At 01:51 PM 10/13/2005, monty taylor wrote:
>As a result I will RF ground outside my
>windows today as I already have the 8 foot rod ready to go.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
I shake my head whenever I hear the term "RF ground" in the sense of
running a ground wire to "get rid" of stray RF. Here's why:
1. You can't simply run a wire to "ground" RF in the first place.
That ground wire you are installing is a significant portion of a
wavelength at HF. On 10 meters, for example, an eight foot wire is
approximately 1/4 wavelength. If it is "grounded" at one end, the
other end is an open circuit. You have "grounded" nothing at all. At
lower frequencies, the effect is less pronounced because the portion
of a wavelength is less, but that ground wire never completely
"grounds" your equipment.
2. Even if you could "ground" your stray RF, why should you? RF
energy is expensive to generate. Do you really want to run that
expensive RF energy into dirt? Does dirt help your signal?
3. When you have RF in the shack, you do not have a grounding
problem, you have an antenna problem. Almost always, the source of
the RF in the shack is unbalance in the antenna system (including the
feedline), and that's what you should be fixing, not "grounding" the
RF to get rid of it.
4. For coax-fed antennas, the easiest cure in nearly all cases is to
install a 1:1 balun in the feedline, usually right at the point where
the coax connects to the antenna. It is also possible that the
physical layout of the coax is causing unbalance by picking up part
of the antenna's field on the coax shield. Relocate the coax so it is
physically balanced with respect to the antenna.
For those of you who'd prefer to go on "grounding" your RF, I hope
you have lots of patience in the pileups. You'll be needing it. :-)
73, Bill W6WRT
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