[TowerTalk] 4 square for 80

[Fernando González, EC1CT]

Hi all,
I´ve been following this thread with much interest. Just wondering if anyone 
tried a 4 square for 80 meters using vertical dipoles as those described by 
N6BT or even Sigma Verticals from Force 12.
I just ordered a couple of N6BT Bravo vertical dipoles (80 meters 
monobanders) and my plans are to set them on phased (1 driven plus 1 
reflector) for 80 meters direction NW/SE. If the perfromance is
ok, I´ll try a 4 sq. I don´t really have space for radials so a real 
vertical antenna is not an option. Thanks and best 73
EC1CT Fernando
ec1ct at esbesaya.com

>
> 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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