Here is a copy of something I just posted on the 160m reflector, and
on the topband reflector. The snake antenna is really just a random
wire laid on the ground. It may have specific construction details,
but in reality it is a random hunk of wire laid out on the ground.
Before or after trying a "snake", I'd compare it to other wires I
already had up.
copy follows:
This question comes up frequently, and a brief summary might be
useful.
Magnetic loops can offer improvement in S/N if you have local noise
from one primary direction. For skywave noises or QRM, they are
somewhat useless. The "shield" is meaningless, except a properly
implemented "shield" can sometimes improve balance of the loop. They
are really NOT magnetic antennas, except immediately next to the
antenna. At a distance of about 1/10th wavelength or so a small
"magnetic" loop's response is primarily electric, and at about a half-
wave or further they are no different than any other antenna type you
might use. In a location free of noise or interference coming from
one well-defined direction in the loop's null, they generally will
*not* improve S/N ratio.
K9AY Loops, Flags, Pennants and EWE's all work on the same
principles, since they are all small terminated loops. They behave
like small two-element vertical arrays, with an internal phasing
system. The termination insures each "vertical" element has equal
current, phase is inherent in the design and comes from the
horizontal component of the wires. They are primarily useful when
noise or QRM is directly off or near the rearward direction.
These loop antennas (even the single unterminated loop) are all
moderately low-impedance antennas, and despite rumors you CAN use a
metallic mast with any of them as long as the mast is isolated from
the element, not much taller than the antenna, and non-
resonant.
Snake Antennas are really just a "random luck" antenna. There isn't
any science, reliability, or planning to successful installations.
Sometimes you'll find a wire or antenna that helps under some
conditions. It might be an antenna for another band (like an 80-meter
dipole) that just happens by random chance to work, or it might be a
wire strung out on the ground like a snake.
One thing all these antennas (like most smaller 160 receiving antenna
system) have in common is results will vary greatly with each
individual application.
73, Tom W8JI
W8JI@contesting.com
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