Mini Organ (CB21653E)

This toy organ was found in Popular Electronics from January 1967. It can be constructed from modern equivalent transistors.

CMOS Time Base (CB17502E)
This circuit generates 50, 100 and 200 Hz signals from a 2.2768 MHz TV crystal. The circuit can be...
Small Transistor Amplifier (CB1370E)
This small power amplifier makes use of an output transformer given its design time. In fact, the...
Ohmmeter (CB21986E)
This resistance meter with the CA3130 was found in an English publication from 1977. The circuit has...