[UK-CONTEST] rotating guy rings

[Dave Lawley]

Hi Steve

To make our poles easier to rotate (armstrong method) on VHF FD we use a 
steel ring above the scaffold clamp, then a PTFE ring, then on top of 
that the 6 inch square plate carrying the guys.

However, there can be quite a lot of friction and you could be stressing 
the rotator quite a bit. It will be important to get the mast as 
straight as you possibly can, which may mean turnbuckles at the guy 
stakes for fine adjustment. If the wind blows hard, there will be more 
friction.

Putting the rotator at the bottom of a fixed lattice tower can be a good 
idea for maintenance purposes and to take out some of the torque due to 
windage on the antennas. But for a 50ft scaffold mast erected from time 
to time I reckon the best place for the rotator is up top.

For G1A last October I put up a 3el tribander plus G600 rotator at 50ft 
on a sloping site single-handed. The key is to use a sufficiently long 
gin pole (I used 18ft made of two 9ft scaffold tubes) and a block and 
tackle. I used two 2-blocks, with the right size rope for the sheaves, 
important to minimise friction. The other thing to remember is to make 
the top guy to the gin much tighter than the others, this puts an upward 
bend in the mast which compensates for the extra weight at the top.

While I'm on the subject, be very wary of the J-beam scaffold couplers. 
Some of them don't do up tightly enough around a scaffold pole which as 
you may know is not 2inch diameter but something like 1 29/32 inch. We 
always use external scaffold couplers which are only half the length but 
much stronger.

Dave G4BUO