[TowerTalk] Rotor Loop - How to ??

[Dave]

I am in the final planning stages prior to the installation of a 4el SteppIR onto a 70' Trylon self-supporting tower. 
The antenna will be positioned about 3' above the top of the tower.

How do I prepare the coax and control cables for the transition from the rotating antenna to the fixed tower?
Do I fabricate lengths of replaceable cable just for the transition (rotor loop)?
How do I route the cables? Multiple turns loosely around the mast like a spring? Just a single drooping loop?
How long should they be?
Any special coax? The antenna coax fitting is not accessible. Will Bury-Flex provide adequate service?

Cheers,
Dave - N7DRK
Rice, WA