🔍 Key Concepts

• Double-sideband (DSB) vs single-sideband (SSB) modulation • How amplitude modulation (AM) is created in a transmitter • Which circuits mainly change frequency/phase vs those that change amplitude

💭 Think About

• Which method directly causes the RF carrier’s amplitude to follow the audio (voice) signal? • Which options are more associated with frequency or phase modulation rather than amplitude modulation? • In a typical high‑level AM transmitter, where is the supply voltage being varied to create modulation?

✅ Before You Answer

• Identify which choices mainly control frequency or phase instead of amplitude – those are not producing DSB AM. • Recall that standard AM voice (phone) with both sidebands is created by varying the amplitude of the RF carrier with the audio signal. • Check which option specifically changes the amplitude of the RF power stage rather than its frequency.