[TowerTalk] Need dimensions of Gamma match for 80 & 160

[VeeAthreePL]

It was written somewhere on this reflector but I cant seems to find it.
I try to use my crank up tower TX455 (extend to 55 feet - 3 section about 
20 feet long each) for 80 & 160.
I heared that some of you use it successfully on 80 & 160.
Is the Gamma mach attached to the top of the middle section or to the top 
of the bottom section? What is the spacing between tower and wire? Is 12 
inch good enough or I have to go to 16 inch? Is the size 12 wire good 
enough or I have to use 1/2" tubing?
Thanks
Andy - VA3PL