Advanced Qualification · A-005 Transmitters, modulation and processing · A-005-005-010
What is the significant bandwidth of an FM-phone transmission having a +/- 5-kHz deviation and a 3-kHz modulating frequency?
- A 5 kHz
- B 3 kHz
- C 16 kHz
- D 8 kHz
Correct answer: C — 16 kHz. From the official ISED question bank, verified word for word.
Why
The significant bandwidth is 16 kHz because you must account for the total swing of the signal, which includes both the maximum frequency shift and the speed of the audio tone. 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.