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Antanna & wire length

Discussion in 'Communication (CB | GPS | HAM)' started by K5Kell, Feb 18, 2003.

  1. K5Kell

    K5Kell Guest

    I just found an old cb and 8 ft antanna laying around so I may as well stick em in but a friend told me that a certain amount of antanna wire is required for every foot of antanna. is this true /forums/images/graemlins/confused.gif? if so what is the ratio? any help would be great /forums/images/graemlins/thumb.gif!
    -Kell-
     
  2. Z3PR

    Z3PR Banned

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    Lot of people belive that you need 18 foot of coax. I personally have used how ever much coax I needed. I've never found a preformance loss by useing more then, or less then 18 feet.
     
  3. Judd

    Judd 1/2 ton status

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    ZP3R has just told you the truth. /forums/images/graemlins/thumb.gif There is a old CBr's tale that you have to have so many feet of coax{18 feet sounds about right/ 1/4 of a wave-whatever}. Then you have to have this magical amount between the radio and amp,ect, ect, ect. It ain't so, the shorter the better with-in reason. Go to a few Ham sites and ask them. They like having /forums/images/graemlins/ears.gifs, if it helped they would do it.
     
  4. rebelk5frk

    rebelk5frk 1/2 ton status

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    just like the other 2 guys said. Use however much coax you need to reach between the antenna and radio. As short and the lengths are going to be any extra coax won't really hurt anything but why pay for coax you don't need.
     
  5. Sandman

    Sandman 3/4 ton status Author

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    If you really wanted to be fickle, You can change the capacitance and the inductance levels of the wire by how long you cut it. There is a formula and a chart depending on what wire you use. If you do it right, You can cut it so that you have a 52 ohm load with no capacitance or inductance at all. The CB wire that allready has the ends on it are setup this way. It does not matter as much in the lower frequencies like the CB band. Makes a big difference up towards a gig though.
     

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