[TowerTalk] 450 ohm feedline and coax

[Jim Lux]

On 12/23/14 11:12 AM, Ken wrote:
> You are right, Jim, wider spacing is REQUIRED.   From the ARRL Antenna Book:
>
> “The line should be kept away from other conductors including downspouts, metal window frames, flashing, etc. by a distance of two to three times the line spacing.”
>
>

The challenge is that there's not a lot of analytical backup in the 
handbook (not that there should be) for that statement. "how much worse 
is it at 2 than at 3"?

I think, though, that at 3 x spacing (based on the algebra in my 
previous post), you're definitely down in the <1% kind of effect.