This circuit was found in a 1964 Electronic Design. The circuit can be implemented with equivalent modern transistors. Note the high supply voltage.
This ultra-simple meter uses an output transformer and a small speaker as a microphone. The...
This circuit generates noise pulses for audio equipment probes. The circuit is from a 90’s 303...
This 5-band function generator circuit was found in the April 1994 Electronics Now magazine. The...