This circuit is from an American 1967 documentation and can be implemented with modern equivalent transistors. The circuit serves as a Q multiplier.
This didactic circuit was found in an English publication of 1965. The sensor is an LDR and...
This micro FM transmitter uses a tunnel diode as an oscillator. I found it in an English...
This bistable control uses a 4069 as bistable. The circuit can drive relays up to 100 mA with the...