[Towertalk] Crankup Tubular "Towers"

[Bob Nielsen]

When I lived in the Los Angeles area, we had a club at work which put
up a 40 ft tubular tower with a HAM-3(?) rotator and TH6DXX (also a
ringo ranger 5 ft above the yagi).  The tower was roof-mounted at ~60
ft above ground (which probably increased the wind exposure) and
bracketed at the 12 ft level to a roofhouse.  With just two sections,
it didn't appear to sway all that much, but after several years (and
the worst windstorms I ever experienced in the area) the upper section
of the tower had a permanent bow of a few inches, which prevented it
from retracting more than a few feet.

The lower bracket of the rotator cracked during the 1994 earthquake, but
the tower wasn't noticeably affected (the building had to be
demolished).

73, 
Bob, N7XY

On Fri, Oct 04, 2002 at 11:36:55AM -0400, Dick Green wrote:
> I believe the windload rating is 10 sq ft at 50 MPH. What kind of antenna
> will you be putting on the tower and what's the windload?
> 
> My experience with the 72' version (the MA-770) is that when the windload is
> near the maximum, the fully extended tower sways dramatically in even a
> 15-20 MPH wind. It helps a lot to lower it 10 feet or so. It's better with a
> smaller windload, but still sways uncomfortably for me.
> 
> 73, Dick WC1M
> 
> > -----Original Message-----
> > From: towertalk-admin@contesting.com
> > [mailto:towertalk-admin@contesting.com]On Behalf Of John von Gonten
> > Sent: Tuesday, October 01, 2002 4:57 PM
> > To: towertalk@contesting.com
> > Subject: [Towertalk] Crankup Tubular "Towers"
> >
> >
> > I have been considering the US Tower MA-40 or MA-550 crankup tubular
> > tower as they call them, closer to a tubular crankup mast IMHO.
> >
> > has anyone had any dealing with these in real world situations, these
> > are the 40' and 55' models.  Are they worth the money? Do the really
> > perform well in a sometimes windy area.
> >
> > I live in North Central / North East Texas.  D/FW to be specific.
> >
> > I have a small lot to deal with and do not really have room for much int
> > eh backyard and will not put anything in the front due to neighborhood
> > hoodlums.
> >
> > Any and all input will be greatly appreciated.
> >
> >
> > --
> > 73
> >
> > ------------------------------------------------------------------------
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