KV4FZ wrote:
>The DXE specs call for a 400-500 ohm open wire or ladder line which I do not
presently have. A hand made line of 600 feet is not an easy chore.
It may not be as bad as you think! I
believe the following would be closer to
4-500 ohms than anything you are proposing:
Buy a 1/4 mile roll of 17 Gauge Aluminum
Fence wire from your farm supply store. This wire
has extremely low weight per length and can be
stretched very tightly. I suspect it would need
only 2 intermediate supports between the ends (i.e
about 200' per span). Build 2 supports with the
desired wire spacing and perhaps one intermediate
spacer for each span (i.e. 3 total). I don't have
the formula in front of me but I guess 3-4" spacing
would be in the ballpark for 17 Gauge wire to be
around 4-500 ohms. You can connect Cu to Al wire
easiest if you use twist electrical connectors with
a dab of Noalox inside each. I would slope each
end of the wires down to a stake and stretch it as
tightly as I could. This should allow you to need
only 2 intermediate supports with very low sag. One
set of spacers between supports would then make 100'
spans without any physical spacers, but if you stretch
the wire very tightly I suspect there would be little
variation, even in a brisk wind.
Hopefully someone will calculate the exact
spacing for #17 wire to yield 400-500 ohms, but I'm
guessing 3-4" should be fairly close. The key to all
of the above is stretching the wire VERY TIGHTLY!
73 & GL!
Bill W4ZV
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