[TowerTalk] Ground Radial Fields

[Guy Olinger, K2AV]

On Tue, 30 Mar 1999 13:36:23 +0100, you wrote:

>
>Hi Tom, Thanks for the I/P yes N6RK has interesting info on his web page
>about the work he did measuring radial field differences all very
>interesting stuff. It can be found at <http://www.karlquist.com> . 73 Clive
>GM3POI
>
>-----Original Message-----
>From: Tom Rauch <w8ji@contesting.com>
>To: TowerTalk <towertalk@contesting.com>; Clive Penna
><clive@gm3poi.prestel.co.uk>
>Date: 30 March 1999 12:48
>Subject: Re: [TowerTalk] Ground Radial Fields
>
>
>
>
>> HI, Does anyone have any field strength data, re the lowering
>> of radiation angle in a given direction if extra radials are concentrated
>> in that direction. ie taken to the extreme 60 radials covering 180deg
>> whether that arrangement would have the performance of 120 radials at the
>> mid way point,and the radiation angle increasing as you run out of
>> radials. 73 Clive GM3POI
>
>You might ask on rec.radio.amateur.antenna I think it is N6RK who
>actually measured this stuff, and his measurenents agree with
>theory.
>
>Theory tells us the radials do nothing at all for low wave angle
>performance unless they are several wavelengths long and very
>desnse (about .05 wl spacing) at the open ends.
>
>Also, if you concentrate radials in one hemisphere efficiency in
>EVERY direction drops.

Is it possible that on N6RK's figures, that his comparisons were
invalidated for a setup using equal radials over 360 degrees, simply
because he did not run them in all directions? 

This also leaves one with the enormous problem of huge real estate and
a fortune in wire to validate.

I also would appreciate some comment as to whether 20m results
properly extrapolate to say, 160m. I'm not planning to use a vertical
on 20m, though I understand why he used 20m.

>
>I found that true at WAAM radio, where someone cut and removed
>all radials going in the direction of a desired null. The only result of
>that was a decrease in field strength in all directions and instability
>of the array with soil moisture changes.
>
>73, Tom W8JI
>w8ji@contesting.com
>
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73, Guy
--. .-..

Guy Olinger, K2AV
k2av@qsl.net
Apex, NC, USA


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