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Old September 28th 07, 04:46 PM posted to rec.radio.shortwave
Roadie Roadie is offline
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First recorded activity by RadioBanter: Jan 2007
Posts: 290
Default Interesting article on "typical" 3 wire power distribution.

On Sep 28, 9:00 am, wrote:
While intended for audio and video production houses, it is a very
good over view of the "whys" of
NEC grounding.

http://www.campuspa.com/downloads/grounding_tutorial.pdf

The graph on page 28 is very interesting as it shows the noise on a
"typical" ground conductor.
And the graph on page 31 shows the impedance of a 10' section of wire.

Please not the comments Mr. Whitlock makes are directed at the audio
video world.
But his explanations are helpful in gaining understanding that the
house mains, and the
house NEC ground are NOT designed with RF in mind!

Mr. Whitlock is one of the true wizards in the high end audio world.
His Jensen transformer company markets the best audio isolation
transformers available.

Will Sent me this link. A report on real world noise radiation from
"balanced" power distribution
systems.http://fjallfoss.fcc.gov/prod/ecfs/r...or_pdf=pdf&id_...

Terry


Excellent information that is written in an understandable form. He
busts several myths.


MYTH: Exotic Cables Stop Noise
Expensive cables, even if double or triple
shielded, made of 100% unobtainium,
and hand woven by virgins will have no
significant effect on hum or buzz ......
Only the resistance of the grounded
conductor can make a difference!

MYTH: Poor Shielding Causes Noise
Common-impedance coupling causes 99% of
noise problems in unbalanced interfaces
Trivial noise contributor in modern systems
Audiophile cables from famous maker, costing
$80 to $500 per 1-meter pair, have no shield
at all - wires are simply woven together!
Shielding can be issue with old vacuum-tube
equipment because of high Zo in drivers