Basic Qualification · B-003 Station assembly, practice and safety · B-003-010-004
What is the function of automatic gain control (AGC) in a receiver?
- A Maximize overall gain for greater sensitivity
- B Limit the change in volume due to large signal strength variations
- C Remove high-amplitude short-duration noise pulses
- D Improve the signal-to-distortion ratio of the detector
Correct answer: B — Limit the change in volume due to large signal strength variations. From the official ISED question bank, verified word for word.
Why
Automatic gain control acts like a volume stabilizer that automatically turns the receiver's gain down when a strong signal arrives and turns it back up when the signal fades, keeping the audio output steady despite large changes in signal strength. The full explanation — and one for every question — is in Pro.
Practise this section
Building a station safely: power supplies, grounding, RF exposure, lightning, feedline routing, and what a transmitter, receiver and transceiver actually do.