[TowerTalk] 450 ohm feedline and coax

[Ken]

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.”

Ken WA8JXM

> On Dec 23, 2014, at 12:16 PM, Jim Brown <jim at audiosystemsgroup.com> wrote:
> 
> On Tue,12/23/2014 9:07 AM, Tom Osborne wrote:
>> HI All
>> 
>> I've seen that you should keep the 450 ohm twinlead at leas the width of the cable away from anything metallic. Does that include coax cable? 
> 
> YES! And although I haven't seen any math to support it, I'd want wider spacing than that.
> 
>> I want to run some twinlead out to an antenna and where it would come into the shack is a coax cable and it would be laying right on top of it.
>> 
>> Just wonder it that would cause any problems. 
> 
> Yes, it could cause problems.