In a typical installation for an OCF antenna, I'd think a concrete block
in a bucket should be more than adequate. Be careful not to exceed the
ratings of the antenna or tower. I agree with David on just using the
weight at the tree, but here (central Lower Michigan), I'd use a lot
more weight because of common spring ice storms
In my case I have a similar arrangement, but it's a center fed, sloping,
half wave dipole with one end to the tower and the lower end to a
"substantial" tree. I use a relatively strong braided Dacron rope
(available from Davis RF and other sources). I depend on the elasticity
of the rope, but it's under "roughly" 200# of tension. To eliminate
center sag from the coax and choke weight. At this tension there is only
a slight visible sag, sighting along the length of the antenna from the
lower end. With SW antenna the rope runs through a half inch hose
around the back side of the tree. The hose is to protect the tree, The
NE antenna ties off to a forged lag bolt with an eye, in a very large
tree. At this size there is little danger of the mature tree growing
around the lag bolt. A younger tree might require moving the bolt every
few years.
I use as much tension as desired within the strength capabilities of the
antenna and supports.
As a personal preference I'd use at least 100#, with the tower back
guyed ( if necessary) With my 45G, the antennas serve as tension
against each other. OTOH. My 100' tower's guying is strong enough that
back guying would not be needed even at 200# tension in just one direction.
73
Roger (K8RI)
On 8/11/2016 Thursday 12:20 PM, David Robbins wrote:
Enough weight to keep it reasonably tight. Normally only one end needs to
be able to move, I would do that on the tree end instead of the tower.
typical weights I have seen are buckets filled with concrete or rocks or
sand, 20-30 pounds at most... if it is very long then maybe more weight.
David Robbins K1TTT
e-mail: mailto:k1ttt@arrl.net
web: http://wiki.k1ttt.net
AR-Cluster node: 145.69MHz or telnet://k1ttt.net:7373
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of Chuck
Gooden
Sent: Thursday, August 11, 2016 16:14
To: towertalk@contesting.com
Subject: [TowerTalk] Weight on ends of a OCF diploe
Retired recently and am getting back into ham radion.
I am planning on putting up a 80 to 10 meter OCF antenna. The antenna will
be supported on a TV tower with the ends attached to some pine trees. I am
planning on using a pulley and some weight on the ends to allow for wind
effects on the pine trees.
My question is how much weight will I need at the ends to allow for wind
movement of the trees?
Thanks,
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73
Roger (K8RI)
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