[TowerTalk] Coax, conduit and toroids

[Steve Hunt]

Jim,

I'm not going to waste my time in long debate with you again!

I'll just leave other readers to check what I have said using NEC. You 
might believe that NEC can't model the common-mode currents, but that's 
the first time I've heard that claimed, and there are plenty of other 
well-respected folk - Roy Lewallen, VK1OD and W8JI for example - who I 
expect would disagree with you. Look at Tom's website and you'll see how 
he uses EZNEC to model common-mode situations.

I encourage other readers not to believe me or Jim but to check it for 
themselves; model a simple coax-fed symmetrical dipole and see if Jims 
claim that "a perfectly balanced antenna system must have zero voltage 
across the choke and zero current through it" holds up.

And remember, if the choke has zero voltage across it and zero current 
through it, you can safely remove it and nothing will change :)

Steve G3TXQ