This circuit is designed to analyze the distortion of an audio signal. We found it in an article in the October 1988 Radio Electronics magazine that teaches how to use it.
This circuit for cars with mechanical ignition systems was found in the Electronics Experimenter handbook...
This code practice circuit was found in a 1990s issue of Radio Amaterur Today magazine. It...
The circuit presented was found in the Linear Applications Handbook of the National Semiconductoir of 1994....