I do have a 4 element Steppir on it, but without modification, the elements
won't add to the top loading, only the boom. Still, it's better than nothing :o)
If I shunt feed it on 160, I possibly could work the Tee in as a reflector.
Might help, might not... Fortunately, I run ummm "QRP" max on 160, so better
quality components are a little less dear...
I assume by 36" or 48" you refer to diameter, versus radius. The mast is 6" in
diameter, with a rectangle cage at the base. Not sure about the mechanics of
mounting the cage near the top, it's not like a lattice tower...
Julius Fazekas
N2WN
Tennessee Contest Group
http://www.k4ro.net/tcg/index.html
http://groups.google.com/group/tcg1?hl=en
Tennessee QSO Party
http://www.tnqp.org/
Elecraft K2 #4455
Elecraft K3/100 #366
Elecraft K3/100 #1875
--- On Wed, 7/14/10, Herb Schoenbohm <herbs@vitelcom.net> wrote:
> From: Herb Schoenbohm <herbs@vitelcom.net>
> Subject: Shunt-fed tower vs. T-vertical
> To: "Julius Fazekas" <phriendly1@yahoo.com>
> Cc: r_bakalov@yahoo.com, topband@contesting.com
> Date: Wednesday, July 14, 2010, 10:06 AM
>
>
> Julius Fazekas wrote:
> > What distance from the tower is a good rule of thumb
> for the cage wires?
> >
> > Three is the minimum, would four be "better", as in
> easier to match, provide better isolation?
> >
> > Pondering this for a 48' mast for 80M, as I don't
> think I have enough on top to make it useful on 160...
> >
> >
>
> A 48 foot pole on 160 without any top loading will result
> in low feed point impedence and low efficiency even with a
> good silver plated loading coil. It still may be better for
> DX than a low dipole. The cage helps as well and 36"
> to 48" are fine...and 4 wires are slightly better than three
> but not much. A 48' tower, appears short, but, with
> some top loading like a tri-bander on top you will notice
> that such a radiator is clearly better than a low dipole or
> inverted "L" in laying out a lower angle DX signal on
> TX. Remember the tower need not resonate on 1.8.
> As with many short 60 degree BC station tower installations,
> so much depends on the ground system and the quality of ATU
> components. The cage can only help making the match
> easier to achieve to a certian degree. If you don't
> have a beam on top of your tower consider constructing a 30
> foot stinger out of graduating sections of aluminum tubing
> or create some top loading by connecting in about 30 per
> cent of your top guy wires if possible as long as the
> downward angle is not to acute and is around 45 degree
> declivity or better.
>
> 73,
>
> Herb Schoenbohm, KV4FZ
>
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