Found in the 1990 special issue of Radio Electronics Experimenter magazine, this circuit uses an automobile ignition coil. Adjustments can be made to suit the coil.
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...