Melody circuit (CB8007E)

Found in a 90’s Radio Electronics magazine, this circuit uses a component from the time, difficult to obtain today.

Speed Alarm (CB4956E)
This circuit was obtained from an old documentation, but as it uses still current components it can be...
LM390 gain 20 amplifier (CB25307E)
This audio circuit has an output power of 1 W. We found it in the Radio Electronics magazine of...
American Siren (CB4468E)
This circuit that uses only discrete components (transistors) mimics the sound of an American...