This circuit is from an American 80's documentation. The integrated circuit is from the time and the sensor consists of a smoke chamber measuring its transparency change.
The purpose of this simple stabilized source, obtained in a documentation from the 70s, is to...
This simple receiver for listening on a crystal phone tunes the range of medium waves. The circuit...
This medium- or short-wave receiver circuit was found in documentation from the 1980s. The circuit...