Suggested by Philips in 1966 documentation, this limiter can be found elsewhere on this website. The circuit is for 7 V, but can be changed to other voltages, depending on the zener diodes.
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...