This circuit with output powers of 2 to 3 W depending on the power supply was found in the magazine Radio Electronics of April 1990. The speakers are 8-ohm.
This FM advertising suppressor (SCA) decoder circuit was suggested by Signetics in a 1980s...
We found this circuit in an old General Electric documentation. In fact, PUTs are not common...
We find this simple musical instrument in a 1977 Radio Shack documentation. The key resistors must be...