This receiver circuit was found in a Hands On Electronics from the 90s. The circuit uses a PLL 561B that is not a common component today.
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...