[TowerTalk] RF Choke or Balun

[wb5oxq]

If I were to make a new choke for my triband beam out of RG-213, how many 
turns would you suggest and what diameter coil.  Is pvc pipe a good coil 
form?  How far away from the connection at the driven element can it be 
located.  Can I tie strap the assembly to the boom?  My antenna is a force 
12 c-3 at 52' above ground.  My current choke may have been hit by lightning 
at some time and works ok at 100 watts with 1.4 to 1 but at legal limit the 
reflected power rises to 70%.
WB5OXQ, Jim in Waco