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
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|