The circuit shown in the figure can be used on a data transfer bus using an appropriate family integrated. The circuit is TTL technology and must be powered from a 5 V supply.
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...