Back in WW2 many communication lines were a single wire with an earth return ... years ago I was told a story (by people who were old enough to have been there) of doing that in the desert when they were facing Rommel .... guy picks up the phone, winds the generator to make it ring at the other end, someone picks up the phone answers "jawohl" .... sudden silence on the kiwi end, followed by scurrying around to find someone who spoke german so they could listen in.
Of course what had happened was that there were two parallel earth return phone lines on either side of the front, the lowest impedance path used both .....
Now this story was told to me by some old timers (people who could talk to you at the same time as they held a conversation in morse) - they told some great stories (all that I know of were true) - take it with the appropriate grain of salt
Of course what had happened was that there were two parallel earth return phone lines on either side of the front, the lowest impedance path used both .....
Now this story was told to me by some old timers (people who could talk to you at the same time as they held a conversation in morse) - they told some great stories (all that I know of were true) - take it with the appropriate grain of salt