Extra-Study/pages/E2E.md

E2E Operating methods: digital modes and procedures for HF

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