so I finally got around to putting my FT-7900R in the truck, been sitting in the box for like 4 months because I kept putting it off. got it mounted under the dash on the passenger side, ran the power cable straight to the battery with a fuse inline, and the radio seems happy. the antenna is a NMO mount that I stuck on the roof right above the rear passenger door, kind of off center because I was worried about drilling through the middle of the roof and hitting something I shouldnt.

it works, I mean I can hit the local repeaters just fine and everyone says my audio sounds okay, but I keep reading that center of the roof is the ideal placement for ground plane and radiation pattern. is my slightly off-center mount going to cause any real world problems or is this one of those things that matters more in theory than actual use? I drive around pretty hilly terrain if that matters at all.

honestly for hitting local repeaters youre probably not gonna notice any difference at all. the off-center thing matters more if youre trying to do something like weak signal work or you care about the pattern being perfectly symmetrical in every direction, which most mobile operators just dont need. ive had mounts all over the place on different vehicles over the years and the real world difference on VHF FM to a repeater is pretty minimal as long as you have decent ground plane under the mount and your coax run isnt a disaster.

the one thing id double check is how you did the NMO mount itself, make sure the coax connection underneath isnt exposed to water getting in around the seal. that can sneak up on you and cause weird intermittent issues months later. other than that sounds like a solid first install to me.

same boat as you when I did my first install, spent way too long reading about perfect roof center placement and then just picked a spot that was easy to drill. been using it for two years no complaints. the repeaters dont care lol