This circuit is for analog TV video signals and was found in the March 1988 issue of Radio Electronics magazine. The circuit uses a Maxim integrated circuit that can still be found.
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....