I am about to erect an antenna for Top Band, I've found an article on the Web
from an old issue of Ham Radio magazine, where W6SAI described the evolution of
a 3 wire inverted L for use in a small garden/city lot. The antenna is based
on a 135 foot (35 up 100 out) inverted L, this single wire antenna was adapted
to use 300 ohm ribbon, and then to a system with three wires with the centre
conductor going to the transmitter and the outer two being connected to ground
at the feedpoint.
The claim is that using this system the efficiency of the antenna was raised to
over 80 %.
I have to admit to "knowing enough theory to be dangerous", and it may well be
that the much missed W6SAI was correct, my gut feeling is that this may be
another occasion where feedpoint impedance is translated to radiation
resistance - can any of you who understand the physics and especially the math
please tell me whether I'd be wasting a lot of time and effort making up the
spreaders etc for such an aerial with respect to a single-wire Inverted L?
And finally, I tried a rather novel Top Band antenna last Winter KE4UYPs "Top
fed linear loaded" dipole arrangement with 132feet out and 170 feet of linear
loading in the other leg at two foot intervals, this enabled me to span the
"pond" with 80W and increase my country score quite well, the downside of this
antenna is that if like many of us you share the Antenna space with the XYL who
for some strange reason considers that plants should be grown etc, that you can
have a real problem with the up and downs of the linear loaded bit... but I
mention this as it may be an antenna worth trying for those without the space
to erect a full sized Top Band dipole.
I would be grateful for any constructive ideas on the W6SAI antenna
Thanks and good hunting
Tony G 3 Z R J
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