This circuit was found in old documentation, but the setting applies to any operational. Resistors and capacitors determine the frequency. For the indicated values the frequency is 10 kHz.
This is an old test circuit for integrated TTL counters, feeding a Nixie tube, common at the time....
This old oscillator using germanium transistors has a high impedance headphone as inductor to...
This preamp with several inputs using germanium transistors from the time was found in Japanese...