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Shortened verticals

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Subject: Shortened verticals
From: Rolfe Tessem" < (Rolfe Tessem)
Date: Sun, 08 Dec 96 09:39:44
On Sat, 7 Dec 1996 17:45:43 -0500, Rick Markey wrote:

>Just talked to a guy using MFJ 1793 verticals in a four square.  He told me 
>that he knows of several others doing the same thing.  I heard the array 
>and it sounded impressive, and the guy who built it is very happy with it. 
> He's using 72' spacing.  Says that works better.  Also, he was using 8 
>radials under each vertical and a Comtek switch/phase system.
>de Rick, KN3C
>From:  Howard Brainen[]
>Does anyone have real world experience with arrays of shortened
>verticals?  I'm familiar with the recent articles on top
>loaded hanging wire arrays, but I'm wondering about commercial
>80m and/or 160m loaded verticals, like the GAP and the
>Gladiator.  Anybody tried a four square with the Gladiators, for
>Howard WZ6Z

I'm using four of the MFJ 1993 top-loaded verticals in a 4-square and they work 
very well. I put up one in 
April as a reference and used it for several months to get a feel for what one 
would do. This had 50 
radials under it. My take on it is that it gives up very little or nothing to a 
full-sized vertical, except for the 
obvious bandwidth limitation due to the loading. When my field was mowed in the 
fall, I put up the other 
three and have actually had them on the air for just a couple of weeks. I'm 
using conventional spacing 
(65 feet, 2 inches) for the SSB DX window. Due to the weather moving in, I only 
had time to put 25 radials 
apiece under the other three verticals, and I'll increase that  if the snow 
melts or, failing that, in the Spring 
:-). 8 radials is too few for a conventional ground-mounted vertical. The 
literature is pretty clear that the 
point of diminishing returns comes at about 60 radials. Purists will use 120.  
I still have some tuning and 
tweaking to do, but I can definitely recommend this combination. The Comtek box 
works as advertised, 
of course.

I don't know much about the Gladiators, but they look like good antennas. The 
Low-Band Monitor had 
an article some time back about the Uni-Hat vertical on 160 and gave it good 
marks. I'm sure a 
4-square of those would work well (and would be pretty darn expensive too).

Rolfe, W1VC

Rolfe Tessem                  |                 Lucky Duck Productions, Inc.                 |                 96 Morton Street
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