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Re: QFH modification



I have built many QFH antennas and never found it necessary to use coax to
obtain a good match. All that is needed is a good balun, Bazooka, Split
Sheth, or Volute to make the antenna work. It must be a ballanced feed for
best operation.
Art ,KC6UQH
---- Original Message -----
From: "SV1BSX" <sv1bsx@yahoo.gr>
To: "Amsat-BULL" <amsat-bb@amsat.org>
Sent: Wednesday, March 16, 2005 11:26 AM
Subject: [amsat-bb] QFH modification


> Hi Amsat s,
>
>    I wondering if has significant difference in the behavior of QFH
antenna,
> if we replaced the UT-141 section on Domenico's design or the "hard line"
> in the US-model, with a soft copper tube which has inside  a piece of
> Coaxial cable
> with smaller diameter of tube's diameter (RG-174?) till the N-type
connector
> (pre-amp input).
>
>  Actually, for many of us is very difficult in some cases to find a piece
of
> "hard-line".
> The QFH antenna is simple and effective, I know that because I've tested a
> QFH, but
> this piece of coaxial is a big trouble !
>
>  On the other hand, I saw several models around Internet, without this
> technique.
> They have a simplest feeding method: the coaxial pass through the
> plastic-tube (and QFH)
> and is connected in the upper-point of QFH.
>
> Question:  is it accurate this method? if not, the modification with
> copper-tube including a smaller coaxial cable is it acceptable?
>
>  Any comment is welcome.
>
> 73, Mak SV1BSX
>
>
>
> sv1bsx@yahoo.gr
> http://www.qsl.net/sv1bsx
>
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