[TowerTalk] Pre-Installation Tuning of Cushcraft TEN-3 Yagi

[N7mal]

Follow the directions.....

MAL
N7MAL
BULLHEAD CITY, AZ
http://www.n7mal.com
Everyone in the world is
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----- Original Message ----- 
From: Jason
To: towertalk at contesting.com
Sent: Friday, July 04, 2008 22:25
Subject: [TowerTalk] Pre-Installation Tuning of Cushcraft TEN-3 Yagi


I am in the process of checking SWR prior to installation of a TEN-3 Yagi (3 
element Yagi for 10 meters).  The Cushcraft documentation states that I 
should temporarily mount the antenna with the boom vertical and reflector 
atleast one foot off the ground on a non-metallic support.

I have it 6 ft. off the ground mounted on a fiberglass ladder (non 
conductive).

Using an MFJ-259 SWR Analyzer, I recorded the following data after adjusting 
the match on the driven element:
      Frequency     SWR
      28.205 3
      28.346 2.5
      28.482 2
      28.549 1.7
      28.618 1.5
      28.68 1.2
      28.828 1
      28.939 1.2
      28.979 1.5
      29.0298 1.7
      29.076 2
      29.158 2.5
      29.227 3



My goal is to tune this antenna for a resonant frequency of 28.3MHz and I 
have matched the dimensions provided by Cushcraft towards this aim.  I have 
tried extending the dimensions of the driven element by 2" but only moved 
the resonant frequency down to 28.647MHz.

My question is whether  I should trust the Cushcraft documentation and put 
it up as they have described, assuming that the close proximity to the 
ground is disturbing my measurement.

Thanks for any help / advice you can provide!

73 de KB5URQ

Jason