[TowerTalk] Cushcraft D40 and Force-12 yagis

john at kk9a.com john at kk9a.com
Wed Oct 18 10:21:05 EDT 2006


You would need to model your system to know the interaction.  Since you are
mounting the 40m antenna 90 degrees to the C31XR, I would suspect that it
would have little effect on the C31XR.  The D40 is more likely to be
effected by the boom of the C31XR.  I'm not sure what the boom length is or
if the elements are insulated.  If the elements are insulated, and the boom
is relatively short (not 1/4wl on 40m) , it should work fine.  I doubt the
220 MHz antenna would have any effect on either, unless it was extremely
large.

John KK9A


To: towertalk at contesting.com
Subject: Re: [TowerTalk] Cushcraft D40 and Force-12 yagis
From: Peter Dougherty <w2irt at comcast.net>
Date: Wed, 18 Oct 2006 00:10:36 -0400
List-post: <mailto:towertalk at contesting.com>

At 11:47 PM 10/17/2006, Tom wrote:

>I have a D-40 mounted 12 feet above a C31XR at 69 ft, so the D-40 is
>at 81 ft.  (Parallel to the boom of the C31, like you describe)
>
>I just got it up 2 weeks ago, but so far no problems on either antenna.

Glad to hear it's working well for you. My concern, though, is the
tight spacing that I've got to play with. In my case there's only 8
feet of separation between the C31XR and 221 antennas. With that
small distance I'm more concerned with interaction than I'd be with
10 or 12 feet clearance.




Cheers,

Peter,
W2IRT



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