Found in a Popular Electronics from the 90s, this circuit is intended to measure the harmonic distortion of an audio signal. The circuit can be tuned between 970 and 1030 Hz.
This circuit was found in an American publication called Ham Radio. The circuit uses still current...
From an audio signal, this circuit gets two signals of the same amplitude and opposite phases....
Found in an Electronic Design from 1968 this circuit generates a linear sawtooth signal modulated...