I have had a tree mounted small tribander for about 10 years.
Initially I had topped the tree, about a 40 ft cedar tree due to the top
turning brown and dead. Best advice was to top it and see if it survived.
It did and then I got the idea of tree mounting the yagi. This tree was
pretty easy to climb with branches starting about 10 ft off the ground and
pretty well spaced for climbing.
I built an angle iron frame that held a Ham-M rotator on the bottom and a
thrust bearing at the top. Similiar to the VE7GKH illustration. Somewhat
the same as the Hazer carrier. This was bolted to the tree with all thread
rod. one at the top and one at the bottom of the frame. Its been there
and solid for about 10 years. The branches at the top level of the tree do
grow up and interfere with the yagi rotation from time to time and require
trimming them back down.
The antenna is an A3S about 3 feet above the thrust bearing. The mast is
2" EMT tubing (Steve , please don't kick me off TT for this terrible breach
of engineering, its worked fine so far)
I am planning to do this again at a different location although it will be
tougher in that tree.
73 Jim KI7Y
|