CB Radio antenna
I understand a CB radio antenna needs to be grounded. where is a good place to mount as camper is fiberglass?
Forum Discussion
It sounds like people are confusing "grounding" like you do with an electric circuit for personal safety with antenna groundplanes. Two completely different things.
The groundplane for an antenna is more of a reflective surface that changes the antenna's radiation pattern. A metal car body serves as an antenna's groundplane. Full size half-wave antennas don't need groundplanes but on CB frequencies they are 9 feet long.
The groundplane changes the radiation pattern from somewhat spherical (and upward) to a lower, more useful pattern (down on the ground where the other cars are).
Twin antennas like you see on big-trucks are there for two reasons... mostly these days just so they look "right" but the original reason we because they affect each other and change the radiation pattern to be stronger fore-and-aft and weaker to the sides. The idea was that was better for talking up and down the freeway.
I'm simplifying a lot here but that's some of the nuts and bolts of it.
Oh, also an antenna will tend to have a stronger pattern in the direction toward the bulk of the groundplane. If you mount an antenna at the extreme rear of a car, it will be strongest forward.
The groundplane for an antenna is more of a reflective surface that changes the antenna's radiation pattern. A metal car body serves as an antenna's groundplane. Full size half-wave antennas don't need groundplanes but on CB frequencies they are 9 feet long.
The groundplane changes the radiation pattern from somewhat spherical (and upward) to a lower, more useful pattern (down on the ground where the other cars are).
Twin antennas like you see on big-trucks are there for two reasons... mostly these days just so they look "right" but the original reason we because they affect each other and change the radiation pattern to be stronger fore-and-aft and weaker to the sides. The idea was that was better for talking up and down the freeway.
I'm simplifying a lot here but that's some of the nuts and bolts of it.
Oh, also an antenna will tend to have a stronger pattern in the direction toward the bulk of the groundplane. If you mount an antenna at the extreme rear of a car, it will be strongest forward.
