This transistorized circuit is powered by a voltage of 6 to 12 V providing high voltage for a neon lamp. The circuit is from a 90's publication. Modern equivalent transistors can be used.
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...