CB's and RV's
I am considering having a 102" whip mounted to my Class C rear bumper so I can have a cb in my cab. I missed having one when I was roaming the west this summer in all those remote locations. I plan to...
Forum Discussion
A 102" whip is close to the full quarter-wavelength for CB frequencies, so you probably should achieve a decent SWR.
Try to keep the base mount as high as possible on the body, so most of the whip is above the roof, even if the front tip is held down by a clip while traveling. Any portion of the whip below the roofline will have more of a directional signal pattern, and an omni-directional pattern is the ideal.
The issue with antenna mounting on many RV's is that they never develop a good ground plane.
If you're mounting a loading coil-type antenna (the short kind) on a fiberglass side or roof, you won't have much of a ground plane -- which is what creates the additional antenna length. On those vehicles, an NGP (No Ground Plane) antenna uses a specially designed coax cable to serve as the ground plane, instead of wire radials or connection to a wide metal frame.
For those advocating a metal plate on the roof for the magnet mount, make it as large a square plate as feasible around other roof openings. That plate will serve as the ground plane; for SWR, the bigger plate, the better.
Cheers,
Gerry Stoloff (WA3HDI)
Try to keep the base mount as high as possible on the body, so most of the whip is above the roof, even if the front tip is held down by a clip while traveling. Any portion of the whip below the roofline will have more of a directional signal pattern, and an omni-directional pattern is the ideal.
The issue with antenna mounting on many RV's is that they never develop a good ground plane.
If you're mounting a loading coil-type antenna (the short kind) on a fiberglass side or roof, you won't have much of a ground plane -- which is what creates the additional antenna length. On those vehicles, an NGP (No Ground Plane) antenna uses a specially designed coax cable to serve as the ground plane, instead of wire radials or connection to a wide metal frame.
For those advocating a metal plate on the roof for the magnet mount, make it as large a square plate as feasible around other roof openings. That plate will serve as the ground plane; for SWR, the bigger plate, the better.
Cheers,
Gerry Stoloff (WA3HDI)
