🔍 Key Concepts

• Low-pass filter purpose in electronics (what it passes, what it blocks) • Typical locations of filters inside a superheterodyne radio receiver • Differences between signal-processing stages (RF/oscillator/IF) and power supply/AVC circuits

💭 Think About

• Think about which parts of a radio receiver need to remove higher-frequency noise or ripple while allowing DC or low-frequency components to pass. • Ask yourself: where in the receiver do we mainly care about getting a clean, steady DC voltage rather than an RF signal? • Consider whether an oscillator stage wants to "smooth out" frequencies or deliberately create/maintain a specific RF frequency.

✅ Before You Answer

• Be clear on the definition of a low-pass filter: what kind of frequencies does it attenuate? • Identify which choice(s) involve circuits that carry DC power versus those that handle RF/oscillator signals. • Verify in your study material where low-pass filters are commonly drawn in receiver block diagrams, especially around the power supply and control (AVC) sections.