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Old July 10th 07, 10:14 PM posted to rec.radio.amateur.antenna
Nick Nick is offline
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First recorded activity by RadioBanter: Mar 2007
Posts: 25
Default Question on grounding rods


"Jim Lux" wrote in message
...
wrote:
John Doe wrote:


Isn't concrete an insulator??



"The preferred ground in most jurisdictions is a concrete encased
grounding electrode (aka a Ufer Ground, after the inventor's name Herb
Ufer).. "



What am I missing here?



That while dry concrete is a pretty good insulator it is hard to
find such just about anywhere other than Southern Arizona.

And even there, the concrete is probably damper and a better conductor
than the surrounding soil. Ufer's original work was developing grounding
techniques for ammo bunkers in desert areas, since the ground rods didn't
work.



I, too, am amazed - I though concrete, whilst it would be damp on the
outside underground bit, would be
substantially dry after setting, and a good insulator, being essentially
sand.. I guess its porous or microporous..

Nick