Advanced Qualification · A-005 Transmitters, modulation and processing · A-005-005-010
Quelle est la largeur de bande essentielle d'une émission FM en phonie si la fréquence de modulation est de 3 kHz et que l'excursion de fréquence est de +/- 5 kHz?
- A3 kHz
- B16 kHz
- C8 kHz
- D5 kHz
Correct answer: B — 16 kHz. Question tirée de la banque officielle d'ISDE.
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 is section A-005 of the Advanced exam: Transmitters, modulation and processing: AM, FM, SSB, keying, speech processing, and the numbers behind occupied bandwidth.
Drill A-005 — free, no account