This is the application note circuit of the integrated circuit used with the LASER diode. The circuit was obtained from the Electronics Experimenter's Handbook of 1992.
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...