Topband: Beverages through the forest
HA0DU Steve
ha0du at dx.hu
Tue Oct 27 03:26:44 PDT 2009
Dear All,
When 12 years ago we moved to a one-hectar farm in the middle of a
20,000 hectar forest, I had doubts if I can make antennas tall enough to
"be heard". I also saw that the maximum wire length within my property
was about 140 meters in the diagonal. I needed something longer, so I
looked around...
Our only neighbor was the forester, who told me I can hang up wires
anywhere, any length, provided nobody gets strangled. So I used the
unlimited space to install 11 identical Beverages, each 176 meters long.
I made some comparison tests and found that over sandy terrain the
optimum height was 10 to 12 feet. I am also using #12 AWG stranded
insulated wire.
Over the years maintaining 11 wires became unnecessary, so today I only
have 3 (NW, NE and S), but each of them are 1,600 feet long. (For TX5C I
had to extend the NW Bev to 2,400 feet). I also changed the hanging
method. Originally I attached the wire to the trees by thin nylon ropes
(bailer rope), so the wires were really zig-zagging. Instead now I put
pieces of bailer rope between pairs of old trees along the path, and the
Bev wire is attached to these, which results in less zig-zagging and
larger distances from trees. The ropes are a little loose, so even if
these old trees are moving in the wind, the ropes are not broken. I may
be wrong but I thought perhaps when the wire is very close to a live
tree it forms some kind of a capacitor and I did not like it. With the
new method I have about 40-50 suspension points at each of the Bevs, and
maintenance is easy, using a small stepladder and a reel of bailing rope
in a backpack.
Although I have a preamplifier, I do not use it very often, it is just
not necessary in such a low noise environment. There is no other house
with electricity in a 1 km radius and our electricity supply is a ground
cable. In fact when there is something very important, I even turn
refrigerators and all other household electrical equipment temporarily
off, so that I minimize the man-made noise. For the eleven Beverages I
also used to have a selector switch, but now I just connect the right
antenna coax to the RX ant input of my receiver.
If it works? Yes indeed, I tried all kinds of small receiving antennas
including pennants, flags, magnetic loops, slinkies, mostly everything I
found in the literature, but the Beverage outperformed all of them. Very
soon you can listen to some of the recordings I made on 160 meters at
http://ha0du.com
Best 73
Steve HA0DU
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