[TowerTalk] Laying out radials around a stone fence
jim.thom at telus.net
Mon May 14 12:20:08 EDT 2018
Date: Mon, 14 May 2018 10:00:10 -0500
From: Kelly Taylor <ve4xt at mymts.net>
To: Les Kalmus <w2lk at bk-lk.com>
Cc: towertalk at contesting.com
Subject: Re: [TowerTalk] Laying out radials around a stone fence
Sent from my iPhone
> On May 14, 2018, at 08:50, Les Kalmus <w2lk at bk-lk.com> wrote:
> Radials on/in the ground aren't resonant. Most of the current in them will be close to the tower regardless of the length of those radials so put down as many as you can at whatever length they come out which will be better than no radials.
> Les W2LK
>Yes, however the engineering on radials has progressed past asking whether on- or in-ground radials are resonant and now considers the benefits of reducing resisitivity of the soil, as Jim Lux so aptly described. It?s not just about being part of a return path.
>The axiom about more short radials being better than fewer long radials remains, especially if your space or wire supply is limited. But if you have more of each, radials farther out are still beneficial.
>It?s probably still wise to not sacrifice a dense field of radials near the antenna at the altar of fewer longer radials, but it didn?t seem space or wire was limited, merely that there?s an obstacle in the way.
>73, kelly, ve4xt
## AM broadcast stations around here all use 120 radials..and all are at least .4 wave long. Thats a min of four tenths of a wavelength. At .4 wave long, the distance between the far ends of any
2 adjacent radials is optimized. In ON4UNs low band book, he depicts the bulk of the ground reflection occuring .25 wave lengths out from the base of the vertical. If thats the case, then I can see
why you would want them a little longer. If I had a rock wall in the way, I think I would be inclined to go over top of it...or stop at the wall, then continue on the other side. But that would all depend
on how close the wall was to the base of the vertical.
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