so ive been trying to work AO-73 for a few weeks now and i just cannot get a solid contact. i know the transponder is inverting so i have my radio set up for that, USB on uplink and LSB on downlink or whatever the correct combo is, but every time i think im hearing myself in the passband the signal just drifts all over the place before i can tune it out.

im using a yaesu ft-818 with a pair of handheld yagis, az/el is manual which i know is part of the problem but ive tracked the bird visually before so i dont think its a pointing issue. doppler correction is where im getting confused though. like i understand conceptually that i need to tune as the satellite gets closer vs moving away but doing it in real time while also trying to hold the antennas and key the mic is basically impossible solo.

is there some trick to this that im missing or do i really need to go full rotator + computer setup before this is ever gonna work? i see people making contacts with handheld yagis all the time on youtube so it must be possible

the doppler thing on a linear transponder is what gets everyone at first. the key thing people dont realize is you mostly correct on the downlink, not the uplink. find your own signal in the passband and then just keep retuning your receive frequency to keep it where it sounds right - your transmitted signal will naturally land in the right spot. if you chase doppler on both ends simultaneously by yourself it becomes a nightmare real fast.

for solo handheld operation i actually tuck one antenna under my arm against my body during passes to free up a hand, it sounds dumb but it works well enough for the low elevation parts of a pass. the real trick though is just doing a lot of passes and getting the muscle memory down. also worth checking if your ft-818 has the satellite mode enabled, it handles some of that vfo splitting automatically which helps a lot with the inverting transponder situation.

yeah this took me forever to figure out too. one thing that helped me before i had a rotator was just picking passes that go close to overhead - like 70+ degrees max elevation - because you get more time near the peak where doppler rate is slowest and you can actually breathe for a second. the low horizon passes are brutal to work handheld because the doppler is changing fast AND the signal is weaker so youre fighting everything at once.

also gpredict is free and if you run it on a laptop next to you it at least tells you what frequency you should theoretically be on even if you cant automate it. i had it open on my phone for a while just as a reference. not perfect but better than nothing