HIGH SPEED PULSER

A hybrid combination of transistors and vacuum tubes for controlling the conduction of high frequency tubes such as klystrons and the like in respone to the resonant charging and discharging of the klystron's grid capacitance. A pair of mutually opposite conductive vacuum tube switches alternately operate to resonantly charge and discharge the tube capacitance through an inductance in response to a first trigger signal applied to turn the tube "on" and to a second trigger to turn the tube "off" in a bistable mode. In the event that the second trigger signal is not applied within a predetermined time period, or is missing, a transistor switch circuit causes the vacuum tube switches to operate in a monostable mode to automatically turn the klystron "off.