Radio Transmitter Power Cables
These power cables came in different lengths. Radio transmitter cables had a standard configuration with 6 connecting pins. Both the male and female plugs had special grooves on them to prevent plugging into a device which used a different voltage, thereby damaging the device. The female plug was attached to the transmitter, while the male plug was attached to the power supply. Two of the six pins supplied the filament (heater) voltage (+,-), Anode (grid) voltage (+,-), one pin for the +Umf and one pin for Ground.
Here is a 1 meter radio transmitter power cable. It came attached to a 10W.S.c (1945). At the other end of this cable are five separate insertion pins that connect the H+, H-, A+, A- and Ground to the power source
This is the radio receiver plug. Note the grooves on the side of the plug. Military radio transmitters had corresponding grooves on their power receptacles to prevent a receiver power cable to be accidentally inserted.