A dipole antenna just will not work unless it is at a sufficient
height. The multiband dipole I describe in another article could have
another wire added for 160 Meters. But the repeating resonances at 2
Mc intervals would have detracted from its performance. Even if you
managed to get it to ¼ wave up at 160 Meters, about 70 feet,
it would be problematic. The extended G5RV and other flat tops are
just dipoles with a different feed method. For that matter, the off
center fed types like the Carolina Windom are the same stuff. End fed
long wires must be hung at similar height to get the performance to
be heard well. 120 feet or more is required for long haul work.
A vertical would be a mechanical monster, and cost a fortune. Or the
loading coil would reduce bandwidth and radiated signal. I did a
helically wound 160 Meter vertical about 25 feet tall, but it was
like erecting a wet spaghetti noodle. And it was mounted over a
ground screen which used up two ¼ mile rolls of electric fence
wire. It did work for DX, but was lousy for local ragchews beyond
ground wave distance. At high noon, I was able to talk direct to Long
Island with 100 Watts during the summer to another station using a
similar vertical on ground wave.
You hate to climb trees. And you have no tower, but want to work short haul on 160.
The theoretical length for a full wave loop is:
| Circumference (in Feet) = 1004 / Frequency (in Megacycles) |
This works out to a total length of wire of 500 Feet. This is available as
a spool of #12 or #14 THHN wire at Lowe's for less than $50. Use
black insulation for stealth. The wire will not cut to formula length
with insulation, but it is a starting point.
The insulators are available at Agway or a farm store. They are electric
fence insulators. Cheap plastic insulators work just fine, since the
loop is a low impedance device.
For heights of 20 Feet, a loop will outperform a dipole or anything else
at the same height. In fact, it KICKS A** by comparison. Under good
band conditions, I have worked the west coast of the USA with 100
Watts presumably on multihop. I think I might be able to do europe
this winter. But it is NOT a vertical over a good ground for DX, so
don't count on it.
IMPORTANT: DO NOT WASTE MONEY AND RF ON A BALUN FOR THIS ANTENNA. The tuner
takes care of it.
My electric fence antenna runs from tree to tree in a rectangle 100 feet
by 125 feet. No coax is used. One side of the antenna goes directly
to a ground stake, for lightning protection. A ground wire to the
pass through panel in the double hung window by MFJ completes one
side of the loop. The other side goes to the center of a coax
connector on the panel. Impedance is about 150 ohms. That connects
via a short piece of coax inside the house to my antenna switch and
For low heights, a 75 meter loop also is a good choice, if you cannot
erect a higher dipole. I took down my 75 meter loop to make room for
the high dipole described in my other article. As a plus, it will
keep your giraffe herd safe at home.