The F12 suggestion works fine IF the parasitic element
can be SPLIT in the middle. The CC Reflector is CONTINUOUS
at the center. I suppose one could tune the DE as a reflector,
then use THOSE dimension to adjust the reflector (*assuming*
the loading from the coils will be identical), then retune the DE
to the middle of the band.
Tom N4KG
On Mon, 19 Feb 2001"N2TK" <tony.kaz@verizon.net> writes:
> Why not do like Force 12 recommends for their 40m beam?
> Haul up the driven element and tune for resonance on 30m with a
> balun and coax attached. Then attach a balun and coax to the reflector
and
> haul that up and tune it as a reflector.
> Then put both on the boom.
>
> Tony
> N2TK
>
> -----Original Message-----
> From: towertalk-admin@contesting.com
> [mailto:towertalk-admin@contesting.com]On Behalf Of n4kg@juno.com
> Sent: Sunday, December 08, 2002 13:43
> To: TOWERTALK@contesting.com; TNeill1648@aol.com
> Subject: Re: [Towertalk] 30 Meter Beam
>
> Hi Tom,
>
> I would start by removing the Capacity Hats,
> then slide the element tips in until you obtain
> resonance at the desired frequency. Tune
> the reflector to be 3 to 5% long.
>
> You can grid dip the reflector (standing alone)
> by placing a wire across the center of the
> element using a pair of hose clamps and
> putting a one or two turn coil in the middle.
>
> The element will need to be reasonably
> high above ground, say 30 ft or more to
> prevent detuning by the earth. If there is
> not enough tuning range, it may be necessary
> to use a coil with fewer turns.
>
> It is probably easier to retune linearly loaded
> elements such as the HyGain, KLM, and F12
> by simply placing a jumper across the linear
> loading transmission line.
>
> It appears that a 2L30 can be placed inside the
> elements of a 2L40 with little or no interaction,
> assuming the Boom is strong enough.
>
> Tom N4KG
>
> On Fri, 6 Dec 2002 11:28:50 EST TNeill1648@aol.com writes:
> > I have an old Cushcraft 2 element 40 that I am going to convert to
> a
> > 2
> > element 30 meter beam. Just wondered if anyone has done this or
> > have and
> > recommendations. Thank you.
> >
> > Tom K4XG
> >
> >
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