Dual Antenna Set Up Question

Discussion in 'CB Radio Forum' started by thetez, Jul 17, 2007.

  1. tfisher63

    tfisher63 Light Load Member

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    If you like you could just peel back 9' or so of your coax and peel the shield back and ground that but you'd have to figure out how to make the center conductor stand up.:biggrin_2559:

    Thats exactly right...just dont cut off the braid....use it for your counterpoise.......lol
     
  2. ee_john

    ee_john Bobtail Member

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    Hello,

    Dual antennas provide ever increasing gain towards the front and back as the separation approaches about 9 feet. After that the gain towards the side starts to approach nothing, but only at 18 feet which should be of little concern to any road vehicle.

    Cophasing two or more antennas is used often by radio stations and hams to direct energy in a desired direction.

    In the case of a truck fed with a good cophase coax harness the antennas are perfectly in phase and will concentrate much signal fore and aft. This might be beneficial to talking up and down the road, but it all depends on the situation at hand.

    I think two antennas provide good diversity for those cases when your trailer might be blocking your one antenna.

    I have a web page showing simulation of two antennas at various separations, but don't have enough points to post it. Feel free to ask me for the link via this web site's messaging system. It explains things much better with real antenna simulation results.

    If I were a trucker I would have two antennas. They work and look cool too... at least this 4 wheeler thinks so.

    I hope this help.

    John
     
  3. Twocycle

    Twocycle <strong>Road Apple</strong>

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    Personally, I've run dual and singles. Can't tell one bit of difference. Right now, I run a Wilson 2000 single. Great antenna.
     
  4. ee_john

    ee_john Bobtail Member

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    This is a good point. My simulations show a clear pattern with more energy fore and aft, but only about 6dB difference which is about one S unit on the meter... almost no change at all.

    One or two good antennas at least 5 feet long will serve you well.