This circuit with the NE602 was found in the February 1997 Electronics Now magazine. The NE602 integrated circuit is not very common these days.
This type of circuit appears in several versions and approaches on this website. This was found in a...
The integrated circuit used is no longer common today. The circuit is from Motorola's 1990 Linear...
This circuit is from an old manual, but can be easily assembled as the integrated one is still...