This variable oscillator was found in a Mullard transistors manual from 1960. The resistor R5 is 100k and the transistors are germanium of the time. Frequencies range from 15 Hz to 20 kHz.

This variable oscillator was found in a Mullard transistors manual from 1960. The resistor R5 is 100k and the transistors are germanium of the time. Frequencies range from 15 Hz to 20 kHz.