81 lines
3.0 KiB
Markdown
81 lines
3.0 KiB
Markdown
E2E Operating methods: digital modes and procedures for HF
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- [[E2E01]] (B)
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Which of the following types of modulation is used for data emissions below 30 MHz? #card
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- [[A.]] DTMF tones modulating an FM signal
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- [[B.]] FSK
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- [[C.]] Pulse modulation
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- [[D.]] Spread spectrum
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- [[E2E02]] (B)
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Which of the following synchronizes WSJT-X digital mode transmit/receive timing? #card
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- [[A.]] Alignment of frequency shifts
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- [[B.]] Synchronization of computer clocks
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- [[C.]] Sync-field transmission
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- [[D.]] Sync-pulse timing
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- [[E2E03]] (B)
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To what does the "4" in FT4 refer? #card
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- [[A.]] Multiples of 4 bits of user information
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- [[B.]] Four-tone continuous-phase frequency shift keying
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- [[C.]] Four transmit/receive cycles per minute
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- [[D.]] All these choices are correct
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- [[E2E04]] (D)
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Which of the following is characteristic of the FST4 mode? #card
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- [[A.]] Four-tone Gaussian frequency shift keying
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- [[B.]] Variable transmit/receive periods
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- [[C.]] Seven different tone spacings
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- [[D.]] All these choices are correct
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- [[E2E05]] (A)
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Which of these digital modes does not support keyboard-to-keyboard operation? #card
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- [[A.]] WSPR
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- [[B.]] RTTY
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- [[C.]] PSK31
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- [[D.]] MFSK16
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- [[E2E06]] (C)
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What is the length of an FT8 transmission cycle? #card
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- [[A.]] It varies with the amount of data
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- [[B.]] 8 seconds
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- [[C.]] 15 seconds
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- [[D.]] 30 seconds
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- [[E2E07]] (C)
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How does Q65 differ from JT65? #card
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- [[A.]] Keyboard-to keyboard operation is supported
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- [[B.]] Quadrature modulation is used
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- [[C.]] Multiple receive cycles are averaged
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- [[D.]] All these choices are correct
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- [[E2E08]] (B)
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Which of the following HF digital modes can be used to transfer binary files? #card
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- [[A.]] PSK31
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- [[B.]] PACTOR
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- [[C.]] RTTY
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- [[D.]] AMTOR
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- [[E2E09]] (D)
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Which of the following HF digital modes uses variable-length character coding? #card
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- [[A.]] RTTY
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- [[B.]] PACTOR
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- [[C.]] MT63
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- [[D.]] PSK31
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- [[E2E10]] (C)
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Which of these digital modes has the narrowest bandwidth? #card
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- [[A.]] MFSK16
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- [[B.]] 170 Hz shift, 45-baud RTTY
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- [[C.]] FT8
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- [[D.]] PACTOR IV
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- [[E2E11]] (A)
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What is the difference between direct FSK and audio FSK? #card
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- [[A.]] Direct FSK modulates the transmitter VFO
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- [[B.]] Direct FSK occupies less bandwidth
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- [[C.]] Direct FSK can transmit higher baud rates
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- [[D.]] All these choices are correct
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- [[E2E12]] (A)
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How do ALE stations establish contact? #card
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- [[A.]] ALE constantly scans a list of frequencies, activating the radio when the designated call sign is received
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- [[B.]] ALE radios monitor an internet site for the frequency they are being paged on
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- [[C.]] ALE radios send a constant tone code to establish a frequency for future use
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- [[D.]] ALE radios activate when they hear their signal echoed by back scatter
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- [[E2E13]] (D)
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Which of these digital modes has the highest data throughput under clear communication conditions? #card
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- [[A.]] MFSK16
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- [[B.]] 170 Hz shift, 45 baud RTTY
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- [[C.]] FT8
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- [[D.]] PACTOR IV
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