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Re: [TowerTalk] 4 square for 80

To: xaxaxaxa yayayaya <cqtestk4xs@aol.com>
Subject: Re: [TowerTalk] 4 square for 80
From: Larry K4AB <larry.k4ab@gmail.com>
Date: Wed, 9 Mar 2016 14:48:21 -0600
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Bill,

Take a look at this.  I think there may have been a QST or NCJ article as
well.
Simple, easy, and effective.  It's what I use.

http://www.k8ur.com/pdfs/array.pdf

73,
Larry K4AB

(Or as you say "Apples and Bananas"!)


On Tue, Mar 8, 2016 at 7:37 PM, Bill via TowerTalk <towertalk@contesting.com
> wrote:

>
> I've always had real high towers and no restrictions on the amount of
> towers I could have.  Out in KH6 it is different....one 90 footer on one
> plot of land.  Since that is a hard and fast rule, the quad loop systems
> for 80 meters I've had on the mainland won't be nearly as
> effective...according to HFTA.  I really can't get enough height for them
> to be real barnburners.
>
> So....I've decided to try a four sqaure.  Soil here is clay and stays wet
> most of the time, plus I have enough room to lay out a good radial system.
> The grouind undulates a bit and slopes about ten feet or so in the
> direction of the Pacific which is about one mile away.  The antenna site
> sits at 1100 feet so the slope once it gets off the antenna site is
> great...about 1 foot drop for every 5 feet of horizontal.
>
> I've decided to go the Comtek route for the control.
>
> Several questions:
>
> First, any thoughts as how the terrain where the antennas are located will
> affect operation?  Also, any thoughts on how the big slope from the antenna
> location to the ocean will affect the signal.  On HFTA it is a big help on
> 80 with dipoles etc.  but I'm not sure how it will affect a vertical system.
>
> Second, I have two ways to go on the construction of the verticals.  I can
> fabricate aluminum full size quarter wave verticals which of course will
> provide decent bandwidth, not as good as four towers, but better than wire
> verticals.  One problem is the location.  The closest element would be
> about 30 feet away from the tower whcih has seven Yagis stacked on it.  The
> other three verticals are about 70-90 feet away(all to one side of the
> tower).  Guy wires are not the issue (Phillystran), but the tower is.  I
> have no way to model this thing so it's pure guesswork how much the tower
> and other antennas (40-6 meters) will affect the signal.
>
> Last, I could run four ropes from the tower at 84 feet and make wire
> verticals in a four square pattern around the tower.  To increase bandwidth
> I am planning on running the vertical wires in a "cage".  from what I've
> read that is the way to increase bandwidth.  The problem with this of
> course is the proximaty to the tower.  All four wires would be within 33
> feet of the tower and the seven HF/VHF antennas.  So, the vertical system
> would "see" the seven antennas and the 90 foot tower.  Again it is guess
> work on my part as to what effect they would have on the four square.  No
> guy wires to consider since I am using Philly.  The other issue is I am
> afraid the 80 meter verticals would screw up 20 meters on my triband stack.
>
> My gut feeling is the aluminum 1/4 wave verticals located slightly away
> from the tower would be less affected by the tower/antnennas.  However, for
> ease of construction I really would like to do the vertical wires around
> the tower.
>
> This is my first foray into four squares  so I would really like some
> opinions from guys who have experience in these matters.
>
> Mahaho for the help!
>
> Bill K4XS/KH7XS
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