[TowerTalk] Stacking vert & horiz 2 meter beams
Ian White, G3SEK
G3SEK@ifwtech.demon.co.uk
Tue, 21 Apr 1998 07:27:58 +0100
Scott Neader KA9FOX wrote:
>
>14 feet above tower: 13 element Cushcraft 2 meter beam, horizontal
>10 feet above tower: 12 element Cushcraft 2 meter beam, vertical
> 6 feet above tower: 6 element Cushcraft 6 meter beam
> 1 foot above tower: 9 element C4XL beam
>
>Will the two 2 meter beams mess each other up?
>
Probably not, because they're cross-polarized... but you've overlooked
two more questions that may be even more relevant.
1. Will the horizontal beams mess each other up?
You need to check whether / how much the apertures of the various
antennas will overlap - see my web pages for diagrams. (The data you
will need are CC's recommended stacking distances for two each of the
same antennas.) For a definitive answer you'd need to model it.
2. Will the mast and the feedline mess up the vertical beam?
Yes, they will. You'd need to model your situation to see how much, but
it could knock several dB off the forward gain. The web pages by F/G8MBI
on crossed yagis will tell you much more than you ever wanted to know
about this (accessible from my front page).
73 from Ian G3SEK Editor, 'The VHF/UHF DX Book'
'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.demon.co.uk/g3sek
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