Hi Bob -You are probsbly aware that the slopping top load wires have a
vertical componemt in their current which will subtract from the desire
vertical componemt of the main element. Granted it's near the end of the
antenna so there won't be a lot of current in the loading wires and the
nearer it is to horizontal the smaller the vertical current component.
Bottom line make the vertical as tall as possible and the loading wires as
horizontal as possible and try to keep the horizontal top loading wires in
ballanced pairs to preserve the omnidirectional. pattern.While all this
makes good theoretical sense in the real world you would have to be way off
to see much difference.
Gene / W2LU
----- Original Message -----
From: "Robert Pack" <nx5m@txcyber.com>
To: <towertalk@contesting.com>
Sent: Tuesday, November 24, 2009 12:01 AM
Subject: [TowerTalk] Variation of Vertical T
>I have a bit of a dilemma for the short term. While the construction is
>going on to erect a true elevated 160m vertical (36 foot high base,
>insulator then 120 feet above that) I need an alternative vertical for 160.
>My preferred choice at the moment is a top loaded T but current
>circumstances just are not going to allow me to string up such an antenna
>between towers. I had to remove the one I had up......or better
>yet........mother nature removed it for me and I cannot put it back up
>right now.
> I do not want an inverted L although it is probably the easiest thing to
> do....but I do want a vertical. I also do not want to shunt feed a tower
> and put down miles of radial wire.
> With a top loaded T antenna in mind.........I put the vertical wire on
> supports up my 40m tower with the feedpoint 10 feet above the ground to a
> point at 105 feet up the 40m tower (95 feet of vertical wire) and instead
> of the top loading being in a T configuration I just slope those two wires
> at 45 degree angles downward.
> Does it matter if the top loading wires are really horizontal or can they
> be sloped as described above?
> I am assuming the feedpoint will be about 35 ohms so a pair of 75 ohm
> lines should accommodate that ok.
>
> Anyone have any valuable input on this issue?
> If I can make it work it will be a nice backup antenna for the future.
>
> Bob NX5M
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