Power line carrier system is common in home appliances networking. One benefit of using this kind of transmission line is that we don’t have to deal with additional wiring for data or signal communication, since all we need is already provided when we plug the power jack into the power outlet/stop contact. The circuit depicted in the schematic diagram below is suitable for high-quality transmission of music or speech. This circuit has some advantages like wireless FM transmitter/receiver operates over standard power lines, noise free and high quality. The THD of this circuit is under 1/2% with frequency response of 20-20, 000 Hz. This circuit also used for mono transmission to single remote speaker, so two input terminals are provided. This circuit can transmit the carrier with distance that include all outlets in and around a suburban home and yard.  Here is the schematic diagram of the  circuit:

Carrier System Transmitter circuit schematic