ok so ive been listening to AO-7 and SO-50 for a while just to get a feel for things and finally decided to try actually working through a linear transponder sat last week. been using AO-73 mostly because the passes are decent from my location in the midwest and the transponder seems pretty active when its in sunlight.

my setup is an FT-818 and a pair of arrows, doing the handheld thing while tracking with my phone running Heavens-Above and gpredict on the laptop. the problem is i can hear myself in the passband but my signal sounds like trash - drifty and kind of watery i guess? and i know about doppler but i dont think thats the whole issue here. ive been manually tuning both VFOs trying to keep up but it feels like im chasing my tail the whole pass.

also not really sure where to transmit in the passband. i know you want to avoid the edges and stay away from the center beacon but beyond that im kind of guessing. anyone else go through this learning curve or did it click for you pretty fast

the watery sound is almost certainly doppler correction - or rather not correcting fast enough. on a LEO pass with a linear bird you really need to be adjusting constantly, like every few seconds near AOS and LOS especially. the rate of change hits something like plus or minus 10 kHz total shift on 70cm across a full pass and if you're just nudging it every 30 seconds you're gonna sound wobbly to everyone else even if it sounds ok to you locally.

gpredict can actually drive a rig directly if you have CAT set up, that changes everything honestly. once i got that going i just had to focus on not stomping on people rather than constantly twiddling the dial. for passband placement i usually find a clear spot somewhere in the lower third and just stick there, call a couple times, listen. the center gets crowded and the beacon tells you where you are relative to the passband edges anyway so use that as your reference. give it a few more passes, it does click eventually but the first handful are pretty disorienting

yeah i went through exactly this about a year ago. the thing that helped me most was actually slowing down and just listening for a full pass before trying to transmit again. you can learn a lot about where people are operating and how theyre managing doppler just from watching where signals are drifting. also make sure your uplink and downlink are set up as two separate VFOs and that youre tuning the downlink to keep yourself in place - not the uplink. i got that backwards for embarrassingly long lol