This commercial transistor tester circuit (EICO 666) is from a Japanese publication from the 1960s. The switch selects the types of test with the switching of the terminals and the gain ranges.
This circuit generates 50, 100 and 200 Hz signals from a 2.2768 MHz TV crystal. The circuit can be...
This small power amplifier makes use of an output transformer given its design time. In fact, the...
This resistance meter with the CA3130 was found in an English publication from 1977. The circuit has...