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We found this circuit in the November 1992 issue of Radio Electronics magazine. The 30V power supply must be symmetrical and preamplification stages are included.
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...