Found in an 1989 R-E Experimenters Handbook, this circuit produces several sound effects that can be modified. The signal must be applied to an external amplifier.
This circuit is from 1968 General Electric documentation. It can certainly be adapted for any...
This tester from a 1960 magazine is only for capacitors with insulation voltages above 200 V (110...
Found in a 1991 publication this circuit can be assembled with more modern components. We can use...