so i've been putting this off for like two years but i finally got my FT-857D installed in my F-150 and i gotta say it looks pretty clean if i do say so myself. ran the power leads direct to the battery with an inline fuse, used some split loom to clean up the wiring, and the radio sits in a RAM mount between the seats where i can reach it without taking my eyes off the road too long.

the problem is there's this whine that changes pitch with the engine RPM. it's not super loud but it's definitely there and it's annoying on 2m especially. ive heard of this before, alternator whine right? i put a ferrite choke on the audio line already and it helped a tiny bit but didnt go away. wondering if anyone has dealt with this and what actually fixed it. i dont want to go down a rabbit hole buying a bunch of stuff that doesnt work.

antenna is a Larsen NMO on the roof center if that matters. ground for the antenna goes to the mount which i grounded to the roof skin. maybe thats the issue?

classic alternator whine, yeah. first thing i'd check is whether your negative lead from the radio is going all the way back to the battery and not just to a body ground somewhere. a lot of guys take a shortcut and ground to the nearest bolt and that introduces all kinds of noise paths. the current has to go somewhere and if the negative isn't a clean direct path back to the battery you get all kinds of fun.

also check that your power leads aren't running parallel to any factory wiring for a long distance, especially anything related to the ignition system. i had a similar setup in my old Silverado and re-routing the power cable away from the factory harness made a huge difference. if you've done all that and it's still there, a noise filter on the power line itself (not just the audio) like a cheap Icom or similar inline DC filter can clean things up. some guys swear by them some dont but i've had good luck. the antenna ground thing is probably fine for receive but worth double checking the connection is actually making good metal to metal contact and not just touching paint.

i had this exact thing happen when i did my 2m/70cm mobile setup last spring. turned out my negative wire was like 18 gauge which was just not enough for the current draw and it was picking up all kinds of garbage. went to 12 gauge all the way to the battery negative terminal and it was night and day. might not be your issue but worth checking what gauge you used for the negative side, a lot of kits and guides kind of skimp on that detail.