My big fear with a tower such as this is that instead of multiple weak links
(ring rotors), where perhaps one antenna bites it, you have one big weak
link that would make the whole assembly bite it. The other angle that is
perhaps not been explored either is the capacity of the tower to accept
additional loads along its length.
If I recall correctly, the Big Bertha tower worked because the entire tower
base was inserted into the bearings which were held down by lots of concrete
and because the design assumed from the start multiple antennas from top
down.
I also hate to think how much the 'wet-stamp fella' will charge for the
engineering analysis needed for his E&O insurance to cover it, not to
mention the cost of the hardware. He'll need to spec out the steel strength,
the fasteners, the PSI of the concrete, the size of whatever 'plates' are
used, the diameter and wall thickness of any 'posts,' etc., etc.
Not to say that it can't be done, but I think the answer is going to be more
complicated than it appears. I think of all of them, the turntable on
rotating post idea (No. 3) is the most feasible. I think Nos.1 and 2
overlook that on a self-supporter, that 'vertical load' is as much pulling
upward as it is pushing downward.
But before I did anything, I'd talk to a couple of guys offering rotating
tower systems and see what they know: there may be no need to reinvent the
wheel on this one.
73, kelly
ve4xt
----- Original Message -----
From: "Phil Camera" <kb9cry@comcast.net>
To: <TowerTalk@contesting.com>
Sent: Thursday, January 12, 2006 11:08 AM
Subject: [TowerTalk] Making a self-supporting tower rotate
> Why go through the bother of engineering a rotating self supporting tower?
> You are certainly going to have to have a structural engineer bless any
design.
>
> Personally I use a rotator and just turn the antennas. Phil KB9CRY
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