Six elements on a 24 ft boom for 10m seems excessive - even for an OWA.
To: "Joern DK5TT" <dk5tt@opretzka.de>, <towertalk@contesting.com>
Subject: Re: [TowerTalk] 10m OWA 24'
From: "Bob" <rabisch@hotmail.com>
Date: Mon, 2 Nov 2009 16:54:05 -0500
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
If you change the taper or size of the elements it will change the
performance.
Another possibility would be to start with a Hygain 105CA which is on
a 24' boom. By adding one element you can make it into a 6 element
10 Meter OWA on a 24" boom. Using YW (yagi for windows optimizer
program) you can obtain:
(these numbers assume the antenna is mounted at 32 feet)
Freq (MHz) 28.0 to 29.0
Gain (dBi) 15.54 to 15.84
I/I (dB) 22.4 to 23.03
SWR 1.11 to 1.05
Element Taper (in): 1.045 .875 .625 .438
Element Spacing (in): 0 49 68 133 194 283
I can't recall the dimensions or the reference but someone also came up with
a dummy element made out of PVC to rebalance the beam.
Nice way to eliminate the hairpin and have a flat SWR across 1MHz of the 10M
band.
It all depends on what you have available to work with.
Bob
K4QHH
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