This circuit for low frequency data transmission was found in the May 1977 issue of Radio Electronics magazine. The circuit modulates the signal at two frequencies for bits 0 and 1.
This 1960s Japanese commercial AM radio uses 6 germanium transistors and is powered by 4...
This well-designed bistable circuit was found in a 1970s documentation. Transistors can be current...
This microamplifier was found in a Popular Electronics from June 1968. It is an experimental...