[TowerTalk] boom-to-mast slippage

[MAERTZ, A REID]

Greetings:

Although the situation I'm going to describe exists in a vhf/uhf
application, but I believe it has HF applications also.

Situation:  I have a pair of M^2 yagis on a KLM fiberglass crossboom
(for elevation control).  The 2M boom is about 18 feet long, the 70 cm
is about 9 feet long. I am unable to tighten the 2M U bolts to the
fiberglass cross boom enough to prevent it from slipping and thus
rotating (in the vertical plane) to where the two yagis are no longer
parallel. 

I reinforced the fiberglass boom by inserting a small section of wooden
dowel into the boom at the point where the U bolts clamp to allow me to
apply more torque.  That reduced the slippage, but hasn't prevented it.
I'm concerned that applying much more torque to the U bolts will
break/crack the fiberglass.  

Is there another alternative available that would eliminate this
slippage at the boom that's been applied by some of you with the VERY
long element HF antennas?  I realize you aren't elevating them and
they're balanced on the boom for the most part, but there are still
those unbalanced vertical forces that you had to compensate for to
eliminate this type of slippage

Thanks in advance for any suggestions you can provide!

73, Reid
W0FVR

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