Station ground bus bars are an obsolete grounding practice,
modern design practices provide far superior AC power
safety and lightning protection.
Grounding serves several purposes, including:
- electrical safety
- lightning protection
- antenna RF return path
- signal reference
Amateur radio installations are primarily concerned with
electrical safety and lightning protection. Antenna RF
return paths should be provided as an integral part
of properly designed antenna systems, station grounding
is a poor alternative. Signal reference grounds are often
used in large computer, communications and industrial
facilities and do not apply to amateur radio stations.
Electrical safety grounding is provided by the green wire in
AC power wiring in the United States and other North
American countries. Every piece of equipment in your station
should use a green wire ground, and the integrity of the green
wire ground should be preserved from each equipment
to the main circuit breaker panel in your home. Never
tamper with green wire grounding in any equipment or with
the green wires in the electrical wiring in your home. Your
safety, your family's safety and fire protection of your
home depend on it.
Station ground bus bars were intended to provide lightning
protection through a very short heavy ground wire from the
station equipment to a well designed ground system in very
close proximity to the station. In some cases, this approach
could also compensate for poorly designed antenna RF
return paths.
The modern design practice is to bond all RF cables, rotator cables
and control cables to a common grounding "window" at the entry
point into the home. All other cables (AC power, telephone,
cable TV, satellite, etc) penetrating the wall of the building
should be bonded to the grounding window. While a wide
ground strap could be run from the grounding window to a
station equipment bus bar and then to each station equipment,
it is likely to have such high impedance that it is highly unlikely to
perform any useful function.
73!
Frank
W3LPL
donovanf@erols.com
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See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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