Advanced Qualification · A-005 Transmitters, modulation and processing · A-005-007-001
Maintaining the peak RF output of a SSB transmitter at a relatively constant level requires a circuit called the:
- A automatic level control (ALC)
- B automatic gain control (AGC)
- C automatic output control (AOC)
- D automatic volume control (AVC)
Correct answer: A — automatic level control (ALC). From the official ISED question bank, verified word for word.
Why
Automatic level control (ALC) keeps the peak radio frequency output of a single-sideband transmitter steady by reducing the audio input when the signal gets too loud, preventing distortion and protecting the final amplifier. The full explanation — and one for every question — is in Pro.
Practise this section
Transmitters, modulation and processing: AM, FM, SSB, keying, speech processing, and the numbers behind occupied bandwidth.