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Re: [TowerTalk] F12 EF-240/230

Subject: Re: [TowerTalk] F12 EF-240/230
From: "Joe, aa4nn" <>
Reply-to: "Joe, aa4nn" <>
Date: Sat, 22 Oct 2005 15:28:18 -0400 (GMT-04:00)
List-post: <>
Hi Roger,

Please check that you have placed a short wire jumper
across the "feed point" of each reflector element and
that you have installed a "hair pin tuning coil" across
the real feedpoint of each driven element.

Make sure your loading wires are correctly installed
on the correct stubs out there where the insulator is
in each half of the antenna element.  Make sure the
loading wires are not touching any antenna element
as you raise the antenna for test.  Make sure the truss
wire is not laying across the tuning wires.

My shorting wire jumper for the 40m loading wires
needed moving a few inches away from the factory
suggested position, effectively shortening the 40m
elements.  Both 40m and 30m have fairly broad 2:1.

Assembled properly, the antenna should be showing
you good SWR near your target frequencies at the
25 foot height you are using for tuning the elements.
After finding lowest SWR at your target frequency by
adjusting the shorting wire jumpers, spread or compress
the hairpin coils to get SWR down to 1:1 or so.

73, Joe, aa4nn
Owner of an EF240/230 at 102 feet.

> Subject: [TowerTalk] F12 EF-240/230
> I have assembled a Force 12 EF-240/230 (2 element 30 & 40 Mtr 
> on a common
> boom) and have suspended it up 25 feet on a rope between two 
> trees.  I am unable to get the antenna resonant at a 
> frequency that is in either band.
> Email to F12 three days ago was not answered.
> The best tuning is about 1.25 @ 6.7-6.8 Mhz and quite narrow. 
>  On 30 it is
> 1.5 @ 9.8 Mhz.  I do not seem to get the resonant frequency 
> above those listed.  I have tried moving the linier jumpers 
> so they are quite a ways off what the manual quotes but it 
> does not seem to make much difference.  I am using a MFJ259B 
> on about 35 feet of coax.
> Anyone out there had any experience with this antenna and can 
> offer some suggestions?
> Thanks,
> Roger, W7VV

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