[TowerTalk] short radials, spacing

[thompson@mindspring.com]

It may be true that having many short (less than 1/4 wavelengths) is not
effective, but when you make a ground shield
out of galvanized fencing mesh (even chicken coop wire can be used if you
take it up before it rusts) that is very effective.

There was an article by a WB0 (referenced in both the ON4UN and ARRL antenna
book) where he used galvanized fence wire
in two crossing strips.  One was about 30 feet long by 5 feet wide and the
second was 20 feet long by 2 feet.  he measured ground resistance each time
and found that this combo was equivalent to at least 60 radials.  I used
this on an 160 inverted L (I laid the fence wire
mesh on the ground).   Measured Field strength was 3 DBd better on a
commercial field strength meter at 200 feet in 4 directions over the
original with two full length elevated radials.

Using a ground screen is an excellent way to make an effective counterpoise
for either a temporary or permanent system.

Dave K4JRB




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