When locating wire and valves why does the strength of signal and what you’re reading change when you change from a ground to using the common, for instance? Say I hook up to the blue wire in a multistrand and ground my other connection off of my locator base. I’ll be able to trace my wire until it terminates at the valve. I’ll be able to hear the wire the whole time and when I get to the valve it’ll scream at me. If I hook up to the same blue wire but put my other connecting from my locator base onto the common, then the signal for the wire diminishes significantly until I get on top of any valves at which time the locator will scream. I noticed today that a splice in a valvebox gets the same screaming ping as a valve. What makes the difference in these? Seems like any signal running through the wires would produce the same ping on the locator regardless of if it has a ground or is using the common. School me.