It consists of an induction coil (box in back), powered by a battery (not shown), which generates pulses of high voltage electricity which are applied to a spark gap between the two brass balls on the brass arms (top). One side of the spark gap is attached to a wire antenna suspended from the ship's mast. The other is attached to a ground connection, which in a ship was usually a wire or plate dipping in the water. Each spark between the balls excited a brief radio frequency sinusoidal oscillating current in the antenna, which declined rapidly to zero, called a damped wave The energy in the oscillating current was radiated from the antenna into space as radio waves.

The antenna acted as a resonator, so the wavelength and therefore frequency of the radio waves produced was determined by the length of the antenna. The antenna functioned as a quarter wavelength monopole, so the wavelength of the radio waves was 4 times the length of the antenna. The vibrating interrupter contact on the induction coil generated about 20 to 50 high voltage pulses per second, so the output of the transmitter was a repetitive string of damped waves, repeating at an audio rate, so the signal sounded like a buzz or whine in the receiver earphones.