I have a 40m wire yagi with six rope attachment points, five of which
are in trees. The wire and ropes broke often, usually right before a
contest or major DXpedition. With a house plus other trees beneath it,
repairs were often a snarled mess. There had to be a better way.
Several years ago I started using the rope anchoring method pictured in
the photos at the link below. There is a continuous loop to a pulley at
the top in each tree. The antenna rope is attached to the loop via a
third pulley, which provides even more flexibility. The springs are
strong enough to hold the antenna in shape, but have enough stretch to
survive wind storms. The ropes ride effortlessly along the pulleys.
No repairs have been necessary since using this system. All of the
hardware is available from Harbor Freight or Tractor Supply. The expense
was well worth it to me, as it's has eliminated many hours of
frustrating repair work every season.
http://k4ro.net/Tree_Anchors/
Kirk K4RO
On 1/31/2015 9:56 AM, K7LXC--- via TowerTalk wrote:
My wires are up 130 ft in redwoods, so they need pretty robust rigging
hardware. Not everyone needs stuff this robust. :) Another important
rigging element for any wire in a tree is a weight below a pulley
terminating one end of the antenna to provide some "give" for tree sway.
There are many ways to skin this cat, including old window weights and
cement in a bucket. I use big water jugs that I fill with dry sand. I'm
typically using 70-90 pounds of tension.
Another point. Make the dipole halyard (haul rope) a continuous loop.
Put a knot in the line and attach the antenna wire to it. That way if the
wire breaks, you won't have to climb up to the top of the rope to retrieve
it. In my experience it's almost always the wire that breaks - not the
halyard.
Cheers,
Steve K7LXC
TOWER TECH
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