Which of the following best describes the purpose of a transmitter in a radio system?

The purpose of a transmitter in a radio system is primarily to convert audio signals into RF (radio frequency) signals. This conversion process is essential because the audio signals, which are typically in a low-frequency range and meant for human hearing, must be transformed into higher frequency RF signals for them to be transmitted effectively through the air over long distances. The transmitter takes the audio waveform, modulates it onto an RF carrier frequency, and outputs this modulated RF signal through the antenna for reception by radio receivers.

Transmitter functions include amplification of the modulated RF signal to ensure it can cover the desired transmission range and maintaining the necessary fidelity of the original audio signal. The importance of this role cannot be overstated, as it forms the foundation of all radio communication by facilitating the transmission of information over the airwaves.

Other options do not accurately capture the primary purpose of a transmitter. While enhancing sound quality could be a secondary benefit of signal processing before transmission, it is not the main function of the transmitter. Similarly, while a transmitter does provide the signal that is sent to the antenna, it is not solely responsible for powering the antenna itself. Additionally, the task of receiving and decoding signals is characteristic of a receiver, not a transmitter.