🔍 Key Concepts

• FM (frequency modulation) vs AM (amplitude modulation) in radar signals • Function of a local oscillator and automatic frequency control in radar receivers • What a discriminator circuit does in general electronics (how it treats frequency changes)

💭 Think About

• Which answer choices talk about bearings or range processing, and which talk about signal processing inside the receiver? • In basic electronics, when you hear the word discriminator, is it usually associated with position of targets on the screen, or with how a circuit responds to changes in frequency? • Look at the choice that mentions the local oscillator. Why would a radar set need to correct or stabilize that oscillator’s frequency?

✅ Before You Answer

• Identify which options describe target display effects (nearby objects, similar bearings) and which describe internal receiver functions. • Recall that an FM discriminator output is a voltage proportional to frequency deviation – which option matches that idea best? • Before choosing, be sure you understand what part of the radar chain a discriminator belongs to: antenna/display side or receiver/oscillator control side.