Nobody's laughing at you -- it's a topic that's very poorly understood.

Here's how it works with buried radials. . .

It never hurts to make them longer. But beyond some distance, it doesn't
help appreciably -- if the current on a radial has dropped to a
negligible value at its end, extending it won't do anything.

What is this distance? Well, like so many other things, the only really
honest answer is that it depends. As it turns out, the current fades
more rapidly if you have only a few radials. So if you only have a few,
it doesn't help to make them super long. If you have a lot (say, 60 or
more), increasing the length has more effect -- but your system will
already be so efficient that it won't make much difference.

The classic set of measurements of various ground systems was published
in 1937 as "Ground Systems as a Factor in Antenna Efficiency" by Brown,
Lewis, and Epstein. Their paper has many graphs of the effectiveness of
various combinations of radial lengths and number of radials for various
vertical heights -- for the particular ground at the place of their
experiments, the characteristics of which weren't recorded. Their data
have been interpreted and reorganized countless times and in countless
ways -- a web search should bring you a lot of hits. But some rules of
thumb (and only rules of thumb) for amateurs(*) emerge:

1. There's not much point in making radials much longer than a
free-space quarter wavelength or so.

2. Increasing the number of radials from 16 to 120 or more will probably
net you less than a couple of dB. That might be worth it to you, it
might not.

These assume more-or-less average soil. If your soil is very dry, you
might benefit from more and/or longer radials.

And of course, there's no point in fussing over exact lengths. There's
no need to even make them the same length. Put down what you can and
don't worry about it. Putting in more won't hurt, nor will making them
longer. But you're not likely to notice much difference between a big
installation and a fairly simple one, unless your ground is
extraordinarily poor.

Roy Lewallen, W7EL

(*) An increase in field strength of a few percent is a worthwhile
pursuit for AM broadcasters, because it increases the size of their
audience and hence the value of their advertising. Small increments like
that are completely useless for amateurs, though, so our goals are
somewhat different. Keep that in mind when looking through various
analyses and recommendations, since most are oriented toward broadcasters.


Charlie wrote:
I just want to thank all of you for your kindness and speediness in pointing
out my error as a new vertical antenna user. I am glad several of you had a
laugh on me for burying tuned radials. Thank you for your kindness and
courtesy. Hope to catch each and every one of you on the bands. I am
grateful for the tact and diplomacy that many of you showed me. True Ham
Spirit at it's best.

Based on what I have been told by the gentlemen in this great group I could
have used much shorter radials than any "tuned length". If that is right
then I have achieved a much more effective radial system then what I would
have had I not erred. Is this right? In other words I have more wire in the
ground then I need..right? Now if that is so..does that hurt or help

TY Roy

73 / DX