Extra exam question E2E09
Subelement E2, OPERATING PROCEDURES· Group E2E
E2E09
Which of the following HF digital modes uses variable-length character coding?
- A.RTTY
- B.PACTOR
- C.MT63
- D.PSK31 (correct answer)
WhyPSK31 uses a variable-length character coding scheme called Varicode. PSK31 uses a variable-length character encoding scheme called Varicode, where more frequently used characters get shorter codes, which helps keep its overall data rate and bandwidth extremely low, answer D. RTTY, PACTOR, and MT63 all use fixed-length or otherwise different coding schemes rather than Varicode's variable-length approach.
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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