There is a bit of misinformation in that post. Lets tackle the bits one at a time...
Not really. The antenna will radiate signal no matter what radio its fed with. The efficiency with which it radiates that signal depends on the signal's frequency, how well the antenna is installed, and how well its tuned to a particular frequency
Not necessarily. The best antenna will depend on a number of things. A few of those things are the output level and frequency of the radio, which direction(s) you want your signal to go (IE do you want front-to-back signal, roughly balanced output in all directions, or do you want to concentrate your signal in one direction), and type of installation (vehicle [which can be further broken down into type of vehicle, general vehicle construction and layout, etc], building, tower, etc).
Terms such as quarter wave and half wave generally refer to types of antennas and antenna feed-line lengths, or to the distance a signal travels in a given transmission medium during a specified amount of time, NOT to the waveform of a radio's output. The waveform of the signal coming out of a radio generally depends on the type of modulation being used. For a properly-operating CB, the output waveform is an amplitude-modulated waveform consisting of the sin wave of the carrier frequency modulated by the various sin wave components of the human voice (generally limited by the radio's design to a bandwidth of about 300z to 3.5khz).
My best recommendation for solving your current problem, if you can't locate a shop that is able to help you directly, is to experiment with a few different antenna types, and see if any does significantly better than the others over a test period of a week or two. Also, if you can, it might be helpful to post some detailed photos of your antenna installation. We might be able to better advise you.
One other recommendation I can make is to have a 14.5-foot section of coax made up, and run that from your antenna to your SWR meter, and make your SWR check on (or close to) channel 20. That will give you a VERY accurate indication of the actual SWR seen at the antenna feedpoint. The reason for the 14.5 length is this: that lenght is very close to an exact impedenace repeater on channel 20's frequency, meaning that he impedance (match) seen by the SWR meter end will be the exact same impedance seen at the antenna end.
The basic math involved in arriving at 14.5 ft is to take the freespace wavelength of the signal and multiply it by the velocity factor of the coax, then take that result and divide it by two. For this example, ch 20 frequency = 27.205, which equals a free-space wavelength of 36.15 feet. Taking an example velocity factor of .8 (80%), which is roughly what is seen in the average chunk of RG8X cable, the wavelength through the coax is then 28.92 feet, and a half-wave through that coax is then 14.46 feet. In practice, 14' will give basically the same readings as 14.5 on channel 20
Good Radio Shops
Discussion in 'CB Radio Forum' started by homewrecker 641, Apr 25, 2008.
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Well at least i didn't have to answer that one
So much miss information so much CB MYTHBUSTING to do ....
Thanks DTB I agree 99.999% what you said your post is just about what I would have said back to him ..... Too much made up stuff and bad info out for the CBers to pass along ..... -
Going to all that trouble with cutting coax ....
Heck I use my trusty NOISE BRIDGE and my rusty screwdriver ...... and grid dip meter to tune things .....
These young wipper snappers need fancy antenna analizers ...... -
Your a sick puppy
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Why would he mess with $40 CB's
BTW Our shop does ICOM too .... -
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