[Lowfer] Antenna questions

[Stewart Nelson]

Hi all,

I will be returning to the Reno, Nevada area at the end of January,
and am considering building a Lowfer beacon.  Because of my distance
from most of you, I need to put out a decent signal.

I have a pasture area, about 230 feet on a side, that has no trees
or structures on it, and is quite dry in the winter.  So I believe
that a vertical antenna may be best, even though they are out of
favor these days :)

I have a rough idea for a design, but there are three big questions:

1. Is it legal?
2. Will it have good efficiency?
3. Can it be built so it will stay up for a while?

Sorry that I don't yet have a drawing.  Just as the present Tx loops
are part of a 50x50 square, my antenna is part of a 50x50x50 cube.
Start by imagining such a cube, with a pole occupying a long diagonal
(approximately 86 feet long).  Of course, in operation, the (virtual)
cube is on end, so that the pole is perpendicular to the ground. From
the top of the pole, three 50-foot "top hat" wires extend outward and
downward, along three edges of the cube.  At the bottom end of each
top hat wire, there is an insulator, followed by additional wire (or
nonconductive cord if needed) to reach an anchor in the ground.  At
the required angle, the anchors are each about 122 feet from the base
of the pole, and the bottoms of the top hat wires are about 58 feet
above the ground.  There would be additional guy wires/cords as needed
for stability, and 6 to 12 ground radials (each about 100 feet long)
to complete the circuit.

I have heard that there is a huge performance penalty for down-sloping
top hats, but would think that, since the top hat current decays
roughly linearly to zero along the wire, and the starting value is the
minimum in the pole, the system should be at least as good as a 72-foot
pole with three horizontal 41-foot top hat wires.  Have I gone astray
here?  Is there software that can model such an antenna accurately?

Other electrical questions:  Are metallic guy wires a problem (if
properly insulated)?  How much improvement does additional ground
radials give?  Is it worth putting ground rods at their ends?  Should
I use chicken wire near the base?  How large an area should it cover?

Some mechanical questions:  I would like this to be as unobtrusive as
possible.  What is the smallest (or least visible) suitable material
for the pole?  TV mast?  Conduit?  Water pipe?  How many sets of guys
are needed for stability at this height?  I would like it to be able
to withstand an occasional gust of up to 60 mph, but if it came down,
it would not be a disaster, since it would be in a location where
injury or property damage would be unlikely.

Sorry for all these stupid questions, but I am a complete newbie
when it comes to antennas.

Thanks and 73,

Stewart KK7KA