What component provides operating voltage to a radio set?

The power supply is the component responsible for providing the operating voltage necessary for a radio set to function. It converts electrical energy from a source, such as AC mains or batteries, into a suitable voltage level that can be utilized by the radio's internal components, including the transmitter and receiver. This ensures that all parts of the radio can operate effectively to process signals, transmit and receive information, and power any display or control elements.

In the context of the other options, the transmitter is involved in sending out radio signals but does not provide the voltage itself; it relies on the power supply. The antenna serves as a medium for transmitting and receiving radio waves but does not supply power. The receiver processes incoming signals and converts them into audio or data, but it also depends on the power supply to operate. Thus, the power supply is essential for powering the radio system as a whole.