so i picked up a used FT-7900R a couple weeks ago and spent most of saturday getting it mounted in my F-150. ran the power leads straight to the battery with an inline fuse like everyone says to do, and i think i did that part right. the radio seems to work fine but im getting a weird buzz in the audio that kind of changes with engine RPM. like when i rev up the engine the pitch of the buzz goes up with it. its not terrible but its annoying enough that i notice it on every QSO.

also the antenna situation is a bit of a mess right now. i just have a mag mount NMO stuck on the roof which is fine for now but i keep reading about doing a proper lip mount or drilling through the roof and honestly im not sure which way to go. the truck is still pretty new so i dont really want to drill if i can avoid it. anyone done a clean install without permanent holes? the mag mount works but i feel like im leaving performance on the table.

oh and one more thing — is there a repeater directory somewhere that works well for road trips? im heading up through the midwest in about three weeks and want to have something useful loaded into the radio before i go.

the buzz you're describing is almost certainly alternator noise, super common with mobile installs. what you want to try first is making sure your ground for the radio is as short as possible and going directly to the chassis, not through some long roundabout path. sometimes people ground at the fuse box and that adds noise. also check if your power leads are running near any ignition wires because that can induce noise too.

if you've already got good short grounds and its still doing it, a ferrite choke on the power leads near the radio sometimes cleans it right up. you can also try an inline noise filter on the power feed, they're only a few bucks on amazon. i had the same issue in my jeep for months before i realized my ground wire was like 18 inches longer than it needed to be, shortened it up and most of the noise went away.

for the antenna the lip mount is honestly a pretty good compromise if you dont want to drill. you lose maybe a little bit vs a proper ground plane mount through the roof but for everyday VHF/UHF work you probably wont notice much difference. the diamond K400 lip mount is what i use on my wife's car and its held up fine for a couple years.

repeaterbook.com is what basically everyone uses for road trips, you can filter by state and it has an app too which is handy when youre actually driving. i usually export a chunk of repeaters for whatever states im passing through into a CSV and load them into the radio the night before. little tedious but worth it.

also seconding the alternator whine thing, had that exact same problem when i first installed mine and it drove me crazy for weeks lol