Extra exam question E8D04
Subelement E8, SIGNALS AND EMISSIONS· Group E8D
What is the primary effect of extremely short rise or fall time on a CW signal?
- A.More difficult to copy
- B.The generation of RF harmonics
- C.The generation of key clicks (correct answer)
- D.More difficult to tune
WhyAn extremely short rise or fall time on a CW signal primarily generates key clicks. An extremely short rise or fall time on a CW signal's keying waveform generates key clicks, audible broadband thumps at the start and end of each dit and dah caused by that abrupt transition spreading energy well outside the signal's intended narrow bandwidth, answer C. It doesn't primarily make the signal harder to copy or tune, and while sharp transitions can generate some harmonic content, key clicks specifically (broadband transient noise at the edges of each element) is the characteristic, well-known effect of overly fast keying transitions.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2024-2028 NCVEC Element 4 pool (public domain); the explanation above is original writing, see our methodology.
Related questions
- E8D01Why are received spread spectrum signals resistant to interference?
- E8D02What spread spectrum communications technique uses a high-speed binary bit stream to shift the phase of an RF carrier?
- E8D03Which describes spread spectrum frequency hopping?
- E8D05What is the most common method of reducing key clicks?
- E8D06What is the advantage of including parity bits in ASCII characters?