[TowerTalk] 160 ant problem

[w8ji.tom]

Hi Lane,


> 30 foot pine tree in the front yard and a 30 footer in the back. I was
> contemplating on if I could put up a shortened version of the T antenna.
The
> T would only be 30 feet high. The horiz. portions of the T would be no
> longer than 50 feet each side. I would want to use rather thin wire,
around
> 18 gauge max, preferrably 20 gauge.


A "T" antenna is a good choice, if you install a good ground. The ground
should use as many radials as possible kept in the straightest line
possible, and you should tie in anything metal (fences, water pipes,
abandoned cars, refrigerators, etc) the radial intersects.

The nice thing about a "T", or any other antenna with top or end
termination with a large hat, is radiation resistance (the useful IRE
definition, not the useless misused definitions) is up to four higher than
the same short radiator without a large termination capacitance. Current is
much more uniform throughout the structure by virtue of the abrupt increase
in capacitance at the end compared to distributed capacitance in the
radiator.

That means you can put a loading coil (if necessary) almost anyplace in the
radiator you like without hurting efficiency!

My favorite stealth antenna is a 40 or 80 meter dipole, with a thin Teflon
feedline. You can use it on a few bands as a dipole, and on 160 as a "T"!

73 Tom

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