hi,
this is one of those questions that hams will discuss forever. search
the list archive (you can probably use the keyword "elevated" to get
previous posts about this pro and con).
here's an interesting statement about elevated ground systems (scroll
down to see it):
http://www.amgroundsystems.com/agsc_index.htm
Now, granted, he's selling his service for installing in-ground
radials and this pertains to medium wave broadcasting but there are
still some points hams can use.
For one thing, he says they need to be elevated 12 or 15 feet.
Actually I think that's low. I'd say they need to be more like 25
feet up to work on 160 for if they are not sufficiently isolated from
the surface, they cease to be "elevated" in the RF sense. 10 feet is
no distance at all when the wavelength is 500 feet -- that's
essentially like laying in the ground.
Another thing I like about ground level radials is length no longer
matters in the sense that the radials are not a tuned part of the
antenna system. Length therefore only matters as far as increasing
returned current is concerned. Of course the downside is that you
need a lot more. Now if you can get your feed point high enough and
you can suspend 4 radials pretty high up there then give the elevated
thing a try. If it tanks you can always go back to plan A and put a
bunch more on the ground.
73
rob / k5uj
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