On Sat, Apr 4, 2009 at 3:55 PM, Jim Brown <firstname.lastname@example.org>wrote:
> Martin Ewing wrote:
> > Yes, but... It's still worth trying to establish a local RF "ground" --
> > ensuring that everything in your shack is bonded together. No antenna
> > system is perfect, and many of us have some RF in our shacks.
> > the same bonding is needed for lightning and AC safety reasons, although
> > inductance is not a worry at 60 Hz.
> > The ideal is a Faraday Cage - enclosing your shack in a (nearly) solid
> > conducting box.
> But a Faraday cage is NOT a solution to the fundamental problem -- RF
> CURRENT flowing where we don't want it. A Faraday cage addresses the E
> field (capacitive coupling) and poor shielding. The E-field is rarely an
> issue with ham gear.
> The E-field and poor shielding IS a common problem with consumer gear,
> but usually 10-20dB less problematic than pin 1 problems excited by RF
> current. If you're going to build a Faraday cage, build it in your
> living room or office where your computers are, not your ham shack. :)
> Jim Brown K9YC
If you're in a Faraday Cage, you are not sensitive to currents flowing on
the outside, which is where any unbalanced antenna currents should go -
assuming no "pin 1" issues. It doesn't help the antenna system, but it
keeps you from getting RF burns.
A real FC is beyond most of us, so this is mainly a theoretical point.
73 Martin AA6E
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