[TowerTalk] Antenna 6 feet above the top of an AB-577

[Pete Smith N4ZR]

I am planning to put a 3-element 6-meter yagi 6 feet above a C-3E 
tribander, which in turn is supported by a Yaesu G-1000DXA rotator on 
the top of an AB-577 tower.  An engineer ham friend has raised the 
question about whether one can do this successfully, given the side 
loads that could be applied to the rotator's case by wind, a 6-foot 
lever arm and this small yagi (1.8 square feet of wind area in a pretty 
sheltered location).

Yaesu, characteristically, shies away in horror from any such thing - 
the manual recommends only using the rotator *inside* a tower, with a 
thrust bearing above it to carry mast loading.  On the other hand, my 
C-3E has survived 5 years mounted on top of the AB-577.  Their manual 
writers are extraordinarily conservative, so I'm asking for real-world 
experience. Have you mounted a small yagi like this above a G-1000DXA, 
and if so, what and how far above?

-- 
73, Pete N4ZR