In message , Clive Mitchell
writes
In message , raden
writes
You NEVER disconnect the mains earth from equipment.

Well, actually ....

sometimes you do

on a scope - might be naughty, but sometimes necessary

That's an electrical workshop environment. Besides the correct
procedure is to use a mains isolation transformer where possible. These
days I use a battery powered scope.

Which were how common exactly, 20 years ago ?

--
geoff