This flip-flop circuit with general purpose transistors was found in American documentation from the 1980s. The maximum operating speed depends on the transistors. Diodes are commonly used.
This circuit was found in an Electronic Design from 1967. The circuit uses two triacs being T2...
Found in old American documentation, this circuit can use crystals between 27.5 and 33 MHz...
This shield from the 60's uses a germanium transistor of the time and a common type of relay of...