If you have the skills and can get your hands on SMD components, you can assemble this small amplifier. We found it in the Radio Electronics Experimenter special edition from 1990.
This circuit is intended to trigger a TTL door or flip-flip from a signal coming from an SCR....
This circuit found in a 1988 documentation, uses a piezoelectric or crystal capsule as a...
This circuit, which can be used as a shield, was found in Radio Electronics from the 90s. The...