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Re: Topband: Ground Radials & Multi-Element Antennas

To: <topband@contesting.com>
Subject: Re: Topband: Ground Radials & Multi-Element Antennas
From: "K9AY" <k9ay@k9ay.com>
Date: Thu, 5 Nov 2009 08:53:18 -0600
List-post: <topband@contesting.com">mailto:topband@contesting.com>
> Edward Swynar <gswynar@durham.net> wrote:
>> I've seen ground radial lay-out patterns beneath multi-element
>> verticalarrays illustrated in ON4UN's book that have the ground systems 
>> all inter-connected, thus "commonizing" the radial system for all of the 
>> elements in the array...
>
> In absence of some good reason
> to pass an electric current from wire A to wire B,
> I'd rather keep those wires unconnected.
> Sinisa  YT1NT, VE3EA
>

The objective is to avoid overlapping radials, as would be the case in most 
arrays with 1/4-wave radials. Interactions between individual radials can 
create spots where there is current cancellation, reducing their 
effectiveness. I believe W7EL and K3LC have both verified this through 
modeling. The practice of truncating radials and bonding to a common bus was 
developed empirically in the early days of broadcasting, probably documented 
somewhere in the papers of G.H. Brown. (Personally I would defer to this 
early work -- it was very thorough experimental science.)

Bottom line -- Eddy, if your 1/8-wave radials do not overlap, there should 
be no problem.

Gary
K9AY

_______________________________________________
160 meters is a serious band, it should be treated with respect. - TF4M

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