[RFI] Control cable

[Jim Brown]

On Wed,6/29/2016 8:43 AM, Gary Smith wrote:
> That said, I do think better control wires are needed and I can
> convert the existing CAT6 wires into 4 more radials for 160.

It's always useful to think about the mechanism by which RF induced onto 
those control wires might cause difficulty. They're driving relays, so 
no RF susceptibility there, and you've observed no issues in the control 
electronics that drives them. So -- I wouldn't worry about anything more 
than physical properties and Ohm's law in choosing those cables. And 
since CAT5/6 is working, conductors of modest size appear to be sufficient.

What I WOULD do is choke them well at the frequencies of interest, not 
only in the shack, but at intermediate points, so that they receive and 
re-radiate RF noise. Since they're not carrying TX RF, turns around a 
single toroid or clamp-on should be sufficient.

73, Jim K9YC