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Author Topic: How to drop down ends of 80meter dipole  (Read 899 times)
N7GCO
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Posts: 144




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« on: August 04, 2012, 12:48:49 PM »

I am installing an 80 meter dipole between two tall trees. The trees are 100 feet apart. I understand I can drop the ends of the dipole down without much loss. How do you do that? I will be anchoring the dipole to the trees. How to you attach the anchor and keep the end free to drop down? A number of authors say you can do it, but I have seen no diagrams or photos of how they handle the anchor points.

Thanks for advice
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WB6BYU
Member

Posts: 13287




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« Reply #1 on: August 04, 2012, 01:37:35 PM »

What I do is tie the insulators to the wires in from the ends.  The insulators then are
tied off with ropes while the end of the wires hang downwards.  You can put insulators
on the very ends and tie them of with strings to keep them from blowing around if you
want.

So, if you have a 130' dipole, I'd probably leave 20' hanging down from each end, for
a total length between insulators of 90 feet.  A rope on each insulator would then
tie off to the halyard on each end.  Ropes on the ends of the hanging sections would
keep them from blowing around, and might be used to bend them into a Z or other
convenient shape as needed.


To tie off to a tree, I'll mount a pulley in the tree with a halyard that comes down to
ground level.  I use the halyard to pull up the antenna, then put a counterweight on
the bottom so that, when the trees blow in the wind, the stress raises the weight
rather than pulling the antenna apart.

For temporary operation I'd just toss a rope over the tree and tie it off to a flexible
branch that can bend with the wind.
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W9GB
Member

Posts: 2623




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« Reply #2 on: August 04, 2012, 01:38:49 PM »

You run a "clothes-line" (or messenger) wire or rope between the trees -- at desired top height of center insulator for this antenna.

The center insulator for your 80-meter dipole has a hook or eye-bolt at top.
That is where this support messenger wire attaches.

SO, then you separately raise or attach the ends of the dipole for desired inverted-V angle.
You can use halyards, pulleys and opens -- at additional $ ... IF you desire to raise and lower the antenna (THINK -- Sail boat rigging).

w9gb
« Last Edit: August 04, 2012, 01:42:00 PM by W9GB » Logged
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