[TowerTalk] Coax/Rotor Cable on the outside or inside of the tower

[Jim Brown]

On 3/28/2012 5:05 PM, Richard Thorne wrote:
> I don't plan on using the tower as a loaded vertical on 160 but I would
> at least like to keep the option open.  With that in mind does it matter
> if run the coax and rotor lines up the inside or up the outside of the
> tower.

Inside the tower is much better. When you load the tower, skin effect 
causes RF current to flow mostly on the outside of the tower. The coax 
shield should be bonded to the tower top and bottom for lightning 
protection, and both cables should have serious ferrite chokes at the 
base of the tower, using the winding guidelines in 
http://audiosystemsgroup.com/RFI-Ham.pdf   The chokes are important only 
if the tower is being loaded.

73, Jim K9YC