SWR reading is SUPER high!!! Advise please!

Discussion in 'CB Radio Forum' started by Longshot34, Nov 30, 2011.

  1. TLGken

    TLGken Light Load Member

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    May 18, 2008
    Dallas, TX
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    Try checking the simple things, yes, make sure the annteane and radio is well grounded, Make sure the insulating washer on the actual mount is on the anteana side, and make sure the power is actually getting through the mount!

    good luck!
     
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  3. AB7IF

    AB7IF Light Load Member

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    Jun 11, 2011
    Somewhere, Ar
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    One antenna does not work better than two. This is one of those shade tree CB shop myths lacking in credible evidence gained by proper research. Most often put forth by those CB shop employees unable to make two properly function.

    One antenna merely has more gain in certain directions and less gain in certain others as is seen by the radiation patterns from a phased array when comparing the two. Not to mention if the trailer is blocking one direction you have a weaker signal in those minimum lobe directions as opposed to the signal all around you when running two antennas. If the person you are talking to is in a direction of one of these major axis lobes coming from a phased array then one does not work better it does worse than two. Furthermore since noise comes in from all directions and algebraically sums in the receiver front end, combined with the fact that on the minimum axis of an array noise is reduced you not only have a stronger signal in the direction you are aimed at you also have less overall noise.

    Consider the fact that the microwatts per CM squared of noise meaning the noise coming in from all directions 360 degrees around the antenna sums to a total figure in terms of energy density impinging on the antenna. Compare the total number of microwatts per CM2 if you block the energy along an axis called the minimum lobe for an array. You will arrive at a total noise energy density which is less than the total in 360 degrees. Doing a fast Fourier transform analysis upon all of the energy within the bandwidth of the receiver you will see that the array is quite simply quieter than the simple vertical. Anyone running a beam knows this from experience.

    Your statement 'one is better than two' is without either merit or foundation based upon the mathematics of RF engineering.

    Let me guess next you will have us believe 'one robs half the power from the other' another in the long line of myth's I hear from people who tell me 'the last CB shop told me that'.

    As you are the one making the statement one works better than two kindly show here with proper scientific foundation the proof of your concept. Include your sources and references from various universities and yes I will also accept treatises written up in ARRL handbooks.

    On the topic of SWR here is something to read which I wrote back in the 80's.

    http://www.cbtricks.com/members/ab7if/coax/coax.htm

    If you backspace out coax/coax.htm to get to the index page there are a few other writings which may be of use to some.
     
    Last edited: Dec 5, 2011
  4. mike5511

    mike5511 Road Train Member

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    May 15, 2011
    NW Arkansas
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    Well that went right over the top of my bald head!!!:biggrin_2559: (for the most part) You tech types on here just carry on without me! (I realize by making that comment I've set myself up for some zingers! Well bring it on if you feel the need, I can take it!:biggrin_25522:)
     
  5. kd5drx

    kd5drx <strong>Master of Electronic Communications</stron

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    Nov 28, 2006
    Some where USA
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    WOW your theory is sound and is with out a doubt good but you just went 200 feet down a well in a 10 foot wading pond. 90% of the readers here have no idea what you said. I know you mean well and i understand your trying to get them to think for them selves and do some research and not listen to these truck stop wizards with a screwdriver and a watt meter. But some times we have to speak to your audience in a language they can understand.
     
  6. AB7IF

    AB7IF Light Load Member

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    Jun 11, 2011
    Somewhere, Ar
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    Actually I was since in talking authoritatively he is purporting himself to be a technician. How could a mere layperson make such a matter of fact statement to dispute another when they stated unequivocally 'one antenna is better than two'? The thing that really bothers me is I just saw in your quote I left an r out of array. Fixed it.
     
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