This simple rain, leak or moisture detector circuit appears in other places on this site with slight variations. This was obtained in an English documentation from the 70s.
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...