> With a common buss bar you have ground loops between pieces of
> equipment. If a surge, lightning etc. should get through to one piece of
> equipment it will hopefully exit via the ground to the ground window.
> If there is a common buss bar the surge can enter another piece of
> equipment and go through it via the ground connection on it's way to
> ground. The ground lead from the buss bar will always have some
> impedance so it will be somewhat above ground with a surge.
> With individual ground leads to the ground window there is no loop
> through other equipment. Not always doable but it is the proper way.
> Gary K4FMX
That might be true if each piece of equipment in the shack
was totally isolated from every other piece of equipment. In
reality there are all kinds of incidental chassis connection
between gear. Gear that is on a common 12V supply, gear
that shares a coax shield connection, etc. There is also the
green third wire in the AC supply line from each piece of
gear to consider. If you run a wire from the chassis of each
piece of gear to your single point grounding window, you are
still going to have all those other connections woven between
gear. Some of those connections will be solid with large
conductors making the incidental connection and some will
be puny little RCA cables that incidental sneak path
connection. The buss bar concept gives you a hard low
impedance connection shorted across all those various
The real key to the single point ground concept is that your
trying to keep all the conductors entering the shack that
could be carrying a surge at the same potential. If that is
the case, the connection between the panel and the equipment
is not so critical. The main thing is that you don't want a
secondary path from the equipment to ground that doesn't
pass through the SPG window.
73 de Mike, W4EF.............................................
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
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