G8 Questions
40 questions in this subelement. Click any question ID for more details.
Answer: B
What is the name of the process that changes the phase angle of an RF signal to convey information?
APhase convolution
BPhase modulation
CPhase transformation
DPhase inversion
Answer: D
What is the name of the process that changes the instantaneous frequency of an RF wave to convey information?
AFrequency convolution
BFrequency transformation
CFrequency conversion
DFrequency modulation
Answer: B
What emission is produced by a reactance modulator connected to a transmitter RF amplifier stage?
AMultiplex modulation
BPhase modulation
CAmplitude modulation
DPulse modulation
Answer: D
What type of modulation varies the instantaneous power level of the RF signal?
APower modulation
BPhase modulation
CFrequency modulation
DAmplitude modulation
Answer: D
Which of the following is characteristic of QPSK31?
AIt is sideband sensitive
BIts encoding provides error correction
CIts bandwidth is approximately the same as BPSK31
DAll these choices are correct
Answer: A
Which of the following phone emissions uses the narrowest bandwidth?
ASingle sideband
BVestigial sideband
CPhase modulation
DFrequency modulation
Answer: D
Which of the following is an effect of overmodulation?
AInsufficient audio
BInsufficient bandwidth
CFrequency drift
DExcessive bandwidth
Answer: A
What type of modulation is used by FT8?
A8-tone frequency shift keying
BVestigial sideband
CAmplitude compressed AM
D8-bit direct sequence spread spectrum
Answer: C
What is meant by the term “flat-topping,” when referring to an amplitude-modulated phone signal?
ASignal distortion caused by insufficient collector current
BThe transmitter’s automatic level control (ALC) is properly adjusted
CSignal distortion caused by excessive drive or speech levels
DThe transmitter’s carrier is properly suppressed
Answer: A
What is the modulation envelope of an AM signal?
AThe waveform created by connecting the peak values of the modulated signal
BThe carrier frequency that contains the signal
CSpurious signals that envelop nearby frequencies
DThe bandwidth of the modulated signal
Answer: D
What is QPSK modulation?
AModulation using quasi-parallel to serial conversion to reduce bandwidth
BModulation using quadra-pole sideband keying to generate spread spectrum signals
CModulation using Fast Fourier Transforms to generate frequencies at the first, second, third, and fourth harmonics of the carrier frequency to improve noise immunity
DModulation in which digital data is transmitted using 0-, 90-, 180- and 270-degrees phase shift to represent pairs of bits
Answer: C
What is a link budget?
AThe financial costs associated with operating a radio link
BThe sum of antenna gains minus system losses
CThe sum of transmit power and antenna gains minus system losses as seen at the receiver
DThe difference between transmit power and receiver sensitivity
Answer: B
What is link margin?
AThe opposite of fade margin
BThe difference between received power level and minimum required signal level at the input to the receiver
CTransmit power minus receiver sensitivity
DReceiver sensitivity plus 3 dB
Answer: B
What is the term for interference from a signal at twice the IF frequency from the desired signal?
AQuadrature response
BImage response
CMixer interference
DIntermediate interference
Answer: A
What is another term for the mixing of two RF signals?
AHeterodyning
BSynthesizing
CFrequency inversion
DPhase inversion
Answer: D
What is the stage in a VHF FM transmitter that generates a harmonic of a lower frequency signal to reach the desired operating frequency?
AMixer
BReactance modulator
CBalanced converter
DMultiplier
Answer: C
Which intermodulation products are closest to the original signal frequencies?
ASecond harmonics
BEven-order
COdd-order
DIntercept point
Answer: D
What is the total bandwidth of an FM phone transmission having 5 kHz deviation and 3 kHz modulating frequency?
A3 kHz
B5 kHz
C8 kHz
D16 kHz
Answer: B
What is the frequency deviation for a 12.21 MHz reactance modulated oscillator in a 5 kHz deviation, 146.52 MHz FM phone transmitter?
A101.75 Hz
B416.7 Hz
C5 kHz
D60 kHz
Answer: B
Why is it important to know the duty cycle of the mode you are using when transmitting?
ATo aid in tuning your transmitter
BSome modes have high duty cycles that could exceed the transmitter’s average power rating
CTo allow time for the other station to break in during a transmission
DTo prevent overmodulation
Answer: D
Why is it good to match receiver bandwidth to the bandwidth of the operating mode?
