Roger...
Just went through this exact scenario this weekend...
Had the exact thing actually...
Make sure you are NOT adjusting the reflector dimensions at
all...ONLY the driven elements...
I installed a homebrew 40M relay in mine and we ended up
shortening my 40 meter jumpers about 15-17 inches from the manual
settings...
30M ended up being about 5 inches shorter and it was perfect then.
We used an ant analyzer and it went fairly smooth...
I can call you if you would like..
73 and GL
Jose - N4BAA
ChetMoore wrote:
>
> ----- Original Message ----- From: "Joe, aa4nn" <aa4nn@earthlink.net>
> To: <towertalk@contesting.com>
> Sent: Saturday, October 22, 2005 3:28 PM
> Subject: Re: [TowerTalk] F12 EF-240/230
>
>
>> 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
>>>
>>>
>> _______________________________________________
>>
>> See: http://www.mscomputer.com for "Self Supporting Towers",
>> "Wireless Weather Stations", and lot's more. Call Toll Free,
>> 1-800-333-9041 with any questions and ask for Sherman, W2FLA.
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk@contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
>
>
>
>
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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