🔍 Key Concepts

• Automatic Frequency Control (AFC) function in marine radar receivers • Difference between magnetron (transmitter) and klystron/local oscillator (receiver) in a radar set • What part of the radar chain can you actually adjust versus what simply arrives from outside

💭 Think About

• In a radar, which component produces the transmitted pulse, and which produces the local reference frequency for the receiver to stay tuned? • Can the radar set actively change the frequency of echoes returning from a target, or only adjust its own internal oscillators? • Which choice refers to gain (amplification) rather than frequency, and how does that relate to the name Automatic Frequency Control?

✅ Before You Answer

• Make sure the function you pick actually involves frequency, not gain or amplification. • Ask: does this system act on the transmitter or on the receiver’s local oscillator to keep them matched? • Eliminate any option that suggests controlling the incoming echoes themselves, since the radar cannot change what has already left the antenna and bounced back.