I concur that the 402CD is resonant around 18mhz as a third harmonic rather
than 21mhz because of the loading. It's not a half-bad antenna on that
band.
I can guarantee you will have at least some interaction between it and any
18 mhz antenna on the same tower, let alone 8 ft away. Not a good bet!
I'd put up a 24 mhz yagi and use the 402 on 18 mhz unless you have another
tower.
If you decide to put it up anyway and have a lot of problems, you could try
turning it 90 degrees from the 402 and see what happens. It'll probably
decrease the coupling greatly, but you'll have larger sidelobes (certainly
the lesser of two evils).
73, Tyler K3MM
To: towertalk@contesting.com
cc: (bcc: Tyler G Stewart/BENN/CEC)
Subject: Re: [TowerTalk] 40-2CD Spacing and Interactions with WARC?
David O Hachadorian wrote:
> It was probably one of my postings where you heard that the
> 40-2cd is resonant at 18.1. I use it as my one and only
> antenna on that band, and it works well, with an swr of
> about 1.9. It is quite possible that it would interact with
> other 18 Mhz antennas. In fact, after my last posting,
> somebody, I don't remember who, wrote me that
> he was having such a problem.
Does anyone have any other experience with interaction between the
40-2CD and an 18 mhz.antenna? I'm about to put the 40-2CD on a mast
about 8 feet from a Hy-Gain DB12-17 duobander. Any comments please?
Dan, W4EA
w4ea@contesting.com
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
|