This forum is dedicated to helping people with questions about installing radio equipment in vehicles. This can include antenna installs, electrical wiring questions/problems, and mounting systems. Pictures of installs are welcome.
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I know it's a little off topic but was hoping someone might offer their opinion.
I have a UHF and a VHF antenna mounted on the cab roof of my pick-up. I used to have a roll bar with a CB antenna mounted to it and it performed excellent with a low SWR of 1.5:1...... I got rid of the roll bar and bought a fiberglass cap for the bed and mounted the CB antenna in the center of the cap. I have a 3 ft X 2 ft of flat sheet metal mounted to the underside of the truck cap to act as a ground plane for a Wilson 1000 antenna (the same one I had on the roll bar) and my SWR readings are above 3 on all channels, which makes me think I don't have enough ground plane.
I have 18 ft of RG 8X cable and have checked that I have no shorts in the cable or mount. I have continuity from the antenna ground to the sheet metal and I grounded the sheet metal to the chassis of the truck...
I'm no expert but is there any way I can bring my SWR down without having to get more sheet metal??
Last edited by Larry on Fri Jun 17, 2005 1:45 pm, edited 2 times in total.
I would have thought you would have used a circular piece of metal in a 3 foot diameter and also grounded the metal to chassis also in insure a good ground.
M1225 UHF VHF, GP300VHF, P1225 UHF, MTS2000(800) with convertacom KI4QMI
Ideally your counterpoise wires should be 1/4 wave on the lowest frequency. That means 9' for CB. The more wires the better but whatever you can reasonably manage will have to do.
Would copper or aluminum foil tape work for this application of creating a ground plane on the underside of a fibergalss truck cap? If so, would 1/2" be wide enough, or should I try to fine something wider?
