This circuit is from the 1992 Radio Electronics Handbook. The components used are from the period, with emphasis on the 2-digit display driver.
This narrowband data receiver is from the Philips Databook of 1990. The circuit is powered by 5 V...
This circuit was proposed by an old American documentation for listening to SSB stations. The...
This voltmeter for continuous voltages has several scales and is totally passive. The diodes are...