Hi Guy and Amsat-List!
I'd like to know the answer to this too! I just recently started using twin FT-817ND's and SatPC32 as well, and notice the exact same thing -- audio drifts slightly thorughout the pass, even though I have the dopper correction set pretty close. For me, it only drifts a few hundred Hz at most, but it's still enough that I have to tweak the offset on the uplink. I'm new to SSB sats so not sure as well if there's something I'm doing wrong. I've got the time on the PC clock set within 1 second, and my lat/long within 0.01 degrees.
I'm measuring the drift just roughly based on my own audio coming back over the downlink -- unfortunately as I've called CQ on FO-29 and VO-52 the last few evening's passes (0100-0500 UTC), no one else has been on the sats for a direct QSO! My own audio comes back nice and clear (even out to 5 degrees elevation) so it's not a reception problem, as far as I know.
Any help for those of us new to the satellites would be appreciated!
Thanks,
Dave KB5WIA CM88 Northern California 2xFT817-ND, Elk Log-Periodic, MH-72 Duplexer, Samsung Netbook running SatPC32.
Is anyone else using two Yaesu FT-817 / 857 / 897 rigs with SatPC32? If so, what do you think I am doing wrong and what are your DOPPLER.SQF data lines for AO-7, VO-52, and FO-29 (as well as any other critical settings)?