Two circuits sharing a common ground path causes electronic noobs no end of confusing grief. Because the two circuits are coupled via the ground inductance and resistance.
And a circuit that forms with it's ground a large loop is another source of confusing grief. A big loop is an inductor. And will pickup magnetic energy passing through it.
Two circuits sharing a common ground path causes electronic noobs no end of confusing grief. Because the two circuits are coupled via the ground inductance and resistance.
And a circuit that forms with it's ground a large loop is another source of confusing grief. A big loop is an inductor. And will pickup magnetic energy passing through it.