This ultra-low noise amplifier and simple power supply was found in Analog Devices documentation from the 90's. The circuit can be implemented with modern equivalent components.
This drain dip oscillator was found in an old English documentation. The JFET can be of any type...
This SCS counter circuit was found in a 1964 General Electric documentation. The circuit has a...
This is the circuit of a commercial radio from the 60s, sold in Japan. The circuit shows the...