This circuit was found in the March 1984 issue of Radio Electronics magazine. The sensor is a transistor. The module is a common type at the time.
This circuit is from a documentation from the 70s. The circuit uses logic gates of the time, which...
Found in the July 1968 Supertena Bulletin of a Popular Electronics, this receiver makes use of the...
The circuit shown was found in the February 1994 issue of Electronics Now magazine. The circuit...