This 1967 commercial radio covers 6 wave bands selected by appropriate coils. The circuit currently uses critical components, such as coils and transformers.
The circuit shown in the figure is a simple test of NPN and PNP transistors. The circuit detects the...
This circuit is from an old American documentation, from 1977, but it can be implemented with more...
Found in a manufacturer documentation from the 90s, this circuit makes use of period components. The...