Found in an old American publication, this circuit generates signals of various waveforms. The frequency depends on the components. Operational amplifiers are from the period.
An interesting timer is shown in the figure, using one of the 4 NAND gates of the integrated 4001....
General Electric suggests this circuit in a 1980s documentation. The operational of the time is...
This simple adjustable source uses a PNP transistor that can be the BD136 for even slightly higher...