AIt is required by FCC rules
BIt minimizes power consumption in the receiver
CIt improves impedance matching of the antenna
DIt results in the best signal-to-noise ratio
Answer: B
What is the relationship between transmitted symbol rate and bandwidth?
ASymbol rate and bandwidth are not related
BHigher symbol rates require wider bandwidth
CLower symbol rates require wider bandwidth
DBandwidth is half the symbol rate
Answer: C
What combination of a mixer’s Local Oscillator (LO) and RF input frequencies is found in the output?
AThe ratio
BThe average
CThe sum and difference
DThe arithmetic product
Answer: A
What process combines two signals in a non-linear circuit to produce unwanted spurious outputs?
AIntermodulation
BHeterodyning
CDetection
DRolloff
Answer: C
Which of the following is an odd-order intermodulation product of frequencies F1 and F2?
A5F1-3F2
B3F1-F2
C2F1-F2
DAll these choices are correct
Answer: A
Which digital mode is used as a low-power beacon for assessing HF propagation?
AWSPR
BMFSK16
CPSK31
DSSB-SC
Answer: C
What part of a packet radio frame contains the routing and handling information?
ADirectory
BPreamble
CHeader
DTrailer
Answer: C
Which of the following describes Baudot code?
AA 7-bit code with start, stop, and parity bits
BA code using error detection and correction
CA 5-bit code with additional start and stop bits
DA code using SELCAL and LISTEN
Answer: A
In an ARQ mode, what is meant by a NAK response to a transmitted packet?
ARequest retransmission of the packet
BPacket was received without error
CReceiving station connected and ready for transmissions
DEntire file received correctly
Answer: B
What action results from a failure to exchange information due to excessive transmission attempts when using an ARQ mode?
AThe checksum overflows
BThe connection is dropped
CPackets will be routed incorrectly
DEncoding reverts to the default character set
Answer: B
Which of the following narrow-band digital modes can receive signals with very low signal-to-noise ratios?
AMSK144
BFT8
CAMTOR
DMFSK32
Answer: B
Which of the following statements is true about PSK31?
AUpper case letters are sent with more power
BUpper case letters use longer Varicode bit sequences and thus slow down transmission
CError correction is used to ensure accurate message reception
DHigher power is needed as compared to RTTY for similar error rates
Answer: B
Which is true of mesh network microwave nodes?
AHaving more nodes increases signal strengths
BIf one node fails, a packet may still reach its target station via an alternate node
CLinks between two nodes in a network may have different frequencies and bandwidths
DMore nodes reduce overall microwave out of band interference
Answer: C
How does forward error correction (FEC) allow the receiver to correct data errors?
ABy controlling transmitter output power for optimum signal strength
BBy using the Varicode character set
CBy transmitting redundant information with the data
DBy using a parity bit with each character
Answer: D
How are the two separate frequencies of a Frequency Shift Keyed (FSK) signal identified?
ADot and dash
BOn and off
CHigh and low
DMark and space
Answer: A
Which type of code is used for sending characters in a PSK31 signal?
AVaricode
BViterbi
CVolumetric
DBinary
Answer: D
What is indicated on a waterfall display by one or more vertical lines on either side of a data mode or RTTY signal?
ALong path propagation
BBackscatter propagation
CInsufficient modulation
DOvermodulation
Answer: C
Which of the following describes a waterfall display?
AFrequency is horizontal, signal strength is vertical, time is intensity
BFrequency is vertical, signal strength is intensity, time is horizontal
CFrequency is horizontal, signal strength is intensity, time is vertical
DFrequency is vertical, signal strength is horizontal, time is intensity
Answer: C
What does an FT8 signal report of +3 mean?
AThe signal is 3 times the noise level of an equivalent SSB signal
BThe signal is S3 (weak signals)
CThe signal-to-noise ratio is equivalent to +3dB in a 2.5 kHz bandwidth
DThe signal is 3 dB over S9
Answer: D
Which of the following provide digital voice modes?
AWSPR, MFSK16, and EasyPAL
BFT8, FT4, and FST4
CWinlink, PACTOR II, and PACTOR III
DDMR, D-STAR, and SystemFusion