Your tower is probably close to resonant on 160m. When I have modeled a
wire vertical near my 150' tower, the tower acted as a reflector. You may
be able to get a little gain in a desired direction if you lay it out
correctly and model the system. Also an inverted L will give slight
directivity.
John KK9A
To: topband@contesting.com
Subject: Topband: Ideas for xmit antennas for new QTH in KH6
From: Cqtestk4xs--- via Topband <topband@contesting.com>
Reply-to: Cqtestk4xs@aol.com
Date: Wed, 9 Dec 2015 17:34:06 -0500
Next year I'll be building a new home and station in Hawaii.
40 through 6 meters is already set in stone, but 80 and 160 are still
cloudy.
Here's the setup:
I'm allowed one tower maximum 90 ft. The tower will be 90 ft of Rohn 55
using a K0XG rotating system with two rings. It will be guyed using
fiberglass guys. There will be a bunch of HF VHF stuff on the tower. Three
tribanders, two 12/17 meter Yagis, a 40 meter Yagi and way down on the
bottom
two 6 meter antennas.
The tower sits on VERY uneven ground. Although the lot measures 12
acres, I am using only the top three and renting out the rest of the land
to a
farmer to keep taxes from being crazy high.
The ground is pure alluvial red fine particle soil (no stones) and has a
depth of about 6 feet before hitting rock. Since the east side of Hawaii
gets at least 100 inches of rain a year it is usually pretty moist. I would
assume the soil is at least average or better in conductivity. I can run
ropes, wires etc off the tower at the 80 and 40 foot guy points, but can not
connect directly to the tower since the tower rotates. The is no room for
a rotating dipole on the tower for 80.
I've used quad triangle loops before with the pointed end on the bottom
suspended by wires and am leaning towards that since the ground is so uneven
and the terrain difference would be a real negative for a 4 square (I
think).
On 160 I'm leaning toward a wire vertical suspended from a rope coming
from the tower which would make the antenna about 65 or 70 feet tall and to
compensate for that I would make it a T-top.
For rx I have lots of room to run a 700 -900 Beverage to JA and another to
EU/USA direction, so that isn't a problem.
I do need suggestions for my 80 and 160 tx situation. Any ideas?
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