Negative ion detector (CB21001E)

This tube circuit was found in the magazine 73 for radio amateurs in an issue from the 1980s. Note the transformer used to power the circuit.

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Operational RIAA Preamplifier (CB14846E)
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76 dB Gain Preamplifier (CB25695E)
This high-gain amplifier was found in the March 1994 issue of Electronics Now magazine. The...
Process timer (CB21865E)
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