so ive been meaning to get into satellite work for a while and last weekend i finally just did it. grabbed my arrow antenna and the ft-818 and went out to the backyard. been tracking passes with gpredict for about a month just to get a feel for the geometry before actually trying to operate.

first couple passes i was just listening, and honestly hearing the linear transponder was way more exciting than i expected. you can really hear the doppler shift if the pass is anywhere near overhead, like the whole downlink just slides down as it goes past zenith. i knew about it theoretically but hearing it in real time is something else.

actually made a contact on the third pass which i was not expecting at all. guy was running a big az-el setup somewhere in the northeast and his signal was rock solid the whole arc. mine was drifting around because i was trying to hand-track and work the split and not drop the antenna all at once. its a lot to manage solo.

main thing i want to ask — how much does the uplink frequency correction matter when youre running low power? i was trying to manually compensate the doppler on the uplink but im not sure if i was doing it right. the 818 doesnt have satellite mode so its all manual. does it matter that much at 2.4w or does the transponder just pull it in?

linear transponders dont pull anything in, its not FM, so yeah the doppler correction on the uplink matters. but honestly at low elevations the rate of change is slow enough that if you just set it close and nudge every 30 seconds or so youre probably fine. the transponder passband on AO-73 is what, 30kHz? so you have a little wiggle room as long as you stay in there.

the real trick when youre hand-tracking solo is to just accept that you wont be perfect and work the high elevation passes when you have more time before the shift gets steep. i did the same thing with an arrow for almost two years before i built a cheap az-el rotator setup and the manual method works, its just tiring. youll get the feel for it after maybe 10-15 passes.

gpredict is great for this, i use it too. one thing that helped me a lot was running gpredict with the doppler correction plugin talking to my radio via rigctld, even on a rig that doesnt have a dedicated sat mode you can get it to at least handle the downlink automatically and then you only have to worry about the uplink manually. cuts the cognitive load in half when youre also trying to point an antenna. might be worth looking into if you have a cable to connect the 818.