This circuit was found in a 1965 Electronic Design. What it does is respond only to positive pulses (above zero volts) and can be used in automation systems.
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...