This small 1W turntable amplifier was found in the 1975 RCA tube manual. It is a commercial circuit at the time.
This circuit with 10 MHz and 1.25 MHz TTL outputs was found in an American documentation from the...
We found this circuit for vocal effects in the September 1990 issue of Radio Electronics magazine. The...
This is a voltmeter with high input resistance. The transistor is germanium. We found it in an...