This filter was found in an 80's English publication. However, it can be implemented with modern operating systems. The circuit can tune frequencies in a range from 10,000 to 1.
Found in a 1980 documentation, this circuit drives a transducer (X1) when the car battery has its...
The integrated circuit used in this circuit from a 1987 documentation is no longer common today....
This 1967 commercial radio covers 6 wave bands selected by appropriate coils. The circuit...