This simple transistor tester was found in a Japanese magazine in 1967. It tests general purpose transistors of both the NPN and PNP type and is powered by 4 batteries (6 V).
This simple oscillator is yet another of the many versions of sonic insect repellent that we find...
The circuit in the figure operates at frequencies from 4 to 20 MHz and also uses a common junction FET...
This TTL counter was found in the April 1979 issue of Radio Electronics magazine. The circuit is...