This commercial receiver from the year 1958 uses two AA cells as Power supply. The circuit is intend to receive MW station and the transistors are germanium types not easy to find today.
Found on Popular Electronics from 1970, this circuit fires a xenon lamp producing a C1-dependent...
Found in documentation from the 1980s, this highly sensitive circuit is based on the conduction by the...
This simple circuit helps to save incandescent lamps by leaving their filament slightly heated and thus...