cb radios

Hi guys can anyone tell me the difference between a center load , top load or a base load CB antenna? What does this do and what would be best on a cabbed tractor?

The "load of a antenna is where the wire is wrapped. All antennas are 102 inches long. To use shorter ones the wire is wrapped in a coil.

Bottom load is the cheap magnetic antenna with the big base at the bottom.

Center load has a large center piece with metal bottom and top.

Top load is usually fiberglass with a wire wrapped around the inner base.

Top load is usually best unless you are running power. They get the load up high above the structure but will only handle a few watts unless you buy the better grades because of the small wire used.

If you have the radio turned up or have a power booster center load is usually best.

I inherited a CB from my dad and I tried using it for several months and finally packed it away. I never could understand anything that came over the radio. It sounded like everyone had a mouth full of marbles. It did have a short attenna that was magnetic that attached to the car trunk. Does anyone think the antenna was the problem?

John, you forgot to 10-4 the guy.

if you don't have clearance problems [trees,etc.] you're better off with a 102" whip...those short antennae always gave me fits trying to get SWR flat.

10-4, need to go 10-33 for a 10-100

With age capacitors dry out and either short together or loose capacitance.
Hence either noise carries through and/or the set"s alignment/tuning wanders from the Center of the carrier wave.

(quoted from post at 21:36:54 05/22/13) Hi guys can anyone tell me the difference between a center load , top load or a base load CB antenna? What does this do and what would be best on a cabbed tractor?

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Most mobile cb antennas are 1/4 wavelength (108"). To make them shorter a 'load' is created by winding wire closely in a section of the length. The load might be at the bottom, center, top, or continuous. The RF current is a sine wave which in a 1/4 wave is stronger at the bottom. In theory a base loaded antenna should not perform as well as a top loaded antenna. In practice the location and body shielding will have a bigger impact on the performance of similar quality antennae. The common antenna needs a ground plane (metal) to properly perform. I know some tractor cabs are made of fiberglass or molded plastic. On those nonmetallic cabs one needs to add a ground plane. Ground plane kits are available from marine supply stores, or you can try using metal tape applied in an X (2 or more strips) with the antenna mounted in the center, where the tapes cross each other. Another option on a nonmetallic surface is a marine CB antenna. If you decide to go with a fiberglass antenna, check out Francis Antennas. They are continuous load, the wire is inside the fiberglass (less damage when you hit something hard like a tree limb), and are available at many truck stops. If a full 1/4 wave stainless steel whip and any shorter (6' or less) loaded antenna are mounted in the same spot, the full length will perform better. A 108" (102" whip with a 6" spring) sticking up from the top of your tractor cab would be noticed though. BTW: ever notice all the loaded antennas on cop cars are base loaded?