We found this time base of 0.1 to 90 seconds in a circuit manual from the 90s. The single-use transistors used are common and the frequencies given by the adjustment by the potentiometer.
This circuit was found in ancient American documentation. It provides a 70 Vpp signal at...
The figure shows a Wien Bridge circuit with non-linear feedback. The resistance of the RL lamp is...
Found in documentation for radio amateurs of the 70's, this circuit generates signals from 18 to 24...