This circuit was presented in a January 1990 Radio Electronics magazine article as part of a home theater sound effects system. It consists of a 3 kHz high-pass filter.
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....