Cable Locator (CB21303E)

This audio detector circuit can be used for cable identification. We found it in a Popular Electronics from the 90s.

Transistor Tester (CB18448E)
This simple transistor tester was found in a Japanese magazine in 1967. It tests general purpose...
Metronome (CB13033E)
Short duration pulses or "clicks" can be generated with the circuit seen in the figure. The...
High Gain Preamplfier (MSB023E)
A 25 mVpp applied to the input of this circuit produces in the output a 1 Vpp signal. The...