[TowerTalk] Fw: F12 EF-240/230

[N4BAA - Jose Castillo]

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 at earthlink.net>
> To: <towertalk at 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 at contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
> 
> 
> 
>