This circuit generates sinusoidal signals between 300 and 3000 Hz. We find a 303 Circuits from the 90's. The operational ones are types with FET. The power supply must be symmetrical.
This circuit is from a 1982 documentation. It can be modernized using LEDs in series with 470 ohms...
We found this circuit in a 1985 technical publication. The circuit uses PUTs to drive lamps....
This circuit appears with variations in other points of this section. This version is from...