Date: Wed, 5 Apr 2017 13:37:57 -0400
From: Dave Sublette <k4to@arrl.net>
To: Central KY CW/DX Operators <CW-DX-OPS@LSV.UKY.EDU>
Cc: towertalk@contesting.com
Subject: [TowerTalk] Four Square notes
For the past 10-15 years I have had a four square array on 80 M. I use the
Comtek phasing system. My array consist of four, full sized, dipoles strung
around my 160 meter vertical. The insulated feed point on the vertical is 27
feet above ground, which makes the tower 150 feet tall, perfect for the 80
meter stuff.
The centers of the dipoles are pulled out to 46.5 feet from the center, making
the side of the square 66 feet as required for the array. The lower halves of
the dipoles are brought back to the center and fastened about 20 feet up the
tower, making the lower half sort of droopy and loopy. This configuration is
not ideal, but I was able to get a 20 dB f/b out of it and it worked fine for
many years.
I?m not quite finished with the job. I have one dipole restrung and am working
on the second of the ?good? dipoles. The other two will have to wait until I
get some fresh RG59/U in from somebody.
FYI? the ?80M? dipoles resonate at 3300 KHz for proper operation. The feed
lines are cut to an electrical three-quarters wavelength measured at 3600 KHz.
73,
Dave, K4TO
## How close to the top of the tower are each of the 4 vertical sloping
dipoles ? Do they require spreaders to space them out from the top of the
tower ? Is any type of CM choke used at the feedpoint of each vertical
sloping dipole?
Is there a CM choke on the main input of the comtek phasing box ?
Jim VE7RF
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