HF receiver purpose?

• A. Convert signals from RF to AF
• B. Convert AF to RF
• C. Amplify audio
• D. Filter noise

Answer: (A)

The main idea is that a receiver’s job is to take the incoming high-frequency radio wave and convert it into a lower-frequency signal that can be heard or demodulated. In HF systems, the received RF signal is mixed with a local oscillator to produce an intermediate frequency, and then it’s processed down to audio frequency so you can listen to it or extract data. This RF-to-AF conversion is what makes the receiver functional for listening. Transforming AF back to RF would be a transmitter’s role, not the receiver’s. While amplification of the audio and filtering to reduce noise happen along the way, they support the process but do not define the receiver’s primary purpose.