This circuit was found in documentation from the 1970s. However, it can be implemented with modern transistors such as 2N2222 for Q1 and BF494 for Q2. The crystal depends on the desired frequency.
Found in the 1974 Ferranti transistor manual, this Schmitt trigger circuit uses general-purpose transistors...
This circuit was developed to test suspect 4001 and 4011 integrated circuits. The circuit is from...
This power source with silicon diodes at a time when valves were still used was found in Radio...