After you get your computer control working, highly recommended for both you and the people you work, you will need to tweak or at least verify your uplink. Most ham gear is pretty good about frequency and stability, but the local oscillator frequencies may not be quite on, and few hams have digital counters which are highly accurate at a GHz or so. If accessible, the LO output can be measured, usually more accurately. Also, the rigs in the satellites drift a small amount.
What I have done is take advantage of times when I was the only one on mode LU or LS by changing the uplink by +/- 5 kHz at minimum usable TX power. Usually one will sound better than the other. So move in that direction 2-3 kHz and repeat, reducing the TX power as needed. You should be able to box the best uplink frequency quickly. Then you can either change the uplink frequency in your control program, or adjust the LO frequency stored in your program. I do the latter. Of course, always be alert for someone else wanting to use the bird.
I have a system roughly equivalent to Drew's and once I get out of the horizon clutter it only takes 5 watts or so for full quieting under most conditions.
Alan WA4SCA