Basic Qualification · B-003 Station assembly, practice and safety · B-003-011-005
Dans quel genre d'émission l'amplitude instantanée (l'enveloppe) du signal RF variet-elle en même temps que la modulation du signal audio?
- ALa modulation par impulsions
- BLa modulation par déplacement de fréquence
- CLa modulation d'amplitude
- DLa modulation de fréquence
Correct answer: C — La modulation d'amplitude. Question tirée de la banque officielle d'ISDE.
Why
Amplitude modulation is the correct choice because the term "amplitude" refers to the strength or height of the radio wave, and this method changes that strength to match the audio signal, creating a visible envelope that rises and falls with the voice. The full explanation — and one for every question — is in Pro.
Practise this section
Station assembly, practice and safety is section B-003 of the Basic exam: Building a station safely: power supplies, grounding, RF exposure, lightning, feedline routing, and what a transmitter, receiver and transceiver actually do.
Drill B-003 — free, no account