[TowerTalk] insulated wire as radials and antennas.

Tom Rauch w8ji at contesting.com
Tue Feb 22 18:57:01 EST 2005


> I have 100 BARE COPPER radials pinned to my lawn and
waiting for Spring growth to absorb them into
> the thatch.  Do I have to worry about small animals or my
XYL walking out there when I'm
> transmitting?  Or is the concern only when the radials are
elevated?

The nice thing about large non-resonant systems is the
fields are distributed over a very large area. That means
voltages and currents in and around any particular conductor
are much lower than small resonant systems.

If you had 2000 volts at the end of four radials, you can be
certain you'd have much less than 1/25th of that voltage at
the ends of your wires. You'll have much less problem with
common mode currents on the feedlines, and less unwanted
coupling into other objects around the radials.

When I walked under the 20 or 30 foot high elevated radial
system (six radials) at a 5kW BC station, a short wire tied
to my belt that was dragging on the ground actually arced
right through my jeans. Ouch! We could light a florescent
bulb by holding it a few feet above ground near the radials.
When we added 120 radials, everything totally cooled off and
the FS came up between 2 and 5-1/2 dB depending on distance
and direction. We could grab right on radials bare-handed
and not feel a thing.

73 Tom



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