[TowerTalk] Speaking of wire mesh...

[Wes Attaway (N5WA)]

When placed on, or below, dirt galvanized wire rusts away pretty fast here
in Louisiana.  After a year or two I wouldn't want to be depending on it for
anything important.  Using copper wire might seem more expensive, but when
everything is considered I doubt that it would be.

------------------ Wes Attaway (N5WA) ------------------
1138 Waters Edge Circle - Shreveport, LA 71106
    318-797-4972 (office) - 318-393-3289 (cell)
        Computer Consulting and Forensics
-------------- EnCase Certified Examiner ---------------
 

-----Original Message-----
From: towertalk-bounces at contesting.com
[mailto:towertalk-bounces at contesting.com] On Behalf Of jimlux
Sent: Sunday, January 17, 2010 2:13 PM
To: Tower and HF antenna construction topics.
Cc: n4zr at contesting.com
Subject: Re: [TowerTalk] Speaking of wire mesh...

K1TTT wrote:
> They may not be perfect, but they do help.  I use that stuff under my 80m
> 4-square... even with the radials raised up 10' putting 150' of that stuff
> under each vertical was still a measurable change to the impedance when I
> was putting up the first one and testing it.  I got it in 100' sections
from
> a local fence installer and put 100' out from the center of the 4-square
as
> far as it went past each vertical, then a 50' piece at 90 degrees to it
> crossing at the base of each vertical.  A 1/8" galvanized cable clamp does
a
> good job of clamping without need for matching metals if you use
galvanized
> wire, then use a bigger galvanized clamp to attach to the tower rung.
> 
>
The question I would have is whether you'd be better spending money on 
copper wire for radials than spending it on steel mesh.  Obviously, if 
one has a cheap source for either, than that might push you one way or 
the other.

For tesla coils, which are entirely a near field thing (100-200 kHz), 
mesh works great, but there, it's because the mesh makes a more uniform 
electrostatic field.. the advantage is in the field shape more than the 
loss effects.  The mesh is basically one plate of a capacitor.

But for antennas, I'm not so sure.

However, it occurs to me that this is something that NEC4 can model 
(albeit tediously), except for the permeability of the wires.
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