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Re: [TowerTalk] radials for shunt fed tower

To: "Jim Lux" <>,"Rick Bullon" <>, <>
Subject: Re: [TowerTalk] radials for shunt fed tower
From: "Tom Rauch" <>
Reply-to: Tom Rauch <>
Date: Mon, 6 Dec 2004 06:01:42 -0500
List-post: <>
> > the big box stores was about $14 a spool that would make
the radial system
> > cost about $450 dollars!!! and then there is all the
time and work of
> > putting down 100+ radials

Anything more than 50-60 1/4 wl radials is largely a waste
of time and money.

100 radials give an insignificant improvement only when they
are pretty long.

> 1) You could measure your antennas feedpoint impedance
over a wide range of
> frequencies and compare it to a very high quality EM model
that properly
> handles wires in a dielectric (i.e. NEC4 and its ilk).
> speaking, you'd probably spend more time modeling than
laying the wires, and
> if you're buying 3 miles of wire, you can probably get it
cheaper than from
> Home Depot (if nothing else, you don't want insulated
wire, and you probably
> don't need AWG12).  On the other hand, maybe the ground is
frozen right now,
> and you've nothing better to do (or, at least more
interesting) than to run
> models, so the modeling time is essentially free.

....and you have to remember the LEAST accurate place to use
the model is to predict the behavior of wires near earth,
like radials.

Seems almost foolish to me to use something that might be
off by a factor of four to predict something to a few

Even base impedance doesn't tell you the complete story
about loss.

I'd just pull in 40-60 1/4 wl radials maximum or as many as
I could as long as I could and call it a night. All this
planning and worry over something that can't be easily and
accurately  modeled, measured,  or predicted is the real
waste of energy.

73 Tom


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