CB antenna tuning

Just spent a couple of hours tinkering with my new two foot FireStik tunable antenna. I already have a four foot that I use offroad, but wanted to keep a shorter antenna on for chatting with any of the SoCalFJCruiser forum guys in the SoCal OC area. The four foot is a pain as it continually ends up hitting everything. When I tuned the four foot using my old RadioShack SWF meter, I had 0.9 on channels 1 and 40 – a really good connection – so expected it to be a bit less efficient with the two foot. However, the first hour of testing resulted in a best SWF of around three – too high to be safe for using it. Couldn't work it out – I knew that there wasn't a great length of antenna protruding above the truck, but I also knew that there was adequate grounding etc. as the other antenna was good. In the end, as I was taking the shorty on and off I realized that the chrome plating on the base of the quick link was starting to chip off – had a quick go at it with my trusty Kershaw Tanto and then retried – SWF of 1.2 on both channels. Looks like the quick link chrome plating isn't doing a great job of conducting! Anyways – all good now after a frustrating couple of hours! It still just clips my garage door as I exit, but at least it leaves it on the runners, unlike the four foot!