Basic Qualification · B-003 Station assembly, practice and safety · B-003-010-001

Which series of emission modes listed below is in order from the narrowest bandwidth to the widest bandwidth?

  1. A FM voice, SSB voice and CW
  2. B SSB voice, CW and FM voice
  3. C CW, SSB voice and FM voice
  4. D CW, FM voice and SSB voice

Correct answer: C — CW, SSB voice and FM voice. From the official ISED question bank, verified word for word.

Why

CW, or continuous wave, uses the least space because it sends simple on-off pulses. The full explanation — and one for every question — is in Pro.

Practise this section

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 · All B-003 questions