Ground radials ........ the more the better....... to a point of economics
and dimishing returns. As to the number, 60 will be better than 30 but only
very little is to be gained by going to 120. As to length, no need to make
the copper investments go up. A general length of 1/4 wave does great with
little to be realized from 1/2 wave. And precise length is not really
important either. Just run them out a reasonable distance and let that be
it. If one has to go around a tree or building, then so be it. Just get
the wire in the ground and no more than 6" deep or so. Actually I've found
them best laid in the fall when the grass is dead, cut it real close with
the mower and stretch them out on the surface. I've made up some 6" long
"lawn staples" and just staple them to the earth. Then let mother nature's
freezing and thawing and the new grass of spring cover them up. Also, I've
seen and read about installations where at some distance from the common
point the radials were bonded together in a circular fashion. In short....
DON'T. Current problems will abound. Also it isn't necessary and generally
not suggested to place a driven ground rod at the end of the radials.
Remember we are speaking of surface of the earth not depth.
Here's a good link and article:
http://www.ncjweb.com/k3lcmaxgainradials.pdf
Once that's done and in place then the subject of feeding a tower is another
topic for discussion. My preference is the unipole approach for 160M and
75M.
73
Bob, K4TAX
----- Original Message -----
From: "Mike Gorniak" <gorniak@ncis.com>
To: <tentec@contesting.com>
Sent: Monday, June 07, 2004 9:47 PM
Subject: [TenTec] Radials
> There is no advantage to making ground radials resonant. Resonance
> contributes nothing to the efficiency of the system.
> Those that believe otherwise have not spent any time with a calibrated
> Field Strength Meter. The old rules still apply: More radials are better
> than fewer, and many shorter radials are preferable to fewer longer ones.
>
> The "point of diminishing returns" will vary relative to each person's
> perspective. On 160 meters, 30 (nominally) one quarter wavelength radials
> will yield a field strength at any ground wave reference distance that is
> within 3 db of 120 one quarter wavelength radials.
>
> Mike
> NM7X
>
>
>
>
>
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>
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