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.
The transistors of this circuit may be general purpose and the power supply comes from the TTL...
We found this circuit with the CMOS4046 in the August 1994 Electronics Now magazine. The circuit is...
This setting appears with variations at various points on this site. This is from a Motorola...