Dave:
You're correct - to a point. The knot/shackle at the bottom of the CM
(or any other) mast does not have to thread through either/any bearings.
Once past the rotator plate level, the mast is as high as it ever needs to
go with this approach. That much I'll agree with.
However, with the Trylon bearing/rotator plates, there is a 2-3/8 inch
hole factory-drilled in the center of each. One could delay installing this
plate for the rotator until the mast is above that level, but you can't rely
on the plate as a rest spot for the mast - there's a hole in the plate.
Also (and I just thought of this with this posting), I would not feel
all that comfortable with this heavy mast hanging by a couple of muffler
clamps above my hands while I'm installing the rotator plate just below it.
Especially with the added weight of the full antenna complement attached to
the mast by this time. At the time of my tower work, I had installed all
three plates (two bearing and one rotator) before we hauled up the mast.
Machts nichts, I suppose.
73 de
Gene Smar AD3F
----- Original Message -----
From: "David Robbins K1TTT" <k1ttt@arrl.net>
To: <towertalk@contesting.com>
Sent: Tuesday, June 07, 2005 5:30 PM
Subject: Re: [TowerTalk] installing monster masts in towers
> Actually... the knot/shackle or a through-bolt doesn't matter at the
bottom
> of the mast. Only the top of the mast has to fit through the bearing(s)
or
> top tube. Raise the mast up to near its final position and then put the
> rotor shelf under it and you never have to worry about the size of the
> bottom hardware. The way I did a 20' mast on rohn 45 I only pulled it up
> until just the top was through the tube, then clamped it and removed the
gin
> pole rope. The first antenna was clamped on and then the mast was raised
> from there by lifting with a come-a-long hooked to the bottom of the mast
> inside the tower.... jack it up 5', add another antenna, jack it up again,
> add another one... then put in rotor plate and rotor under the mast.
>
>
> David Robbins K1TTT
> e-mail: mailto:k1ttt@arrl.net
> web: http://www.k1ttt.net
> AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net
>
>
> > -----Original Message-----
> > From: towertalk-bounces@contesting.com [mailto:towertalk-
> > bounces@contesting.com] On Behalf Of ersmar@comcast.net
> > Sent: Tuesday, June 07, 2005 20:44
> > To: JC Smith; towertalk@contesting.com
> > Subject: Re: [TowerTalk] installing monster masts in towers
> >
> > JC et al:
> >
> > Sorry. Only the KNOT should fit into the bottom of the CM mast.
The
> > shackle should be large enough to keep the knot from sliding farther
> > inside the mast, but small enough to fit through the holes in the
> > shelves/bearings. Due to some incomplete editing of my original
posting,
> > it appeared as though the knot AND shackle should fit into the mast.
> > Obviously a bad thing.
> >
> > 73 de
> > Gene Smar AD3F
> >
> >
> >
> > > JC:
> > >
> > > You've got it: Build the Trylon or ANW tower AROUND the CM mast.
> > > Seriously. It's what I did, although a bit belatedly. (See below.)
> > >
> > > After you have the first/bottom section built and concreted into
> > place
> > > (allow for a week or so of curing), remove all the braces on one side
of
> > the
> > > lone tower section. Then you can lean the CM mast against the inside
of
> > the
> > > tower and reassemble the braces. Once the CM is inside the base, you
> > can
> > > continue having fun with your erector set in the back yard and finish
> > the
> > > construction.
> > >
> > > After the tower is completed, you'll need a ginpole at the top.
> > Feed the
> > > haul line from the ginpole down through the bearing(s) and the rotator
> > plates
> > > and thread it throught the CM mast from the top. Securely tie the end
> > of the
> > > haul rope onto a shackle that will rest against the bottom of the mast
> > while
> > > hauling it up through the two or three shelves. This means that the
> > knot and
> > > shackle must be small enough to fit into the mast and the shackle
small
> > enough
> > > to slide through the openings in the plates and bearings.
> > >
> > > Once the mast emerges from atop the tower, lock it temporarily
into
> > place
> > > with something - I used two pair of back-to-back muffler clamps around
> > the mast
> > > and resting on the top and middle bearings. With the clamps securely
> > holding
> > > the mast in place, remove the haul rope and use a come-along to lift
the
> > mast,
> > > plus antennas, into their final positions.
> > >
> > > I didn't run across this idea (courtesy of N3RR) until the tower
> > was
> > > completely built. I had the delicate task of leaning the CM against
the
> > bottom
> > > section of the finished tower and removing one brace at a time from
the
> > side of
> > > three lowest sections as I allowed the mast to tip backwards into the
> > center of
> > > the tower. I removed one brace at a time, then replaced it, to ensure
I
> > didn't
> > > remove too much of the structural components of the finished tower at
a
> > time.
> > >
> > > CAREFUL: If you completely build the tower first as I did, be
sure
> > the CM
> > > mast is securely tied onto the tower while you are letting it slide
into
> > > position inside the tower. A better (and safer) approach would be to
> > encase the
> > > CM mast inside the tower after the first section has been concreted.
> > >
> > > 73 de
> > > Gene Smar AD3F
> > >
> > >
> > >
> > > > OK, so lets say I've got my new, super HD, 70', freestanding, Trylon
> > or AN
> > > > Wireless tower up in place. Now I've got to get that 24'
Chrom-Moly
> > mast
> > > > up there and through the thrust bearing somehow. How the heck do
you
> > do
> > > > that (no cranes allowed, it looks like I'm going to have to stick
> > build the
> > > > tower)? The antennas I can tram up on temporary guy wires, but even
> > if I
> > > > could do that with the mast I've still got to stand it up to get it
> > through
> > > > the center of the tower. Big gin pole? Seems like you'd need a gin
> > pole to
> > > > raise a gin pole big enough to handle one of those monster masts.
> > > > Helocopter? Maybe... gee, might as well have them pick up the tower
> > as
> > > > well, but how much does that cost? Anyone have experience with that
> > and can
> > > > give me a ballpark number? It's gotta be big bucks, and doing it
over
> > a
> > > > residential neighborhood? Maybe not even possible. So, how the
heck
> > do you
> > > > do that? Build the tower around the mast and pull it straight up
the
> > > > middle? Any other suggestions?
> > > > Thanks & 73 - JC, k0hps@amsat.org
> > > >
> > > >
> > > >
> > > > _______________________________________________
> > > >
> > > > 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.
> > > >
> > > > _______________________________________________
> > > > TowerTalk mailing list
> > > > TowerTalk@contesting.com
> > > > http://lists.contesting.com/mailman/listinfo/towertalk
> > > _______________________________________________
> > >
> > > 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.
> > >
> > > _______________________________________________
> > > TowerTalk mailing list
> > > TowerTalk@contesting.com
> > > http://lists.contesting.com/mailman/listinfo/towertalk
> > _______________________________________________
> >
> > 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.
> >
> > _______________________________________________
> > TowerTalk mailing list
> > TowerTalk@contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
>
> _______________________________________________
>
> 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.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
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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