A proper "ground" or earth connection is *not *necessary for proper and
clean operation of an amateur radio station on HF ! ! In the past ARRL
has spread this rumor so much that it's become conventional knowledge and
lore of a good station installation. ARRL has finally come to terms with
that bit of miss-information in their publication of the "Grounding and
Bonding" book. Order one and have a good enlightening read!!! Whenever
there is a problem, the usual and stock comment is "ground it". This is
baseless in most cases when it comes to RF fields. There are three types
of "ground":
1) The safety ground required by building code. This is the green wire
that should connect to any exposed conducting portion of equipment that
plugs into standard 120 VAC sockets in our homes.
2) ESD, static, bleed "ground". This may not actually be a ground or
earth connection, but just something to dissipate static discharges.
3) Lightning protection "ground" or return. This can get mighty expensive
and the cost of a professional (Uncle - been there, done that) is well
beyond the financial means of the typical amateur.
There ain't no such thing as "RF ground", only an RF *return*. The ISS
doesn't require a long wire connecting to earth to bidirectionally
communicate to earth via RF. The Crab Nebula doesn't require a ground to
fill deep space with copious amounts of broadband RF energy (and visible
and IR and X-rays and gamma rays and gravitational waves). When the Sun
develops a major solar flare, it doesn't require a "ground" to fill our
local space (and kill the ionosphere) with copious amounts of
electromagnetic energy. What RF fields *do* require is a return. In the
case of a vertical monopole over a good radial system, the radial system
becomes the return (in a non-radiative manner). With the center fed
1/2-wavelength dipole each half of the dipole serves as the return of the
"other" half of the dipole. The dipole and other similar radiating
configurations do not require a "ground" to function properly.
Here in N. Colorado about a decade ago, we had a serious RFI problem with a
large active matrix LED sign in Fort Collins. On contacting the owner of
the store, the first thing they commented was, "Oh, that sign is not
grounded....we'll fix that". A week later they called us back to test the
effectiveness of their grounding exercise of the metallic structure of the
sign. *Of course, grounding the sign made absolutely no difference at all.*
This was one of the few cases where the FCC had to get involved to cure the
problem. It took a threat from FCC of major fines to motivate the owners
to get off their hind quarters. Ultimately the supplier of the sign was
held responsible for eliminating the RFI. And........once again, it
turned out to be a problem with outsourcing certain aspects of the design
to China.
"Grounding" is most times ineffective in practice AND in theory of RF
fields.
Dave - WØLEV
On Tue, Oct 26, 2021 at 9:32 PM Gary Smith <wa6fgi@steeltrails.net> wrote:
> Hi Joe and the list
>
> To your friends who are taking a whipping via harmonics, ask them if
> their station is properly grounded.
>
> The very few who have asked me about unwanted signals, when I ask if
> their station is grounded, I get some strange looks and mumbles and
> usually "I gotta go home and check".
>
> Gary...wa6fgi, located in what's generally known as"Baja North
> Highlands", 95842 country.
>
> On 10/26/2021 10:54 AM, Joe wrote:
> > Have good radio friends in North Highlands, California, that get blasted
> by harmonics (While on 75 meters) from a clear channel AM station, KFBK.
> The station has been notified, multiple times, but they just shine the
> complaints on. They could care less about the interference to
> communications they are creating. The FCC is not concerned either, they
> are too busy trying to control the internet than address real FCC issues. L
> >
> >
> >
> > Joe W7RKN
> >
> >
> >
> > -----Original Message-----
> > From: RFI [mailto:rfi-bounces+w7rkn.7=gmail.com@contesting.com] On
> Behalf Of Cortland Richmond
> > Subject: Re: [RFI] Splatter from AM Radio Station WNTS Indianapolis and
> Resolution
> >
> >
> >
> > _______________________________________________
> > RFI mailing list
> > RFI@contesting.com
> > http://lists.contesting.com/mailman/listinfo/rfi
> _______________________________________________
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> RFI@contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi
>
--
*Dave - WØLEV*
*Just Let Darwin Work*
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