I'm running a Midland 75-822 handheld with the Cooltech Gatemount setup which includes 18' coax with molded Firering and 4' tunable Firestik firefly antenna. Initial install gave me SWR hitting about 3; wound up sanding paint off of my ground point under the rear tie down loop and dialed in my SWR to a respectable 1.2 on channels 1 & 40. At channel 19, needle didn't move, a solid 1, I was psyched.
Hopped in my car tonight and noticed my SWR was 1.2 on 1, but had creeped up to 1.5 on 40 and I wanted to tweak it. There was a slight drizzle and after I removed the cap on my Firestik and adjusted my tune, I went back into the Jeep and my SWR was 3+ and I couldn't get it to move no matter what I did with the antenna or ground.