G4 Questions
55 questions in this subelement. Click any question ID for more details.
Answer: C
What is the benefit of using the opposite or “reverse” sideband when receiving CW?
AInterference from impulse noise will be eliminated
BMore stations can be accommodated within a given signal passband
CIt may be possible to reduce or eliminate interference from other signals
DAccidental out-of-band operation can be prevented
Answer: C
How does a noise blanker work?
ABy temporarily increasing received bandwidth
BBy redirecting noise pulses into a filter capacitor
CBy reducing receiver gain during a noise pulse
DBy clipping noise peaks
Answer: B
What is the effect on plate current of the correct setting of a vacuum-tube RF power amplifier’s TUNE control?
AA pronounced peak
BA pronounced dip
CNo change will be observed
DA slow, rhythmic oscillation
Answer: C
Why is automatic level control (ALC) used with an RF power amplifier?
ATo balance the transmitter audio frequency response
BTo reduce harmonic radiation
CTo prevent excessive drive
DTo increase overall efficiency
Answer: C
What is the purpose of an antenna tuner?
AReduce the SWR in the feed line to the antenna
BReduce the power dissipation in the feedline to the antenna
CIncrease power transfer from the transmitter to the feed line
DAll these choices are correct
Answer: A
What happens as a receiver’s noise reduction control level is increased?
AReceived signals may become distorted
BReceived frequency may become unstable
CCW signals may become severely attenuated
DReceived frequency may shift several kHz
Answer: D
What is the correct adjustment for the LOAD or COUPLING control of a vacuum tube RF power amplifier?
AMinimum SWR on the antenna
BMinimum plate current without exceeding maximum allowable grid current
CHighest plate voltage while minimizing grid current
DDesired power output without exceeding maximum allowable plate current
Answer: C
What is the purpose of delaying RF output after activating a transmitter’s keying line to an external amplifier?
ATo prevent key clicks on CW
BTo prevent transient overmodulation
CTo allow time for the amplifier to switch the antenna between the transceiver and the amplifier output
DTo allow time for the amplifier power supply to reach operating level
Answer: B
What is the function of an electronic keyer?
AAutomatic transmit/receive switching
BAutomatic generation of dots and dashes for CW operation
CTo allow time for switching the antenna from the receiver to the transmitter
DComputer interface for PSK and RTTY operation
Answer: B
Why should the ALC system be inactive when transmitting AFSK data signals?
AALC will invert the modulation of the AFSK mode
BThe ALC action distorts the signal
CWhen using digital modes, too much ALC activity can cause the transmitter to overheat
DAll these choices are correct
Answer: C
Which of the following is a common use of the dual-VFO feature on a transceiver?
ATo allow transmitting on two frequencies at once
BTo permit full duplex operation -- that is, transmitting and receiving at the same time
CTo transmit on one frequency and listen on another
DTo improve frequency accuracy by allowing variable frequency output (VFO) operation
Answer: A
What is the purpose of using a receive attenuator?
ATo prevent receiver overload from strong incoming signals
BTo reduce the transmitter power when driving a linear amplifier
CTo reduce power consumption when operating from batteries
DTo reduce excessive audio level on strong signals
Answer: D
Which of the following is an advantage of an oscilloscope versus a digital voltmeter?
AAn oscilloscope uses less power
BComplex impedances can be easily measured
CGreater precision
DComplex waveforms can be measured
Answer: A
Which of the following is the best instrument to use for checking the keying waveform of a CW transmitter?
AAn oscilloscope
BA field strength meter
CA sidetone monitor
DA wavemeter
Answer: D
What signal source is connected to the vertical input of an oscilloscope when checking the RF envelope pattern of a transmitted signal?
AThe local oscillator of the transmitter
BAn external RF oscillator
CThe transmitter balanced mixer output
DThe attenuated RF output of the transmitter
Answer: D
Why do voltmeters have high input impedance?
AIt improves the frequency response
BIt allows for higher voltages to be safely measured
CIt improves the resolution of the readings
DIt decreases the loading on circuits being measured
Answer: C
What is an advantage of a digital multimeter as compared to an analog multimeter?
ABetter for measuring computer circuits
BLess prone to overload
CHigher precision
DFaster response
Answer: B
What signals are used to conduct a two-tone test?
ATwo audio signals of the same frequency shifted 90 degrees
BTwo non-harmonically related audio signals
CTwo swept frequency tones
DTwo audio frequency range square wave signals of equal amplitude
Answer: A
What transmitter performance parameter does a two-tone test analyze?
