swr question

Discussion in 'CB Radio Forum' started by tony7914, Apr 9, 2011.

  1. WA4GCH

    WA4GCH Road Train Member

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  2. Rat

    Rat Road Train Member

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  3. WA4GCH

    WA4GCH Road Train Member

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  4. handlebar

    handlebar Heavy Load Member

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    Not really. Besides being petty, it also ignores that SWR is frequency dependent. Since many CB antennas are fairly narrowbanded because of the methods used to physically shorten them, CBrs and installers are taught to measure SWR at Ch 1, Ch 20, and Ch 40.

    If they're also running 10 Meters on them (like I do; I'm an Extra), there will be more datum points on the graph.

    I'm at least as much a purist as the next long-experienced RF tech (although I R not a engunnear), and I check *all* the SWRs before I figure an install or repair is complete. Then I can be confident that the "average SWR" over the intended operating range is acceptable.

    But I do it by getting several SWRs.

    However, I sign 73 verbally and in writing, so as not to be perceived as saying, "Best regardses".

    73,
    -- Handlebar --
     
  5. Mad Dog 20/20

    Mad Dog 20/20 Heavy Load Member

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    I love hearing the term "73's" almost as much as hearing about a "set of beams" when referring to one directional antenna.:biggrin_2559::biggrin_25522:
     
  6. Gadfly

    Gadfly Medium Load Member

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    Well I was just trying to provide one explanation that would make sense to the layman. Yes, the antenna itself is going to present the SAME 'tuning' no matter what. But when you take into consideration variations in power, the various measuring instruments that can give varied reading, etc., you might get a change in apparent SWR. Everybody isn't going to be able to grasp impedances, all the "stuff" that goes along with it. Most of us are simple users of radio and don't need to worry too much about ALL the mechanics. It was just a simple layman's way of explaining why variations in SWR can happen. Not trying to evoke a class in antenna theory.

    GF