Spark gap switches for radar

An Essential feature of radar is the generation, by means of an oscillator, of high-energy pulses of short duration, repeated many times a second. The energy for these pulses is furnished to the oscillator from a power supply in a variety of ways. One of the most widely used of these is the “line type modulator” in which a pulse-forming network made up of a series of condensers and inductances is charged from the power supply through a choke and is then discharged by a switch so that a substantially constant current will flow for a predetermined short time through the primary of a pulse transformer coupled to the oscillator. This switch is, therefore, an essential component of this type of modulator.