We found this circuit in a French documentation from the 80's. The components used are still common and the circuit can generate signals from 10 Hz to 100 kHz.
This circuit was found in an English magazine from 1973. The magazine no longer exists, but the...
This radio version of 1 transistor, extensively explored on this site and in this section, is from...
This dual control was based on Texas Instruments documentation for the CD4050. The circuit has two...