This circuit was found in ancient American documentation. It provides a 70 Vpp signal at frequencies up to 100 kHz. Observe the high supply voltage.
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...