This circuit, for frequencies up to 100 kHz, was found in American documentation from 1970. The circuit can serve as a reference for projects with modern equivalent components.
This oscillator with few components for frequencies that can reach 1 MHz was found in Radio...
This transistor tester was found in a 1980 publication. The transistor can be the BC548 and the...
This proximity sensor was found in a 90s Popular Electronics. The base is a PLL567 that operates...