Found in a Popular Electronics from the 90's, this circuit makes use of an integrated from the uncommon era today. The circuit serves as a reference.
This circuit was found in old documentation. It can be made based on modern components. The time...
This small two-transistor AM radio was sold in the 1960s in Japan. The circuit was powered by two...
I found this circuit in an old English magazine from 1979, but it can be easily assembled with...