In telecommunication, a neutral direct-current telegraph system is a telegraph system in which (a) current flows during marking intervals and no current flows during spacing intervals for the transmission of signals over a line, and (b) the direction of current flow is immaterial. Synonymssingle-current system, single-current transmission system, single-Morse system.
... 1942 Jean Moulin parachuted to Arles with two other men and radio equipment and continued to Marseilles. De Gaulle had sent him coordinate activities of diff ...