Basic Qualification · B-003 Station assembly, practice and safety · B-003-005-009
In an SSB/CW receiver, what is the purpose of the audio frequency (AF) amplifier?
- A Convert audio frequency electrical signals into sound
- B Increase the BFO signal for driving the product detector
- C Provide audible warning of receiver overload
- D Increase the level of the recovered modulation
Correct answer: D — Increase the level of the recovered modulation. From the official ISED question bank, verified word for word.
Why
The audio frequency amplifier boosts the weak electrical signal that has already been converted from radio waves into sound information, making it strong enough to drive your speaker or headphones. 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.