so anyway i finally got around to doing a proper mobile install for my FT-7900 after running it off a mag mount for like two years and i gotta say the difference with a proper antenna mount is night and day. ran the coax through the trunk, got a nice lip mount on the rear hatch, the whole deal.

but now im getting this kind of whine that goes up and down with the engine rpm. its not terrible but its annoying, especially when im trying to hit the local repeater on the way to work. did the power leads straight to the battery with a fuse close to the battery like everyone says to do, so i dont think its a power issue? the coax is the same RG-8X i had before so probably not that either.

has anyone dealt with this before, im wondering if maybe its something with how i routed the power cable too close to something under the hood. or maybe i need a ferrite choke somewhere. its a 2015 honda crv if that helps

classic alternator whine, happens all the time with mobile installs. the fix that works for me is adding a noise filter inline on the power lead, you can get one at pretty much any auto parts store or order one from ham suppliers. also worth trying a ferrite on the coax where it enters the cab. sometimes just moving the power cable away from ignition wires fixes it too — i had mine running parallel to the engine harness in my old truck and got the same exact thing until i rerouted it. definitely check your ground too, a bad ground will cause all kinds of noise issues. short ground wire directly to the chassis near where the radio is sitting, not daisy chained off some other ground point.

oh man ive had this exact thing on my crv, well mine is a 2017 but probably same deal. for me it turned out to be the ground, i thought i had a good chassis ground but apparently the spot i picked had some paint under there i didnt notice. once i sanded down to bare metal it got way quieter. still had a tiny bit of whine so i slapped a cheap inline filter on it and it went away completely. honestly these hondas seem to be a little noisy compared to some other cars ive installed in