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[Towertalk] tower mast = to pin OR not to pin

To: <towertalk@contesting.com>
Subject: [Towertalk] tower mast = to pin OR not to pin
From: n4zr@contesting.com (Pete Smith)
Date: Mon, 18 Nov 2002 12:09:57 -0500
At 11:24 AM 11/18/02 -0500, K7LXC@aol.com wrote:
>Now with the M2 Orion rotator and the Yaesus though I've started to pin
>them. I have about 100% mast slippage with Orion rotors over a year's time
>and started pinning them in self-defense. Since it has a nice worm-gear
>arrangement, there's not much that'll break from wind-induced torque. The
>problem with the Yaesu's is that they're tough to get tight enough without
>breaking the mast clamp.


Recent production Yaesu rotators include a slip sheet in the manual about 
how to avoid this.  It's a variation on the old Hy-Gain tightening sequence 
trick -- first tighten the mast clamps on the mast, then tighten the clamps 
to the rotator top (making sure they are symmetrically placed on the 
rotator top, which has a graduated scale on it to assist), and finally 
tighten the rotator to the shelf.

I'd be willing to bet that 95 percent of broken clamps on Yaesu rotators 
result from working in the opposite direction.  Cast aluminum clamps don't 
like to be bent, but will handle a lot in compression with appropriate 
bolts and washers.

My Yaesu rotators are both pinned.

73, Pete N4ZR
Sometimes a tower is just a tower





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