Quenched-spark transmitter G 1400 for submarines

The G 1400 was used in the German Navy. The transmitter's compact design was designed for the conditions found in a submarine (humidity, high temperatures, and confined space). The middle part comprises the spark gap, an ammeter, and a current regulator. On the left is the surge circuit and on the right is the antenna variometer. Alcohol vapor accelerates the quenching of sparks, even in high humidity.