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Old 05-16-2011, 06:16 AM   #11
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"I've got several extra feet of antenna wire on my car's cb antenna. Is it best to coil it, wad it, spread it around or snip the excess?"

Wad it up. Coiling it acts like a choke and you lose your transmitting output. The length is critical. Take a look here

The Ultimate Guide to 11 Meter CB Antennas


You also absolutely MUST get yourself a SWR meter and tune your antenna!!!!!! This can make all of the difference! You can have a crappy-ass CB radio from Wal Mart and it will work just as well as the top-of-the-line big dollar radio if the antenna is tuned to the specific radio as installed in the vehicle. The main thing is what is the maximum output of the radio.

All you need to get is the SWR meter and a pigtail to put it in-line, tune the antenna so you have close to a 1:1 match (or lower than a 1.50:1 match) with your radio, antenna and antenna feed line all installed as it is in the car.

Also, for CB's the best place for an antenna is in the center of the roof of a metal skin car (Corvettes need not apply) and grounded to the body. you can use a through-the-roof mount (which should ground right there where it goes through the roof) or a mag mount but ground the coax to the body of the car or you will screw it all up. I use an ohm meter to check for a good ground.

Mounting your CB antenna on the bumper will work as well, but it will be somewhat directional depending on where the mass of the "ground plane" (the car) is. If you mount your antenna on the trailer hitch the radiation will be biased to the rear of the car (the metal mass "ground plane" of the car drives the radiation through the antenna).

Nuff for now?

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Old 05-16-2011, 06:22 AM   #12
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By wadding it up I mean make it a rat's nest. You can also spread it around (make a loop around the car) but it depends on how much you have. Just DO NOT coil it up! And do not make a bend tighter than about 3/4 inch.

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Old 05-17-2011, 07:08 PM   #13
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You might want to read through this similar thread on the forum "Radio communication when cell service is down"

(Sorry, I don't know how to make a proper link to it.)

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Old 05-17-2011, 08:19 PM   #14
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Cool, thanks. I'll just undo what I've got bundled and wrap it around a tennis ball randomly so there are no tight bends.

SWR meter should be on its way soon.

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Old 05-18-2011, 05:53 AM   #15
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NO no no no! Wrapping it around a tennis ball will make a choke. You need to literally wad it up in a mess so it doesn't screw you up. What you are tying to avoid is having any parallels in the coax. Randomness is what you are looking for. It sucks because you have to accept a wadded up bunch of coax in your car somewhere, but the benefits in performance in both receiving and transmitting are worth it. One of my old bosses had a Jeep with a CB and he had his excess coax coiled up under the seat, his radio was absolutely worthless transmit or receive for more than 100 yards line-of-sight (no exaggeration). I tuned it up by wadding up his carefully and neatly coiled coax and adjusting the SWR and now he can communicate for a mile or so.

Did you go to the reference site I posted? If not then go there and read up on feed lines.

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Old 05-18-2011, 01:29 PM   #16
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Quote:
Originally Posted by Vikingdad View Post
NO no no no! Wrapping it around a tennis ball will make a choke. You need to literally wad it up in a mess so it doesn't screw you up. What you are tying to avoid is having any parallels in the coax. Randomness is what you are looking for. It sucks because you have to accept a wadded up bunch of coax in your car somewhere, but the benefits in performance in both receiving and transmitting are worth it. One of my old bosses had a Jeep with a CB and he had his excess coax coiled up under the seat, his radio was absolutely worthless transmit or receive for more than 100 yards line-of-sight (no exaggeration). I tuned it up by wadding up his carefully and neatly coiled coax and adjusting the SWR and now he can communicate for a mile or so.

Did you go to the reference site I posted? If not then go there and read up on feed lines.
I was going to use a tennis ball to ensure there were no tight bends but otherwise make it random like a ball of yarn.

I'll go take a look in the other thread.
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