so ive been running a lip mount on the rain gutter of my F-250 for a while now with a Comet SBB-5 and its fine i guess but i keep reading that a proper NMO through the roof is way better for the ground plane and SWR. the thing is i really dont want to drill a hole in a 2023 truck, that feels like a point of no return situation.

my current setup has the coax running down the pillar and under the carpet, SWR is around 1.5 on 2m which i know isnt terrible but i feel like theres some room to improve. i mostly do linked repeaters and some 70cm stuff. the lip mount itself feels a little wobbly at highway speeds too, had a couple moments where i thought the whole thing was gonna go.

anyone actually drilled a roof mount on a newer truck and regretted it or was it worth it? also wondering if those mag mount NMO bases are any good as a middle ground or if that defeats the whole purpose

drilled an NMO in my Tacoma about four years ago and never looked back. yeah its a commitment but if you use a good quality mount, seal it properly with self amalgamating tape and maybe a dab of silicone on the inside, you wont have rust issues. the difference in the ground plane is real — i went from a similar SWR situation to basically flat on 2m. the antenna sits rock solid too, no wobble at all even on the highway.

the mag mounts with NMO fittings are ok but the ground plane on a mag mount is never gonna be as consistent, especially on a truck cab where the metal isnt always centered under the antenna. if youre planning to keep this truck for a while just drill it. worst case you can always get a plug for the hole if you sell it.

1.5 on 2m with a lip mount honestly sounds about right in my experience, i had almost exactly that with a similar setup. i ended up going with a trunk lip NMO adapter thing on my car since i couldnt bring myself to drill either. its better than a regular lip mount because the NMO connector itself is cleaner and you can swap antennas fast. not as good as through the roof but its a reasonable middle ground if the drill is a dealbreaker for you.

also worth checking your coax and connectors before assuming the mount is the problem — i chased an SWR issue for weeks and it was just a slightly loose PL-259 the whole time