX sample rate of the sound card ADC to
Is Rate Out the normalized TX sample rate of the sound card DAC to
Also I wonder if the sampling rate drift is not the issue, but that
this is really some kind of worse sampling rate jitter that is
averaged before being displayed and that it is introducing a
significant modem impairment. Or maybe I am missing samples entirely?
On a slightly different note is there any issue with using release
5.9.7 on this old machine for just FSK441 and JT6M instead of 4.9.8?
It seems to work ok and the user interface is much nicer.