At 09:14 PM 12/18/01 -0800, Mike wrote:
>
>Yes, the drivetrain disks work because they use staggered
>bolt patterns each with 4 metal sleeves buried in the rubber
>disk. This allows the bolts to be tightened down hard
>metal to metal with no sloppy rubber in between the bolt
>head and the mating surface.
>
>In order to install a rotator with rubber shock mounts between
>the base and the mounting, a similar scheme that allowed
>for hard mounting of the bolts metal-to-metal would be
>required.
Hi Mike et al. Yaesu apparently makes a device that does exactly what Mike
suggests. See this dated December 2000 from N7US:
"Has anyone used one of these things [Yaesu GA-3000 tower absorber] and, if
so, what do you think?? They are shown on p. 141 of the Fall/Winter AES
catalog. It looks to me to be a two-plate sandwich with big rubber
grommets/bumpers in between. I'm assuming it mounts below a rotor to
minimize the torque on a tower."
In a reply, Mike recounted his experience with a Mercedes drivetrain disk
as a mast absorber, which needed jam nuts added to make it hold together -
simple lockwashers weren't sufficient over time.
I guess I'm not persuaded by the idea that using any such device is just to
make up for marginal mechanical design. After all, the natural environment
provides all kinds of uncommon load events -- the 100-year flood, the freak
windstorm, etc. -- and making provision for such things isn't a bad idea,
even if all normal loads are well within spec.
This is not to endorse the original Hints and Kinks idea, which I never
saw.
73, Pete N4ZR
www.qsl.net/n4zr
AN Wireless Self Supporting Towers are now available! Windloading tables,
foundation diagrams and charts, along with full details are now at the
AN Wireless Web site: http://www.ANWireless.com
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