Dave,
My strong opinion is that if you use a good modeling program you can
build it and put it up without any need for adjustment. Also, in order
to add the inductor you will need to not only insulate those elements
but split the halves as well. I think the potential problems as a
result of having another thing that could go wrong outweigh the
potential benefit of being able to do some tuning at the center of the
element.
My elements are all insulated using element plates made from G10. The
driven element is also split using a solid rod of fiberglass.
With elements that start at 2 inches OD, you will need to have some
pretty good trusses, depending on how much wind and ice you want it to
handle.
Stan, K5GO
----- Original Message -----
From: "David Jordan" <wa3gin@comcast.net>
To: <towertalk@contesting.com>
Sent: Monday, September 21, 2009 12:22 PM
Subject: [TowerTalk] HB 3 ele 40m Beam
> Hi Folks,
>
>
>
> Finishing up final mechanical plans for the antenna and was wondering
> if
> there is any consensus with regard to insulated parasitic elements.
> The 2"
> OD elements I'm using fit nicely into Electrical UV resistant PVC
> which
> would allow for insulating the elements from the mast. I also thought
> it
> would aid in final tuning if I utilized a small amount of inductance
> at the
> center of the director and reflector to fine tune those elements.
>
>
>
> Thoughts welcome,
>
> Dave
>
> Wa3gin
>
>
>
> P.S. boom 48ft., Full-size or slightly less to accommodate center
> tuning
> coil inductance.
>
> _______________________________________________
>
>
>
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