SignalPrep
Basic Qualification · B-003 Station assembly, practice and safety · B-003-004-004

In a basic three-stage CW transmitter, what does the key do?

  1. AIt reduces key chirps
  2. BIt controls the amplitude of the carrier
  3. CIt switches the oscillator on and off
  4. DIt reduces key clicks

Correct answer: B — It controls the amplitude of the carrier. From the official ISED question bank, verified word for word.

Why

In a continuous wave transmitter, the radio wave is always being generated, so the Morse code signal is created by turning that steady wave on and off. 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

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