so ive been licensed for about 3 years now mostly just doing HF and some local 2m stuff but i finally decided to try working through one of the linear transponder satellites, specifically AO-73 since i kept seeing it mentioned. got gpredict set up on my laptop and printed out a pass schedule for this week.

the problem is i can hear... something. like there's definitely signal there during the pass, some SSB voices and what sounds like CW, but when i try to transmit i either cant find myself in the passband or by the time i think i do the pass is basically over. im running a dual band yagi that i'm hand-holding and manually tracking which is probably not helping. also im not sure i have the doppler correction right — gpredict is doing it automatically through hamlib but i dont know if its actually working because i cant really tell if my radio is tuning or not.

is this just a skill thing that takes practice or am i missing something fundamental about how the linear transponder works. i get the concept — uplink on one band downlink on another, inversed passband — but actually operating it in real time feels chaotic. any advice from people who've actually worked these things would be great

yeah it's almost entirely a skill thing honestly, the first few passes are basically just chaos and then it starts to click. the inversed passband trips everyone up at first — if you tune your uplink up, your downlink moves down, so you have to get that muscle memory going before it becomes natural.

the hand-tracking yagi thing is rough but totally doable for low passes, people have worked satellites with a handheld and a rubber duck so dont let that discourage you. the bigger issue for me when i was starting out was not pre-setting my downlink before the pass even started. like you want to find your own signal before the satellite crests the horizon, even if its just on a beacon or noise floor, so you're not scrambling at AOS.

for the doppler — gpredict with hamlib should be handling it but you have to make sure the rig control is actually connected and responding. i had a whole situation where i thought it was working but the com port wasn't configured right and my radio was just sitting there static while gpredict thought it was tuning. check your rig control window in gpredict and see if the frequency display there is actually changing during a pass, that'll tell you if the link is live.

AO-73 is a good choice, passband isn't huge but activity is decent. give it like 5 or 6 passes before you judge whether it's working, the learning curve is steep but short

the inversed passband thing genuinely took me way longer than it should have to internalize so dont feel bad. i kept trying to chase my signal the wrong direction and just chasing myself out of the passband entirely lol

one thing nobody told me that helped a lot — listen for a distinctive voice or CW and just watch where they are in the passband relative to where you're transmitting. if you can hear yourself at all that's the main goal for the first few passes, actual QSOs can come later. also FO-29 has a bit wider passband if you want something slightly more forgiving to practice on, though it's not always active