This small commercial radio for the MW band with germanium transistors was found in Japanese documentation from the 1960s. The circuit is powered by a 9 V battery and has a 455 kHz IF.
Originally this circuit is from an English magazine, but I found it in Argentina's Radio Chassis...
This circuit was found in a Popular Electronics from the 80's. The circuit can be powered with...
This circuit was found in an American 1980s documentation. It analyzes the exhaust gas of a...