so i've been doing FM sats for about a year now and finally decided to jump into the linear transponder stuff. picked up AO-73 last weekend during a decent pass and actually made a contact which i was pretty stoked about, but i have some questions because im still confused about a few things.

first off the doppler correction — i was using gpredict and it was shifting my uplink and downlink frequencies automatically but i couldn't tell if it was doing both correctly. like the downlink seemed fine but i kept hearing my own signal drifting around. is that normal or am i supposed to manually tune one of them while letting the software handle the other? i've seen people say you should tune the downlink by ear and let gpredict handle the uplink but that seems backwards to me

also my signal was way too strong at the start of the pass, i could hear myself crushing other stations. backed off the power but then i couldn't hear myself at all. what's a reasonable starting point power-wise for a handheld yagi setup, i'm running maybe 5 watts into a cheap arrow antenna

yeah the doppler thing on linear sats trips everyone up at first. what you want to do is tune your downlink by ear to keep your signal where it should be, and let gpredict handle the uplink correction. the reason is your ears are faster than any software update loop for finding yourself in the passband. gpredict's rig control is good but there's always a little lag.

5 watts into an arrow is actually plenty, honestly sometimes too much depending on the elevation. the sats with linear transponders are designed to be self-regulating in a sense — if everyone cranks power the transponder just gets saturated and everybody loses. so yeah less is more. i usually start around 2-3 watts and only go up if i really can't hear my downlink, and even then i'm suspicious it's a pointing issue not a power issue. the arrow is pretty directional so small movements matter a lot especially at low elevations.

the hearing yourself drift thing is pretty much just doppler doing its thing, at least early in the pass. AO-73 moves fast enough that you'll notice the shift pretty clearly. i had the same confusion when i started on it coming from FM birds where you just set and forget.

one thing that helped me was running gpredict with CAT control to my radio but then still keeping my hand on the VFO knob for fine tuning the downlink. kind of a hybrid approach. feels clunky at first but you get used to it. the main thing is just keeping yourself in the linear portion of the passband and not stomping on other qsos, the passband is pretty narrow on these things