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[SMTP:hb@cpimaging.com]
>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
>example?
>
>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.
rolfe@ldp.com | 96 Morton Street
(212) 463-0029 | New York, NY 10014
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