G8 – SIGNALS AND EMISSIONS [3 Exam Questions – 3 Groups] Flashcards
How is an FSK signal generated?
A. By keying an FM transmitter with a sub-audible tone
B. By changing an oscillator’s frequency directly with a digital control signal
C. By using a transceiver’s computer data interface protocol to change frequencies
D. By reconfiguring the CW keying input to act as a tone generator
G8A01 (B)
B. By changing an oscillator’s frequency directly with a digital control signal
What is the name of the process that changes the phase angle of an RF signal to convey information?
A. Phase convolution
B. Phase modulation
C. Phase transformation
D. Phase inversion
G8A02 (B)
B. Phase modulation
What is the name of the process that changes the instantaneous frequency of an RF wave to convey information?
A. Frequency convolution
B. Frequency transformation
C. Frequency conversion
D. Frequency modulation
G8A03 (D)
D. Frequency modulation
What emission is produced by a reactance modulator connected to a transmitter RF amplifier stage?
A. Multiplex modulation
B. Phase modulation
C. Amplitude modulation
D. Pulse modulation
G8A04 (B)
B. Phase modulation
What type of modulation varies the instantaneous power level of the RF signal?
A. Frequency shift keying
B. Phase modulation
C. Frequency modulation
D. Amplitude modulation
G8A05 (D)
D. Amplitude modulation
Which of the following is characteristic of QPSK31?
A. It is sideband sensitive
B. It has forward error correction
C. The bandwidth is slightly higher than BPSK31
D. All these choices are correct
G8A06 (C)
C. The bandwidth is slightly higher than BPSK31
Which of the following phone emissions uses the narrowest bandwidth?
A. Single sideband
B. Double sideband
C. Phase modulation
D. Frequency modulation
G8A07 (A)
A. Single sideband
Which of the following is an effect of overmodulation?
A. Insufficient audio
B. Insufficient bandwidth
C. Frequency drift
D. Excessive bandwidth
G8A08 (D)
D. Excessive bandwidth
What type of modulation is used by the FT8 digital mode?
A. 8-tone frequency shift keying
B. Vestigial sideband
C. Amplitude compressed AM
D. Direct sequence spread spectrum
G8A09 (A)
A. 8-tone frequency shift keying
What is meant by the term “flat-topping,” when referring to a single sideband phone transmission?
A. Signal distortion caused by insufficient collector current
B. The transmitter’s automatic level control (ALC) is properly adjusted
C. Signal distortion caused by excessive drive
D. The transmitter’s carrier is properly suppressed
G8A10 (C)
C. Signal distortion caused by excessive drive
What is the modulation envelope of an AM signal?
A. The waveform created by connecting the peak values of the modulated signal
B. The carrier frequency that contains the signal
C. Spurious signals that envelop nearby frequencies
D. The bandwidth of the modulated signal
G8A11 (A)
A. The waveform created by connecting the peak values of the modulated signal
Which of the following narrow-band digital modes can receive signals with very low signal-to-noise ratios?
A. MSK144
B. FT8
C. AMTOR
D. MFSK32
G8A12 (B)
B. FT8
Which mixer input is varied or tuned to convert signals of different frequencies to an intermediate frequency (IF)?
A. Image frequency
B. Local oscillator
C. RF input
D. Beat frequency oscillator
G8B01 (B)
B. Local oscillator
If a receiver mixes a 13.800 MHz VFO with a 14.255 MHz received signal to produce a 455 kHz intermediate frequency (IF) signal, what type of interference will a 13.345 MHz signal produce in the receiver?
A. Quadrature noise
B. Image response
C. Mixer interference
D. Intermediate interference
G8B02 (B)
B. Image response
What is another term for the mixing of two RF signals?
A. Heterodyning
B. Synthesizing
C. Cancellation
D. Phase inverting
G8B03 (A)
A. Heterodyning