Feeding back into the control grids of the IF and RF amplifiers a negative DC bias which is proportioned to the average magnitude of the received carrier wave accomplished:
• Negative DC bias applied to control grids in IF (intermediate frequency) and RF (radio frequency) amplifiers • How a receiver keeps the audio output level fairly constant when signal strength changes • Distinguishing between circuit action (gain control) vs. physical effects like refraction
• Ask yourself: if the feedback voltage follows the average carrier strength, what effect does that have on the gain of the RF/IF stages when a strong signal is received vs. a weak signal? • Which choice describes a system that automatically adjusts the receiver’s gain or loudness so strong stations don’t blast and weak ones are still audible? • Look at each option: which ones are electronic control functions inside a receiver, and which ones describe unrelated phenomena (like wave bending or cancelling oscillations)?
• Identify which option refers to a feature that keeps output sound level more uniform despite changing input signal strength. • Eliminate any answer that describes wave bending in the atmosphere or cancellation of unwanted oscillations between stages, since those are different concepts. • Confirm that the correct choice involves a feedback-derived DC control voltage applied to amplifier grids to alter their gain.
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