This analog frequency meter for low frequencies was found in Radio Electronics magazine from July 1958. The circuit has several scales with the frequencies indicated in the diagram.
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...