[TowerTalk] 10M phased verticals
Ian White GM3SEK
gm3sek at ifwtech.co.uk
Tue Nov 29 12:29:59 PST 2011
Rick Karlquist wrote:
>You ask "is it worth it to make a 4 square array of 5/8 wave
>verticals?"
>
>First we need to determine if it is POSSIBLE to do that.
>I've never seen a published example of that, and my gut
>feel tells me it isn't practical. 4 square
>arrays use 1/4 wave verticals. You can extend the analogy
>to 1/2 wave vertical dipoles fed in their centers with baluns.
>But I don't see how 5/8 wave verticals fed at the bottom
>would work that way, and it isn't clear what the optimum
>spacing should be.
>
>Rick N6RK
W7EL concluded that arrays of base-fed 1/2 or 5/8 wave verticals do not
work as expected, because the presence of the other elements distorts
the current distribution. The effect is small for 1/4-wave verticals,
but arrays of extended elements will require quite different phasing
and/or spacing to obtain good directivity.
<http://eznec.com/Amateur/Articles/Current_Dist.pdf>
--
73 from Ian GM3SEK
http://www.ifwtech.co.uk/g3sek
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