I have never done a crane install so I will let others speak to that.
For Tram of a 70 ft tower, you have 2 choices from my experience. Tram to
the point on the mast above the tower (say 73') and have a backstay; or tram
to the top of the tower itself, attach the beam to the tower, then lift the
antenna up the last few feet to the mast position.
The tram should be about 100 ft out from the tower. The back stay can be
closer but still likely around guy wire length - 60 ft or so. If you have
the room, it's the easiest.
What I have learned over time is the advantage of having the top set of guys
NOT be at the top of the tower but actually a few feet below the tower.
Makes tramming up big yagis A LOT easier.
I have trammed up myself but find that a crew of 3 is a good minimum. A
hauler and 2 "steerers" and then as the antenna gets to the top, one of the
steerers becomes the climber. 4 people is better but you do what you have
to.
The steerers are also "anti flippers" if the tag lines are positioned right.
Its an art form to have the tag lines all releasable after the yagi is in
place - but I digress.
Ed N1UR
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