This circuit appears in several versions in publications of the time and can be modified by changing the capacitors. This one is from Radio Electonics magazine from October 1992.
This circuit found on a William Sheets can be used with a headphone or external amplifier. The...
In the figure we have the circuit of a complete audio generator using the 741. The circuit was found...
This monostable multivibrator with signals in phase opposition was found in October 1986 Radio...