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