Hum problem solved

A. Joseph Ross
Sun Apr 13 16:27:32 EDT 2008

On 13 Apr 2008 at 7:47, Dan.Strassberg wrote:

> If there is a green pigtail ground wire on the outlet strip's power
> cord and the pigtail wire has a spade lug on the end that you are
> supposed to place under the head of the screw that secures the cover
> plate to the wall outlet, the spade lug might have been touching the
> head of the screw. To do an effective job of  reducing hum in audio
> equipment, the pigtail wire doesn't have to carry much current--maybe
> only microamperes. As a result, if the lug had merely been touching
> the screw head, it could have been sufficient for hum reduction--until
> something ever so slightly disturbed the ground wire's position.
> That's all it would take.
Good point.  But (1) the head of the screw is fairly well covered 
with paint to match the color of the cover plate; and (2) the wire 
lug was nowhere near the screw.  So there must be some other reason 
why the system worked previously.  But since it's working now, that's 
only a matter of idle curiosity, not a problem I need to solve.

A. Joseph Ross, J.D.                           617.367.0468
 92 State Street, Suite 700                   Fax 617.507.7856
Boston, MA 02109-2004           

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