Here is the short version:
1.) radials are the "other half" of your ground-mounted vertical antenna
2.) dirt doesn't make a very good antenna construction material
Jim Brown wrote:
> Certainly a circularly symmetrical radial system is best, but few of us are
> able to realize it. Mine deviates significantly from that ideal, but the
> antenna works well. The best and most readable description I've seen for the
> function of a radial system is by W2DU, as a chapter of his book
> "Reflections." It's on his website. Google on w2du to find it. N6LF has
> written a rather detailed version that's in the Antenna Book, but there are
> typos in the associated graphics that make it difficult to follow.
> The short answer is that the radial system functions as a return for the
> currents and the fields associated with the antenna. The lower the resistance
> of whatever conductors serve this function (including the earth), the closer
> the antenna comes to full theoretical efficiency. The radial system does NOT
> function as a reflector for the signal. The earth at significantly greater
> distance from the antenna serves that function.
> I have seen many references in the literature to the effect that NEC is not
> very good at modeling ground losses and the effect of radial systems. Count
> me among those who 1) consider real measurement of one radial system compared
> to a reference antenna as the only meaningful predictor; 2) consider soil
> conditions at any given location to be an influence on how many radials it
> takes to get there; and 3) consider Tom's advice, and the advice in the
> Antenna Book to be solid as a rock.
> Jim Brown K9YC
> On Sat, 15 Mar 2008 14:23:26 -0400, Robert Carroll wrote:
>> On the other hand if I were
>> only trying to provide a low loss ground return, I might route the radials
>> for convenience in avoid things like a garden, a pool, or some other object.
>> Which view is the correct one?
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