[TowerTalk] Station Ground
Ward Silver
hwardsil at centurytel.net
Fri Jan 14 23:19:09 EST 2005
One thing has been overlooked in the discussion of grounding with respect to
lightning and ac safety. I don't disagree with anything W3LPL had to say,
but I would like to point out that it is important to keep all of the
equipment close to the same RF potential as possible. This prevents RF
feedback and circulating current between pieces of equipment. Connecting
all of the equipment together with a low-impedance strap is a good way to
accomplish this.
Note that you probably can't make that RF potential equal to zero because of
the length of the connection between the strap and earth. That doesn't
matter, you just want the radio, the tuner, the audio mixer, whatever, to be
at the SAME potential to prevent current flow between their chassis. This
is a particular problem with "second story" shacks where a connection to
true ground may be meters long. At multi-position stations, it's also
impossible to keep all the equipment at the same potential and so you have
to settle for keeping the equipment at each position at the same potential,
even though that may be many volts different than one of the other
positions.
73, Ward N0AX
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