This circuit is from LinearTechnology Applications of 1997. The circuit uses components of the time used to raise the voltage of a battery from 3 to 6 V.
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...