This circuit, which uses a quadruple comparator, was found in old American documentation. The response curve is shown next to the diagram and can be adjusted in the trimpots.
We have in the figure a traditional amplifier configuration with operational amplifier. The source...
This circuit was found in a 1977 Radio Shack documentation. The circuit is TTL, which must be...
This circuit is suitable for modulating small FM transmitters for eavesdropping or espionage. The...