Design of a Loran transmitter

For commercial use the war-time Loran transmitter produced too much interference owing to the wide pulse. A new transmitter is described in which the pulse width is 40 musec at half amplitude and the rise time is 25 musec. The desired output pulse is obtained by amplitude modulation of a linear stage and raising this to the desired power of 1 MW in a final amplifier stage of 12 type-5 680 tubes in push-pull parallel connection. Block diagrams and circuit diagrams with pulse shapes at each stage are shown together with photos of the transmitter and amplifier cubicles.