Found in a 1980s American documentation, this crystal-controlled oscillator generates 100 MHz signals. The crystal used is 20 MHz. Modern equivalent transistors can be used.
Found in a 1968 GE documentation, this circuit is intended to drive an SCR from a control signal....
Found in an English Maplin documentation from 1983, this circuit generates separate frequency...
This TTL siren is formed by two oscillators using each two Gates of a 7400. Frequency or the...