----- Original Message -----
From: "Barry Merrill" <barry@mxg.com>
> I've got a distance of 2400 feet for the long wire
> between two 70 foot high bluffs on opposite sides
> of a saltwater inlet that is shoaled and un-navigable.
>
> I plan on 100 watts, and I'd like to use small wire to
> make the wire less visable, but using the maximum
> SPAN of 1000 feet with #12 wire, the chart says that
> to keep the sag less than 50 feet, I need 400 pounds
> of tension (as if I could every supply that force!),
> but the recommended #12 tension is only 75 pounds.
Barry,
Have you thought at all about how you are going to feed
the long wire? Very long end-fed wires get very directive
off the ends. We had a 600 footer at Ohio State (up ~100
ft). It ran east-west and worked great toward Africa on 75
meters (it was fed from the West end) - a guaranteed pileup
buster to West Africa on 75 meter SSB. On 40 meters it
didn't seem to work any better than a high dipole. The 2
element quad at 110' feet ran circles around it on 20 meters.
Given the engineering challenge of spanning a 1/2 mile inlet,
have you considered other alternatives. I would certainly
model it before going to that much trouble.
How about a sloping wire from one bluff down into the inlet
at about 45 degrees using a heavy anchor to hold the bottom
end in place? If your primary interest is shooting towards the
saltwater, I would want to be vertically polarized.
73 de Mike, W4EF............................
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