I have been noticing some irregular shifts in SO-50's downlink frequency the past several days. I noticed it in the past but it's been a while since this occurred. Several others are reporting it as well.
At my AOS today (15:12 UTC, orbit # 62976), SatPC32 had predicted the downlink to be near 436.801 MHz, when in fact I was receiving the bird at 436.793. It proceeded to jump up to 436.795 at my TCA before making it's way down to 436.780 near my LOS.
This seems to be posing some issues for people using full computer control and also those who stick to pre-programmed memory channels to make frequency adjustments during a pass.
Considering this recent frequency instability, I would recommend you manually tune for the strongest downlink frequency. This would help eliminate some issues with stepping on stations engaged in existing QSO's. An alternative would be to try using RIT if you insist on computer control.
The old rule applies -- if you can't hear, don't transmit.
73 Clayton W5PFG