FWIW...
I have the junior version G1000SDX rotator. I have a 2" diameter (1/4"
wall) aluminum mast, 20 feet long. Ten feet is in the tower, ten feet
sticking out. A TH-11DX is one foot above the apex (that has a thrust
bearing), a 5-element 6m Cushcraft five feet above that, and a 17'
Diamond 144/440 MHz vertical at the top. This is all held up on a 70'
Universal self supporting aluminum tower (picture on QRZ - a 40m dipole
is side mounted to the tower and does not turn with the mast).
I did not pin the mast. I was very careful to torque the U-bolts evenly
as I tightened up the clam shell. Be aware you can easily snap those
U-bots if you "strong arm" the tightening process. You also need to be
careful to center the mast with the centerline of the rotator. Don't
just "slap" these parts together!
My array has stayed in place for a decade or more. With that long mast
(11 feet separating the rotator from the TH-11DX) and the flexibility of
the tower, these apparently absorb the torsion that develops in the
wind/rain storms. At least that's my non-engineered thinking on the topic.
In the long run, I would rather the antenna slip on the mast than tear
out the rotator drive train if something "must give" in the wind.
73 de Bob - KØRC in MN
------------------------------------------------------------------------
On 3/27/2015 7:08 PM, David Robbins wrote:
I have never put the bolt through the mast. I have had some big antennas
slip in high winds but nothing has broken.
David Robbins K1TTT
e-mail: mailto:k1ttt@arrl.net
web: http://wiki.k1ttt.net
AR-Cluster node: 145.69MHz or telnet://k1ttt.net
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of Steve
K7AWB
Sent: Friday, March 27, 2015 23:47
To: towertalk@contesting.com
Subject: [TowerTalk] yaesu rotator and aluminum mast
I have a new Yaesu rotator model G-2800DXA which I will put in my Rohn 25
tower
in a month or two. The rotator comes with a pin to put through the mast (by
drilling out a hole through the mast). I know that would work in steel
masts, but do you think the aluminum is too soft to use that requirement so
should I not or should I do it?
I am looking for anyone who actually had to make that same decision and
their consequences, if any.
73
Steve Sala
K7AWB
DN17es
Nine Mile Falls, WA
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