On Jul 2, 9:33 am, John Smith wrote:
K7ITM wrote:
...
The only way to keep a wire--e.g., piece of coax--from being a
radiator is to keep net current at zero. If there's no net current,
you didn't need the wire anyway (at that frequency, at least). If
it's a protective ground for mains frequency, it will probably still
work for that purpose if you add ferrite for RF choking.

K7ITM:

I was hoping the rf/dc/ac could reach ground via a very low
resistance/impedance to rf on the inner surface of the braid and the
center conductor ...

While it would be virtually impossible to reduce rf on the outer braid
to absolute zero, I was hoping the choke would provide sufficient
impedance to rf to where it became near negligible, at least for
practical purposes.

Regards,
JS

If there's a net RF current, there's a net RF current, and it will
radiate. It matters not a whit whether you say the net is on the
inside or the outside or distributed between them in any proportion.
If you choke things so there's no net current, you may as well not
have bothered putting the wire/coax/whatever in to begin with.
Consider what the current on the inside of the outer conductor must be
if the coax is acting as a transmission line, and consider where that
current goes at the "top" end of the piece you suggest.

To keep RF "out of the shack," put a Faraday cage around the shack and
don't turn RF loose inside that cage. Then it doesn't matter (with
respect to RF "in the shack") whether the Faraday cage is connected to
"ground" or not.

What exactly is "ground," anyway? Do you think it has magical
properties? What ARE its properties? What does it do for you?