General exam question G4C04
Subelement G4, AMATEUR RADIO PRACTICES· Group G4C
What sound is heard from an audio device experiencing RF interference from a CW transmitter?
- A.On-and-off humming or clicking (correct answer)
- B.A CW signal at a nearly pure audio frequency
- C.A chirpy CW signal
- D.Severely distorted audio
WhyAn audio device experiencing RF interference from a CW transmitter produces on-and-off humming or clicking. A CW transmitter's on/off keyed carrier, when it leaks into an audio device and gets rectified by a nonlinear junction there, reproduces as on-and-off humming or clicking that tracks the keying, answer A. It doesn't sound like a pure audio tone, a chirpy CW note (that describes an unstable oscillator, not interference symptoms), or severely distorted audio, those describe other interference sources.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2023-2027 NCVEC Element 3 pool (public domain); the explanation above is original writing, see our methodology.
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