What is the purpose of the notch filter found on many HF transceivers?
BTo reduce interference from carriers in the receiver passband
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Subelement G4 question review
All 60 official questions with the exact winning phrase marked.
What is the benefit of using the opposite or “reverse” sideband when receiving CW?
CIt may be possible to reduce or eliminate interference from other signals
How does a noise blanker work?
CBy reducing receiver gain during a noise pulse
What is the effect on plate current of the correct setting of a vacuum-tube RF power amplifier’s TUNE control?
BA pronounced dip
Why is automatic level control (ALC) used with an RF power amplifier?
CTo prevent excessive drive
What is the purpose of an antenna tuner?
CIncrease power transfer from the transmitter to the feed line
What happens as a receiver’s noise reduction control level is increased?
AReceived signals may become distorted
What is the correct adjustment for the LOAD or COUPLING control of a vacuum tube RF power amplifier?
DDesired power output without exceeding maximum allowable plate current
What is the purpose of delaying RF output after activating a transmitter’s keying line to an external amplifier?
CTo allow time for the amplifier to switch the antenna between the transceiver and the amplifier output
What is the function of an electronic keyer?
BAutomatic generation of dots and dashes for CW operation
Why should the ALC system be inactive when transmitting AFSK data signals?
BThe ALC action distorts the signal
Which of the following is a common use of the dual-VFO feature on a transceiver?
CTo transmit on one frequency and listen on another
What is the purpose of using a receive attenuator?
ATo prevent receiver overload from strong incoming signals
What item of test equipment contains horizontal and vertical channel amplifiers?
DAn oscilloscope
Which of the following is an advantage of an oscilloscope versus a digital voltmeter?
DComplex waveforms can be measured
Which of the following is the best instrument to use for checking the keying waveform of a CW transmitter?
AAn oscilloscope
What signal source is connected to the vertical input of an oscilloscope when checking the RF envelope pattern of a transmitted signal?
DThe attenuated RF output of the transmitter
Why do voltmeters have high input impedance?
DIt decreases the loading on circuits being measured
What is an advantage of a digital multimeter as compared to an analog multimeter?
CHigher precision
What signals are used to conduct a two-tone test?
BTwo non-harmonically related audio signals
What transmitter performance parameter does a two-tone test analyze?
ALinearity
When is an analog multimeter preferred to a digital multimeter?
DWhen adjusting circuits for maximum or minimum values
Which of the following can be determined with a directional wattmeter?
AStanding wave ratio
Which of the following must be connected to an antenna analyzer when it is being used for SWR measurements?
CAntenna and feed line
What effect can strong signals from nearby transmitters have on an antenna analyzer?
BReceived power that interferes with SWR readings
Which of the following can be measured with an antenna analyzer?
CImpedance of coaxial cable
Which of the following might be useful in reducing RF interference to audio frequency circuits?
BBypass capacitor
Which of the following could be a cause of interference covering a wide range of frequencies?
CArcing at a poor electrical connection
What sound is heard from an audio device experiencing RF interference from a single sideband phone transmitter?
CDistorted speech
What sound is heard from an audio device experiencing RF interference from a CW transmitter?
AOn-and-off humming or clicking
What is a possible cause of high voltages that produce RF burns?
DThe ground wire has high impedance on that frequency
What is a possible effect of a resonant ground connection?
CHigh RF voltages on the enclosures of station equipment
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
Which of the following would reduce RF interference caused by common-mode current on an audio cable?
APlace a ferrite choke on the cable
How can the effects of ground loops be minimized?
DBond equipment enclosures together
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
What technique helps to minimize RF “hot spots” in an amateur station?
CBonding all equipment enclosures together
Why must all metal enclosures of station equipment be grounded?
DIt ensures that hazardous voltages cannot appear on the chassis
What is the purpose of a speech processor in a transceiver?
AIncrease the apparent loudness of transmitted voice signals
How does a speech processor affect a single sideband phone signal?
BIt increases average power
What is the effect of an incorrectly adjusted speech processor?
DAll these choices are correct
What does an S meter measure?
CReceived signal strength
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?
DIt is 100 times more powerful
How much change in signal strength is typically represented by one S unit?
A6 dB
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?
CApproximately 4 times
What frequency range is occupied by a 3 kHz LSB signal when the displayed carrier frequency is set to 7.178 MHz?
C7.175 MHz to 7.178 MHz
What frequency range is occupied by a 3 kHz USB signal with the displayed carrier frequency set to 14.347 MHz?
B14.347 MHz to 14.350 MHz
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
How close to the upper edge of a band’s phone segment should your displayed carrier frequency be when using 3 kHz wide USB?
BAt least 3 kHz below the edge of the band
What is the purpose of a capacitance hat on a mobile antenna?
CTo electrically lengthen a physically short antenna
What is the purpose of a corona ball on an HF mobile antenna?
DTo reduce RF voltage discharge from the tip of the antenna while transmitting
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
Why should DC power for a 100-watt HF transceiver not be supplied by a vehicle’s auxiliary power socket?
BThe socket’s wiring may be inadequate for the current drawn by the transceiver
Which of the following most limits an HF mobile installation?
CEfficiency of the electrically short antenna
What is one disadvantage of using a shortened mobile antenna as opposed to a full-size antenna?
COperating bandwidth may be very limited
Which of the following may cause receive interference to an HF transceiver installed in a vehicle?
DAll these choices are correct
In what configuration are the individual cells in a solar panel connected together?
ASeries-parallel
What is the approximate open-circuit voltage from a fully illuminated silicon photovoltaic cell?
B0.5 VDC
Why should a series diode be connected between a solar panel and a storage battery that is being charged by the panel?
BTo prevent discharge of the battery through the panel during times of low or no illumination
What precaution should be taken when connecting a solar panel to a lithium iron phosphate battery?
DThe solar panel must have a charge controller