On Fri, 18 Jun 2010 08:28:29 -0700, jimlux wrote:
>Hams get all hung up on the "ground" word and that leads to a lot of
>confusion, for instance, if your shack is on the second (or tenth)
>floor. You still need a common point to tie/reference things to, even
>if you're somewhere a long ways from the dirt.
YES! The word GROUND is badly mis-used here, and leads to a LOT of
confusion.
>A fascinating paragraph comes up much later in the emerald book (since I
>have it open..)
>Importantly, and because of the high-frequency components in the
>lightning strike?s current path, special wiring and grounding techniques
>must be used to properly conduct lightning currents on sites where
>electronic equipment is installed. The use of appropriate low-inductance
>wiring means with appropriate I2t rating for the conductor(s) and
>multipoint grounding (MPG) *as opposed to* high rms current-carrying
>capability techniques and single-point ground (SPG) arrangements are the
>core of this special design requirement.
>Note what that says... SPG may be the *wrong* way to deal with lightning.
You're right on target, Jim. This simple-minded SPG concept has some
serious shortcomings, is built on some fuzzy thinking and false
assumptions, and leads to a lot more fuzzy thinking.
73, Jim K9YC
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