Henrik Weiss wrote:
>
> Gareth,
> I think the antenna you are reffering to is also called the half Bobtail
> curtain version. If i am right you have two 1/4 wave verticals spaced 1/2
> wavelength and connected at the top with a horisontal wire ??
>
> I have a bobtail curtain for 40 meters and the spacing i abt. 0.8 of a 1/2
> wavelength because of some existing supports. This cause the horisontal wire
> to "drooping" a bit. I do not find any degradation with respect to F/S
> attenuation it is still 10 - 15 db and I suspect the gain is the same as my
> earlier " ideal " setup.
>
> Henrik
> Oz1ing
> -----Oprindelig meddelelse-----
> Fra: Gareth Crispell <gareth@capecod.net>
> Til: towertalk@contesting.com <towertalk@contesting.com>
> Dato: 14. marts 1998 01:52
> Emne: Re: [TowerTalk] Half-square antenna question
>
> >stu wrote:
> >>
> >> I was looking at some drawings of half square antennas and while most
> >> articles said the bottom legs could be bent around without losing much
> >> gain I am wondering how much effect moderate drooping or bending between
> >> supports of the top horizontal part it would take to degrade
> >> performance? I don't have any 3 supports near a straight line so it
> >> would be fairly dog legged.
> >> 73' Steve KG8TX
> >>
> >> --
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> >
> >You only need two supports for the half square. The "bottom legs" are
> >vertical radiators and should be as close to straight up and down as
> >possible. Think of this antenna as 2 quarter wave verticals phased by an
> >electrical half wave. I would put as little sag as possible in the 1/2
> >wave horizontal. You can anchor the bottom of the verticals with fishing
> >line tied to a cinder block so they don't wip around in the wind. The
> >bottoms only need to be about 6 to 8 feet off the ground. Tune to
> >resonance with this ratio. For every inch you cut from the feed side
> >vertical - cut 3 inches from the far end. Bring the feed line away at a
> >sharp angle so the horizontal part does not electrically "see" the
> >feedline. Darn good antenna and cheap to build. Low lift angles.
> >
> >de N1MSV
> >--
> >
> >
> >
Hello Henrik This is correct. Both names are applied to the same
antenna. I do believe the antenna was first refered to as the half
bobtail, although in the last 15 years or so it is most commonly refered
to as the half square.
de ... N1MSV
> >
> >--
> >FAQ on WWW: http://www.contesting.com/towertalkfaq.html
> >Submissions: towertalk@contesting.com
> >Administrative requests: towertalk-REQUEST@contesting.com
> >Problems: owner-towertalk@contesting.com
> >Search: http://www.contesting.com/km9p/search
> >
--
--
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