This circuit is from Mullard 1969 documentation. The circuit operates at a relatively high supply voltage and has a 10 Vpp output. The transistors are of the time, but admit equivalents.
This circuit was obtained in a 1977 Radio Handbook. The transistor is from the era and the coils...
We find this circuit in the 80's own component manual. The power supply should be from 4 to 30 V...
Obtained from a 1969 documentation, this circuit can operate at frequencies up to 500 Hz, counting up...