This circuit was found in the July 1978 issue of Radio Electronics magazine. The circuit uses a common digital voltmeter as the indicator. The sensors are integrated circuits of 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...