I have twice used an uncommon method to shoehorn a "T" with a very short
vertical run into a space with short spacing between the available supports. I
have had respectable results both times. I
In both cases, the most vertical run I could obtain was about 35'. I created
what I call a "folded T", using spreaders at the ends and center to support and
stabilize parallel runs of horizontal wires.
In the present instance, at KY4P, my support trees allow only a 70' span
between the spreaders. I have three wires about that length stretched a few
inches apart between the end spreaders. The vertical wire is attached to the
center of the middle horizontal wire. At each end of the middle wire, there is
a jumper to a different one of the outer wires. To clarify, the pattern these
connections at the flattop make is like an extremely squashed "S." This gives
a length of wire from the center connection of the flattop to either end of its
folded wire circuit of a little over 105'. That added to the vertical run is
about 140'. The folding of the flattop seems to have the property of reducing
the effective length a bit, as this antenna is resonant around 1920 kHz,
significantly higher than one would expect for a length of 140'. With this new
little antenna (with to date just 16 radials about 65' long) I have received
good signal reports
in the past couple of weeks from England and Slovenia.
At S92SS, back in the mid-'90's, I used a "folded T" compressed into even less
space. I had five wires in the flattop to achieve resonance with an even
shorter flattop span. I lived in a house in the town of Sao Tome with a very
small, mostly paved lot, so I also had to use elevated radials. The space was
so small that the elevated wires were only 55' long, and only one of those even
ran in a straight line. I tied the elevated radials together and brought them
to resonance in common with a single coil. With this antenna and only about
400 watts, I was able to do fairly well. Among its feats was what the JA's
informed me was the first ever 160 meters QSO between Sao Tome and Japan.
I enjoy the retro look of these antennas. They look like something from the
earliest days of amateur radio.
Even if the solution is not optimum, where there's a will there is usually a
way to get on Top Band.
73,
Charles Lewis - KY4P
(ex - A22AA, S92SS, SV0LM, S9SS)
http//picasaweb.google.com/s9ss160m
_______________________________________________
Topband mailing list
Topband@contesting.com
http://lists.contesting.com/mailman/listinfo/topband
|