The un-guyed aluminum Cushcraft will bend and break long
before that ridge beam will.
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com]On Behalf Of
Michael Tope
Sent: Saturday, March 13, 2004 6:35 PM
To: TowerTalk
Subject: [TowerTalk] Mounting a Cushcraft R8
I am getting ready to install some kind of multiband
vertical
at the QTH of a bed ridden friend, so he can hopefully get
on HF during his extended convalescence. Last week I
stopped by his QTH just to look things over. His house is
a 2-story with a large ~(6" x 10") ridge-beam running along
the peak of the roof from one end of the house to the other.
The ridge beam sticks out about two feet from either gable,
so we were thinking that this might be a convenient mounting
point attaching the base of a multiband vertical.
My question is, will I be asking too much from this beam
if I try mounting a Cushcraft R8 off the end of it without
any guy wires? The Cushcraft R8 is 28' tall, and based
on my quick and dirty back-of-envelope calculations,
it would generate around 800 ft-lbs of overturning
moment in an 80 MPH wind (the rated wind speed of the
R8). I think I can come up with a suitable bracket that
will distribute the load from the base of the vertical
evenly
across the exposed surface area of the ridge beam, such
that the base of the vertical and the beam will form a
fairly
rigid assembly. I am mostly worried about twisting of the
beam when the wind is blowing perpendicular to its
axis. Any thoughts from the group?
Thanks,
Mike, W4EF............
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting
Towers", "Wireless Weather Stations", and lot's more. Call
Toll Free, 1-800-333-9041 with any questions and ask for
Sherman, W2FLA.
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_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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