Hi Steve,
I did not personally see the failed 2800 rotators, but my recollection is that
the case failed.
73!
Frank
W3LPL
---- Original message ----
>Date: Tue, 24 Apr 2007 12:35:34 EDT
>From: K7LXC@aol.com
>Subject: Re: [TowerTalk] Mast slipping
>To: towertalk@contesting.com, donovanf@starpower.net
>
> In a message dated 4/22/2007 9:15:57 P.M. Pacific Daylight
> Time, towertalk-request@contesting.com writes:
>
> > I don't think the problem is a design flaw with the 2800,
> I believe it not rated for very large 3 element 40 meter
> full sized Yagis (including
> the SteppIR MonstIR) in strong winds.
>
> > Orion 2800 rotators failed catastrophically in three
> different installations in my local area when used with very
> large antennas
> (full size 3 element 40M Yagis and SteppIR MonstIRs). In
> each case it
> was a result of 40-50 MPH winds typical for this area. Each
> failure
> occured soon after installation of the rotator.
>
> Were the failures in the transmission or what? While I'm
> sure it happens, I haven't personally been involved with an
> Orion failure. And yes, they're not a prop pitch but better
> than most other rotators available.
>
> > "Square feet" is an inadequate rating for rotator
> capacity. Very large
> antennas distribute wind loads over a large structure, and
> considerable
> energy is stored in the flexing of very long elements in the
> wind. This
> stored energy creates heavy torque loads that overload all
> but the strongest rotators.
>
> Quite true which is why Hy-Gain and Yaesu both went to
> Effective Moment and K-Factor which are both the antenna
> weight times turning radius - a much more realistic
> measurement.
>
> Cheers,
> Steve K7LXC
> TOWER TECH
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