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[TowerTalk] Quad Element Tuning

To: <>
Subject: [TowerTalk] Quad Element Tuning
From: (
Date: Fri, 7 Sep 2001 10:40:01 -0600
On Fri, 07 Sep 2001  <> writes:
> Hi All,
> I currently am completing construction of my first quad beam 
> antenna.  I am looking for suggestions about how best to tune 

> Q1)  What is a good method to tune each of the five reflectors?  I 
> can  target a fixed frequency off-set from each of drivers (by 
> percentage). > If so, what should the off-set be?? 

        W8JI reports that self resonant elements tuned to the
        LOWEST frequency used make good Quad reflectors.
        You could start with the formula length (1050?/F) and
        tune the reflectors for zero reactance at the bottom of
        each band.  Tune the reflectors FIRST without the DE
        in place.

> I'm not sure how to use the  MFJ259B
> to tune the F/B or Gain(max), if it can at all.  I could use a field
> strength meter but that's subject to error and my neighbors.

        Antenna Analyzers measure impedance and SWR.
        You need a remote transmitter or receiver to measure
        F/B.  Gain is VERY hard to measure accurately.
        Fortunately, Gain bandwidth is quite broad compared
        with F/B so once you achieve your desired F/B, the gain
        should be within 1 dB of max.  Gain and F/B typically do
        NOT peak at the same frequency.    N4KG
> Q2)  Is there a suggested order through the bands to be tuning 
> either  the dir. or ref.? i.e.- 10>20 or 20>10?

        Higher frequency elements are nearly invisible to lower
        frequency elements.  Lower frequency elements are more
        likely to affect the tuning of the higher frequency elements
        so I would start with 20M and work up in freq.   N4KG
> Q3)  And finally, any suggestions about what is a good method to 
> secure
> each of the loop ends to themselves and/or coax?  I'm using the 
> diamond
> configuration that provides for a vertical spreader as an anchor 
> point.

        One of the more interesting mounting schemes I have seen
        uses hose clamps over a rubber? loop with a piece of small
        rubber hose at each corner for the wire to run through.  The
        rubber pieces came from an auto parts store.  I forgot what
        kind of lines were used.   Tom  N4KG

> Thanks for input!
> Paul   (What is your callsign ?)

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