I unsuccessfully tried to tune my COBRA 75 WX ST CB with a Radio Shack SWR meter. I first placed my antenna on the center of the roof and also tried putting it on the trunk. I kept changing the position and the height, but anytime I got a low SWR reading (about 1.1 or 1.2) I would try to drive the car, and the reading would randomly change. I then found out, even a slight change in position of the coax cable would major changes in SWR reading. Is this normal. Also, I am planning on having a temporary antenna mount, so the coax cables are permanently mounted anywhere. THanks for the help.