This low frequency sinusoidal oscillator was obtained in documentation from the 1970s. Operational equivalents can be used. The FET is a general-purpose type.
This circuit was found in the Linear Applications Handbook of the National Semiconductor of 1994....
This oscillator with the 4049 can generate signals up to about 14 MHz according to the article in the...
This circuit of a voice-controlled switch, Vox or sonic switch was obtained in a Popular...