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[TowerTalk] Rotor swap query

To: "towertalk@contesting.com" <towertalk@contesting.com>
Subject: [TowerTalk] Rotor swap query
From: John McCormick via TowerTalk <towertalk@contesting.com>
Reply-to: John McCormick <n0fcd@yahoo.com>
Date: Tue, 18 Nov 2014 02:11:06 +0000 (UTC)
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
It was bound to happen, although I wasn't expecting it so soon. I experienced a 
rotor issue during the Sweepstakes contest last weekend when a visitor was 
operating my station in a multi-operator effort. The Ham IV rotor is still 
working, but the meter dial is stuck at southwest, even when the beam is 
pointed in another direction. A ham buddy who is much more electrically savvy 
helped me do some troubleshooting today and we are pretty convinced that the 
potentiometer up in the rotor is not working properly. We also discovered that 
the previous owner of the control box had removed the fuse that is supposed to 
protect the potentiometer and metering circuitry. 

The good news: I have a spare Ham IV rotor (purchased for this exact kind of 
situation), so I can swap them out an make repairs to the one now up in the 
tower. I also have a spare control box (we tried that as well today and it 
produced the same southwest reading).

The bad news: I've never swapped out the rotor before and I don't have a gin 
pole, something I plan to eventually acquire.

My question: What's the best procedure for swapping out the rotor? Will I be 
able to lift up the mast and beam 18 inches and place it on a wooden brace in 
the tower, while I make the swap, securing the base of the mast with some ropes 
or wires to keep it from moving laterally? Am I foolish to even attempt this 
without a gin pole, helping me lift the weight from the ground?

Some other specifics:

+ US Tower TX-455, with a KF7P work platform installed (cranks down to 22 feet, 
but I don't have the tilt-over fixture at this point)
+ 5-element yagi (57 pounds)
+ WARC rotatable dipole (about 10 pounds)
+ 10-foot mast, 2-inch diameter (25 pounds)
+ one thrust bearing installed at top of tower

Thanks for any thoughts directly or through the list.
73s, John/N0FCD ( N0FCD@yahoo.com )

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