Cable Locator (CB21303E)

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

4040 Oscillator (CB14984E)
This traditional rectangular oscillator configuration generates signals up to a few megahertz...
Music Generator (CB9882E)
This circuit is just a curiosity found in a 1990 documentation, since the integrated circuit used...
Voltage Drop Alarm (CB1530E)
This circuit goes into operation producing a sound on a small speaker when the supply voltage...