Advanced Qualification · A-005 Transmitters, modulation and processing · A-005-006-006
What audio shaping network is added at an FM transmitter to attenuate the lower audio frequencies?
- A An audio prescaler
- B A heterodyne suppressor
- C A de-emphasis network
- D A pre-emphasis network
Correct answer: D — A pre-emphasis network. From the official ISED question bank, verified word for word.
Why
A pre-emphasis network boosts higher audio frequencies before transmission to make them stronger than lower ones, which helps overcome noise that naturally affects high pitches more. 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.