This traditional circuit generates a 200 Hz sinusoidal signal. The frequency depends on the capacitors and the transistor can be a BC548. We found this circuit in a 1979 documentation.
EZP-Q metallized polypropylene capacitors from Panasonic's can be purchased from Mouser...
We found this circuit in Radio Electronics magazine from January 1962. The circuit requires a good...
This circuit from a 1979 publication uses FETs which can be BF245 and integrated circuits, unlike...