This crystal or galena radio is one of the many versions available on this website. This is from a documentation from the 70s. The coil is formed by 50 + 50 turns of wire 28 in a ferrite rod.
This circuit was found in an Electronic World of 1968. The circuit uses power transistors of the...
This circuit is from a Linear Technology integrated circuit manual from the 1990s. The circuit...
This simple super-regenerative receiver was found in American documentation from the 1980s. The...