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Re: Topband: Forestry Effect on Antennas and Radials

To: Charles Moizeau <w2sh@msn.com>
Subject: Re: Topband: Forestry Effect on Antennas and Radials
From: Guy Olinger K2AV <olinger@bellsouth.net>
Date: Sun, 4 Jul 2010 12:37:01 -0400
List-post: <topband@contesting.com">mailto:topband@contesting.com>
Whether forested areas absorb vertically polarized radiation is
controversial, and personally I have not seen anything convincing
either way.

Discounting the trees as an issue,  adding 16 long radials to 22 short
ones would not make a noticeable difference in the middle of a 500
acre lawn.  It is the DENSITY of radials out to the EDGE of the radial
field that makes the most difference.

As to the beverage,  there are many positive anecdotes resulting from
running beverages through the woods, not the least of which is the
advantage of opportunistic support.  Having the beverage mildly
"wiggle" from a straight line to take advantage of tree trunks does
not affect pattern or performance.

Another probably unprovable speculation, is that a forest floor will
remain more damp than say, a lawn, and rotting leaves and needles help
that.  Just one item in the controversy about whether forests help or
hinder.

73, Guy.

On Sat, Jul 3, 2010 at 6:11 PM, Charles Moizeau <w2sh@msn.com> wrote:
>
>
>
> At my QTH in NJ I have the capability to mount a 500-foot,
> two-line, reversible Beverage running NE-SW.
> However, I am hesitant to undertake this project because the antenna
> would be entirely in the woods.  These are not dense woods, for deer now 
> consume every sapling.  Therefore, there are only trees of from 25
> to 90 feet high.
>
>
>
> Because of the deer, the Beverage would have to be at least
> six feet high.
>
>
>
> Two questions:
> 1)  Would the antenna, 500 feet
> long, still be reasonably effective at that height?  2)  Would it be able to
> receive an adequate signal in the described woods?
>
>
>
> For the record, I already notice that 16 in-ground radials,
> each 160 feet long and running entirely in the woods, produced very little
> change in the performance of my vertical transmitting antenna when they were
> added to an existing field of 22 radials, 60-120 feet long, installed in an
> open lawn area.
>
>
>
> I have tentatively concluded that the woods to the north are
> absorbing the radiation from my transmit antenna, and therefore the same kind
> of woods, lying to the south and east but more than 100 feet away, will
> seriously diminish the signal reaching the Beverage.
>
>
>
> I’d greatly welcome reading comments on this list about your
> experiences with the effects of wooded terrain on Beverages and also on
> in-ground radials.
>
>
>
> 73,
>
>
>
> Charles,W2SH
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
>
_______________________________________________
UR RST IS ... ... ..9 QSB QSB - hw? BK

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