What does the audio amplifier do in a radio receiver?

What does the audio amplifier do in a radio receiver?

• A. Amplifies the weak audio signal from the detector so it can be heard
• B. Converts radio waves to electrical signals
• C. Tunes to a frequency
• D. Filters noise

Answer: (A)

The main idea is that after the detector demodulates the signal, the result is a very small audio waveform. The audio amplifier's job is to boost that weak audio signal so you can hear it clearly through a speaker or headphones. In a radio receiver, the signal path goes from the antenna through the RF front end to tune and filter, then through the detector to recover the audio, and finally through the audio amplifier to provide enough power and proper drive to the speaker. The amplifier increases the signal’s amplitude (and can help with impedance matching to the speaker), making quiet broadcasts audible. It isn’t responsible for turning radio waves into electrical signals—that’s done by the detector—or for tuning to a frequency—that’s the job of the tuning network. Nor is its primary role to filter noise, though filtering may occur elsewhere in the chain.

The main idea is that after the detector demodulates the signal, the result is a very small audio waveform. The audio amplifier's job is to boost that weak audio signal so you can hear it clearly through a speaker or headphones. In a radio receiver, the signal path goes from the antenna through the RF front end to tune and filter, then through the detector to recover the audio, and finally through the audio amplifier to provide enough power and proper drive to the speaker. The amplifier increases the signal’s amplitude (and can help with impedance matching to the speaker), making quiet broadcasts audible. It isn’t responsible for turning radio waves into electrical signals—that’s done by the detector—or for tuning to a frequency—that’s the job of the tuning network. Nor is its primary role to filter noise, though filtering may occur elsewhere in the chain.