We found this circuit in the November 1984 Radio Electronics magazine. The base frequency is given by C1. The power supply can be between 3 and 12 V.
This circuit was found in a documentation of the year 1958. The transistors are germanium types...
Found in a 90’s 303 Circuits, this circuit uses components that are still common and has a common...
We found this circuit in a 1990 documentation. It is totally up to date by the components it uses...