>NOTE: The usual rotor plate does not have a magical 2+ inch hole where
>you want it so the mast can easily pass through it during antenna
>servicing... of course...
Every rotor plate that I have ever seen does... Even the ones on the Rohn 25
G.
I'm going to have the same issue installing my mast into my new Rohn 45.
It's one of the HD ones 1/4" wall and 20+ feet long. I'm going to
install the 2L 40 at the top and pull it on up.....
The last tower I had was a 25G and used Sched 80 black pipe. I used a
come-along to putt it up. Made a low profile hook/bracket that
would allow the cable and the mast to slide through the rotor plate. Worked
fine. As you recall, the rotor plate has a
cutout for the screw terminals. Just thread the come-along cable through
that and put a piece of rubber tubing over the edge to
keep the plate from gouging and ripping the cable.
73 and let us know how you did...
Jim W7RY
>GL
>Jim, K4OJ
I'm going
----- Original Message -----
From: "Jim White, K4OJ" <k4oj@tampabay.rr.com>
To: "Bob Gates" <regates@kingwoodcable.com>
Cc: "Tower Talk" <towertalk@contesting.com>
Sent: Sunday, September 14, 2003 6:28 PM
Subject: Re: [TowerTalk] Lowering mast on fixed tower
> Hi Bob...
>
> Dear Santa - All I want for Christmas is servicing of my HF Christmas
Tree!
>
> Stacked yagis are rough...
>
> Unless you have a very very heavy duty mast with multiple thrust
> bearings, etc. climbing of the mast with ladder steps is not an option
> so, you have to lower it into the tower...
>
> The lower antennas have to either be slid up or removed to get at the
> top one... yes, it is a lot of work...
>
> The biggest bummer of this type of installation usually is that the tape
> that holds the top feedline to the boom and the mast that will fail over
> time and suddenly you have a dangling mess which is, of course, out of
> reach...
>
> There was a great article in NCJ an issue or two ago by Robin Midgett
> KB4?... he developed a cable and pulley system that allows the mast to
> be lowered and re-raised very smoothly - it is a massive system but
> suspect that it is one of those things that you are really glad you have
> if you need to use it!
>
> A come along is the usual method of raising and lowering of the mast - a
> secure attachment to the mast for a grab point is mandatory - typically
> pieces of lumber or angle will be placed across horizontal rungs to
> support the weight of the mast and antennas when the mast passes below
> the rotor plate...
>
> NOTE: The usual rotor plate does not have a magical 2+ inch hole where
> you want it so the mast can easily pass through it during antenna
> servicing... of course...
>
> GL
>
> Jim, K4OJ
>
>
>
>
> Bob Gates wrote:
> > Please excuse what, for most, is probably an elementary question. But I
feel
> > like Rip van Winkle, coming back into the hobby at such a late date. I
have a
> > question that I cannot figure out the solution to in my mind. Assume a
fixed
> > height tower, say Rohn 45G. Assume a rotor mounted to an accessory
plate 5'
> > below the top, with a 20' heavy duty mast extending up through the
tower, Then
> > assume a yagi installed 10'-12' above the top of the tower. How does
one
> > perform maintenance on this antenna? I assume you would need some means
to
> > remove the rotor and lower the mast down through the tower. After work
is
> > completed, you would then need to raise the mast back up to the desired
height
> > and reinstall the rotor. The problem is increased if there is another
antenna
> > installed on the mast, say 1' above the top of the tower. Obviously you
could
> > hire a crane at a gazillion dollars per hour to pick up the assembly and
set it
> > on the ground. But how would you do it without one? Realistically, can
you
> > climb up the mast to work on the top antenna?
> > Thanks in advance,
> >
> > Bob KG7KW
> > _______________________________________________
> >
> > 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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