Philip Pemberton wrote:

> I wouldn't have thought you'd get a ground loop if they were all running
> off the same mains cable though?

Always when you have two separate ground connections between two devices,
you have a ground loop. Of course, the bigger the loop, the bigger the
chance of it creating problems, so having a big ground loop that goes all
the way to your central mains connection box is worse than having a loop of
a few meters around your bench. But a loop is a loop... if the current can
go in circles, it has a tendency to do that :)

That's probably a case where a certain ground connection resistance is
helpful. Not advisable, nonetheless.

Gerhard

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