Since they are cable fed in phase, it makes a lot less difference than you think.  Get the measurements as equal as possible and just use it!


> I found this at repeater builders -
> http://www.repeater-builder.com/antenna/440fdipl.pdf
>
> it says 23 inches between each element, mine are from top to bottom - 22
> 13/16, 25 1/2, 22 5/16 then the next set are 22 7/8, 25 5/16, 23 1/16.
>
>
>
>> Well, if the antenna is tuned for a center frequency of 460 MHz., and you
>> run it at 443, then you have to assume some level of mismatch being 17
>> MHz. away.
>> That's simple common sense.  The trick is guessing the possible loss of
>> efficiency and gain that far away.  Good news is, with the dipole design,
>> all the
>> elements are fed with equal lengths of coax, so are fed in phase no matter
>> what the frequency.  Therefore, very little performance difference when
>> off the
>> center design frequency.
>>
>> Paul
>>
>>
>>> I was under the notion these antenna's were primarily made for the
>>> business
>>> band, I thought that was why the SWR was not lower then 1.8, thanks for
>>> your
>>> help, I will have the antenna installed.
>>>
>>> ----- Original Message -----
>>>
>>> Subject: Re: antenna question - from KG8ID
>>>
>>>
>>>> 4.5 of 57.5 watts is great.  Use it!  No, it will not cause any
>>>> problems.
>>>> The antenna should perform very well for you.
>>>>
>>>> I didn't understand your question- "is this SWR showing an antenna that
>>>> is
>>>> tuned higher in the band say for the Business Band?"
>>>>
>>>> Please re-word and I will try to answer.
>>>>
>>>> Paul
>>>>
>>>>
>>>>
>>>>
>>>>> Paul can you answer another question? We took the 8 bay folded dipole
>>>>> antenna to the site and connected it to a Telwave SWR meter and the
>>>>> meter
>>>>> to
>>>>> the duplexer antenna port, the RF power out was 57.5, the reverse or
>>>>> reflected was 4.5, so the calculated SWR is 1.8:1, which is
>>>>> acceptable,
>>>>> is
>>>>> this SWR showing an antenna that is tuned higher in the band say for
>>>>> the
>>>>> Business Band? And after knowing this will the antenna perform good
>>>>> for
>>>>> us?
>>>>> Also in my previous email I misstated the output frequency on the
>>>>> repeater
>>>>> it is actually is 443.45.
>>>>>
>>>>> Perry/KG8ID
>>>>>
>>>>> ----- Original Message -----
>>>>>
>>>>> Subject: Re: antenna question - from KG8ID
>>>>>
>>>>>
>>>>>> Hi Perry.
>>>>>>
>>>>>> A DB420 has plenty of bandwidth to do 448 MHz.  No problems.
>>>>>>
>>>>>> Paul
>>>>>>
>>>>>>
>>>>>>> Can the DB-420 be used at 448.450 transmit with no modifications? I
>>>>>>> acquired
>>>>>>> one for free from a business band system and would like to replace
>>>>>>> the
>>>>>>> Hustler
>>>>>>> Spirit series I am using now, this DB looks to be in good shape as
>>>>>>> far
>>>>>>> as
>>>>>>> harness and connections.
>>>>>>>
>>>>>>> Perry/KG8ID
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> --
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>>>> 11/7/2006
>>>> 1:40 PM
>>>>
>>>>
>>>
>>>
>>