Extra exam question E8D09
Subelement E8, SIGNALS AND EMISSIONS· Group E8D
What is considered an acceptable maximum IMD level for an idling PSK signal?
- A.+5 dB
- B.+10 dB
- C.+15 dB
- D.-30 dB (correct answer)
WhyAn acceptable maximum IMD level for an idling PSK signal is considered to be -30 dB. An acceptable maximum IMD level for an idling PSK signal is generally considered to be -30 dB relative to the desired signal, keeping unwanted distortion products well suppressed even when the transmitter is sending idle characters, answer D. The positive dB figures listed would actually represent distortion products stronger than, or barely below, the main signal, far worse than what's considered acceptable.
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.
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