ALinearity
BPercentage of suppression of the carrier and undesired sideband for SSB
CPercentage of frequency modulation
DPercentage of carrier phase shift
Answer: D
When is an analog multimeter preferred to a digital multimeter?
AWhen testing logic circuits
BWhen high precision is desired
CWhen measuring the frequency of an oscillator
DWhen adjusting circuits for maximum or minimum values
Answer: A
Which of the following can be determined with a directional wattmeter?
AStanding wave ratio
BAntenna front-to-back ratio
CRF interference
DRadio wave propagation
Answer: C
Which of the following must be connected to an antenna analyzer when it is being used for SWR measurements?
AReceiver
BTransmitter
CAntenna and feed line
DAll these choices are correct
Answer: B
What effect can strong signals from nearby transmitters have on an antenna analyzer?
ADesensitization which can cause intermodulation products which interfere with impedance readings
BReceived power that interferes with SWR readings
CGeneration of harmonics which interfere with frequency readings
DAll these choices are correct
Answer: C
Which of the following can be measured with an antenna analyzer?
AFront-to-back ratio of an antenna
BPower output from a transmitter
CImpedance of coaxial cable
DGain of a directional antenna
Answer: C
Which of the following could be a cause of interference covering a wide range of frequencies?
ANot using a balun or line isolator to feed balanced antennas
BLack of rectification of the transmitter’s signal in power conductors
CArcing at a poor electrical connection
DUsing a balun to feed an unbalanced antenna
Answer: C
What sound is heard from an audio device experiencing RF interference from a single sideband phone transmitter?
AA steady hum whenever the transmitter is on the air
BOn-and-off humming or clicking
CDistorted speech
DClearly audible speech
Answer: A
What sound is heard from an audio device experiencing RF interference from a CW transmitter?
AOn-and-off humming or clicking
BA CW signal at a nearly pure audio frequency
CA chirpy CW signal
DSeverely distorted audio
Answer: D
What is a possible cause of high voltages that produce RF burns?
AFlat braid rather than round wire has been used for the ground wire
BInsulated wire has been used for the ground wire
CThe ground rod is resonant
DThe ground wire has high impedance on that frequency
Answer: C
What is a possible effect of a resonant ground connection?
AOverheating of ground straps
BCorrosion of the ground rod
CHigh RF voltages on the enclosures of station equipment
DA ground loop
Answer: A
Why should soldered joints not be used in lightning protection ground connections?
AA soldered joint will likely be destroyed by the heat of a lightning strike
BSolder flux will prevent a low conductivity connection
CSolder has too high a dielectric constant to provide adequate lightning protection
DAll these choices are correct
Answer: A
Which of the following would reduce RF interference caused by common-mode current on an audio cable?
APlace a ferrite choke on the cable
BConnect the center conductor to the shield of all cables to short circuit the RFI signal
CGround the center conductor of the audio cable causing the interference
DAdd an additional insulating jacket to the cable
Answer: D
How can the effects of ground loops be minimized?
AConnect all ground conductors in series
BConnect the AC neutral conductor to the ground wire
CAvoid using lock washers and star washers when making ground connections
DBond equipment enclosures together
Answer: A
What could be a symptom caused by a ground loop in your station’s audio connections?
AYou receive reports of “hum” on your station’s transmitted signal
BThe SWR reading for one or more antennas is suddenly very high
CAn item of station equipment starts to draw excessive amounts of current
DYou receive reports of harmonic interference from your station
Answer: C
What technique helps to minimize RF “hot spots” in an amateur station?
ABuilding all equipment in a metal enclosure
BUsing surge suppressor power outlets
CBonding all equipment enclosures together
DPlacing low-pass filters on all feed lines
Answer: D
Why must all metal enclosures of station equipment be grounded?
AIt prevents a blown fuse in the event of an internal short circuit
BIt prevents signal overload
CIt ensures that the neutral wire is grounded
DIt ensures that hazardous voltages cannot appear on the chassis
Answer: B
How does a speech processor affect a single sideband phone signal?
AIt increases peak power
BIt increases average power
CIt reduces harmonic distortion
DIt reduces intermodulation distortion
Answer: D
What is the effect of an incorrectly adjusted speech processor?
ADistorted speech
BExcess intermodulation products
CExcessive background noise
DAll these choices are correct
Answer: C
What does an S meter measure?
