[Top] [All Lists]

Re: [TowerTalk] Vertical in the swamp

To: "" <>
Subject: Re: [TowerTalk] Vertical in the swamp
From: "Jim Brown" <>
Date: Mon, 12 May 2008 23:43:52 -0700
List-post: <">>
On Mon, 12 May 2008 20:50:45 -0400, Gary Schafer wrote:

>Would the trees absorb a lot of energy if a vertical was placed in the
>middle of this mess with radials lying in the mostly wet ground?

Based on my experience and those of some neighbors in dense redwood forests, 
I'd say verticals will work well on 80M and 160, and probably on the other 
HF bands. Expect absorption to increase drastically at VHF and UHF. However 
-- take a look at my website for a piece comparing verticals and dipoles in 
an NEC model. I have the top of a vertical half-wave dipole for 40M 
suspended at roughly 110 ft in a tall (170 ft) redwood. Horizontal dipoles 
at 110 ft work MUCH better, and results are reasonably consistent with NEC. 
The tree is not in the model. 

One of the projects I want to try is comparing a vertical out away from  
trees to the existing vertical close to the tree to see what, if anything, 
the tree is doing.  This is a BIG tree, roughly 5 ft in diameter at the 
base. Photos near the end of the coaxial choke power point on my website.


Jim K9YC


TowerTalk mailing list

<Prev in Thread] Current Thread [Next in Thread>