We found this circuit in the September 1971 Radio Electronics magazine. The SCR can be any of the 106 series and the buzzer can be replaced by a relay according to the 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...