ACarrier suppression
BImpedance
CReceived signal strength
DTransmitter power output
Answer: D
How does a signal that reads 20 dB over S9 compare to one that reads S9 on a receiver, assuming a properly calibrated S meter?
AIt is 10 times less powerful
BIt is 20 times less powerful
CIt is 20 times more powerful
DIt is 100 times more powerful
Answer: A
How much change in signal strength is typically represented by one S unit?
A6 dB
B12 dB
C15 dB
D18 dB
Answer: C
How much must the power output of a transmitter be raised to change the S meter reading on a distant receiver from S8 to S9?
AApproximately 1.5 times
BApproximately 2 times
CApproximately 4 times
DApproximately 8 times
Answer: C
What frequency range is occupied by a 3 kHz LSB signal when the displayed carrier frequency is set to 7.178 MHz?
A7.178 MHz to 7.181 MHz
B7.178 MHz to 7.184 MHz
C7.175 MHz to 7.178 MHz
D7.1765 MHz to 7.1795 MHz
Answer: B
What frequency range is occupied by a 3 kHz USB signal with the displayed carrier frequency set to 14.347 MHz?
A14.347 MHz to 14.647 MHz
B14.347 MHz to 14.350 MHz
C14.344 MHz to 14.347 MHz
D14.3455 MHz to 14.3485 MHz
Answer: A
How close to the lower edge of a band’s phone segment should your displayed carrier frequency be when using 3 kHz wide LSB?
AAt least 3 kHz above the edge of the segment
BAt least 3 kHz below the edge of the segment
CAt least 1 kHz below the edge of the segment
DAt least 1 kHz above the edge of the segment
Answer: B
How close to the upper edge of a band’s phone segment should your displayed carrier frequency be when using 3 kHz wide USB?
AAt least 3 kHz above the edge of the band
BAt least 3 kHz below the edge of the band
CAt least 1 kHz above the edge of the segment
DAt least 1 kHz below the edge of the segment
Answer: D
What is the purpose of a corona ball on an HF mobile antenna?
ATo narrow the operating bandwidth of the antenna
BTo increase the “Q” of the antenna
CTo reduce the chance of damage if the antenna should strike an object
DTo reduce RF voltage discharge from the tip of the antenna while transmitting
Answer: A
Which of the following direct, fused power connections would be the best for a 100-watt HF mobile installation?
ATo the battery using heavy-gauge wire
BTo the alternator or generator using heavy-gauge wire
CTo the battery using insulated heavy duty balanced transmission line
DTo the alternator or generator using insulated heavy duty balanced transmission line
Answer: B
Why should DC power for a 100-watt HF transceiver not be supplied by a vehicle’s auxiliary power socket?
AThe socket is not wired with an RF-shielded power cable
BThe socket’s wiring may be inadequate for the current drawn by the transceiver
CThe DC polarity of the socket is reversed from the polarity of modern HF transceivers
DDrawing more than 50 watts from this socket could cause the engine to overheat
Answer: C
Which of the following most limits an HF mobile installation?
A“Picket fencing”
BThe wire gauge of the DC power line to the transceiver
CEfficiency of the electrically short antenna
DFCC rules limiting mobile output power on the 75-meter band
Answer: C
What is one disadvantage of using a shortened mobile antenna as opposed to a full-size antenna?
AShort antennas are more likely to cause distortion of transmitted signals
BQ of the antenna will be very low
COperating bandwidth may be very limited
DHarmonic radiation may increase
Answer: D
Which of the following may cause receive interference to an HF transceiver installed in a vehicle?
AThe battery charging system
BThe fuel delivery system
CThe control computers
DAll these choices are correct
Answer: A
In what configuration are the individual cells in a solar panel connected together?
ASeries-parallel
BShunt
CBypass
DFull-wave bridge
Answer: B
What is the approximate open-circuit voltage from a fully illuminated silicon photovoltaic cell?
A0.02 VDC
B0.5 VDC
C0.2 VDC
D1.38 VDC
Answer: B
Why should a series diode be connected between a solar panel and a storage battery that is being charged by the panel?
ATo prevent overload by regulating the charging voltage
BTo prevent discharge of the battery through the panel during times of low or no illumination
CTo limit the current flowing from the panel to a safe value
DTo prevent damage to the battery due to excessive voltage at high illumination levels
Answer: D
What precaution should be taken when connecting a solar panel to a lithium iron phosphate battery?
AGround the solar panel outer metal framework
BEnsure the battery is placed terminals-up
CA series resistor must be in place
DThe solar panel must have a charge controller