antenna tuning

I've never had problems before tuning my antenna's. However, I'm in a 2018 Freightliner sleeper now and having SWR issues. I bought a Wilson 2000 with a short post. I mounted it on the mirror with the recommended mirror bracket. Had HIGH SWR's and kept cutting the whip. Soon found out I had...

new to this site not very computer savvy. i just installed a dual whip antenna system on a 2006 freightliner Columbia. antenna's were easy to install and didn't have to tune them once installed. started driving today after installing them last night and did a moving check of the swr on the swr...