This 1967 commercial radio covers 6 wave bands selected by appropriate coils. The circuit currently uses critical components, such as coils and transformers.
Found in a documentation from the 90s, this circuit has a typical accuracy of 2% with 20 V signals at...
This circuit was obtained from an English publication from 1977. The integrated circuit is a...
The configuration shown was found in an old American manual. The circuit can be made with modern...