All 60 Ham Radio General Class questions for G4 Amateur Radio Practices with the correct answers marked, from the official 2023-2027 question pool. Test yourself with the free practice exam.
G4A01
What is the purpose of the notch filter found on many HF transceivers?
A. To restrict the transmitter voice bandwidth
B. To reduce interference from carriers in the receiver passband ✓
C. To eliminate receiver interference from impulse noise sources
D. To remove interfering splatter generated by signals on adjacent frequencies
G4A02
What is the benefit of using the opposite or “reverse” sideband when receiving CW?
A. Interference from impulse noise will be eliminated
B. More stations can be accommodated within a given signal passband
C. It may be possible to reduce or eliminate interference from other signals ✓
D. Accidental out-of-band operation can be prevented
G4A03
How does a noise blanker work?
A. By temporarily increasing received bandwidth
B. By redirecting noise pulses into a filter capacitor
C. By reducing receiver gain during a noise pulse ✓
D. By clipping noise peaks
G4A04
What is the effect on plate current of the correct setting of a vacuum-tube RF power amplifier’s TUNE control?
A. A pronounced peak
B. A pronounced dip ✓
C. No change will be observed
D. A slow, rhythmic oscillation
G4A05
Why is automatic level control (ALC) used with an RF power amplifier?
A. To balance the transmitter audio frequency response
B. To reduce harmonic radiation
C. To prevent excessive drive ✓
D. To increase overall efficiency
G4A06
What is the purpose of an antenna tuner?
A. Reduce the SWR in the feed line to the antenna
B. Reduce the power dissipation in the feedline to the antenna
C. Increase power transfer from the transmitter to the feed line ✓
D. All these choices are correct
G4A07
What happens as a receiver’s noise reduction control level is increased?
A. Received signals may become distorted ✓
B. Received frequency may become unstable
C. CW signals may become severely attenuated
D. Received frequency may shift several kHz
G4A08
What is the correct adjustment for the LOAD or COUPLING control of a vacuum tube RF power amplifier?
A. Minimum SWR on the antenna
B. Minimum plate current without exceeding maximum allowable grid current
C. Highest plate voltage while minimizing grid current
D. Desired power output without exceeding maximum allowable plate current ✓
G4A09
What is the purpose of delaying RF output after activating a transmitter’s keying line to an external amplifier?
A. To prevent key clicks on CW
B. To prevent transient overmodulation
C. To allow time for the amplifier to switch the antenna between the transceiver and the amplifier output ✓
D. To allow time for the amplifier power supply to reach operating level
G4A10
What is the function of an electronic keyer?
A. Automatic transmit/receive switching
B. Automatic generation of dots and dashes for CW operation ✓
C. To allow time for switching the antenna from the receiver to the transmitter
D. Computer interface for PSK and RTTY operation
G4A11
Why should the ALC system be inactive when transmitting AFSK data signals?
A. ALC will invert the modulation of the AFSK mode
B. The ALC action distorts the signal ✓
C. When using digital modes, too much ALC activity can cause the transmitter to overheat
D. All these choices are correct
G4A12
Which of the following is a common use of the dual-VFO feature on a transceiver?
A. To allow transmitting on two frequencies at once
B. To permit full duplex operation -- that is, transmitting and receiving at the same time
C. To transmit on one frequency and listen on another ✓
D. To improve frequency accuracy by allowing variable frequency output (VFO) operation
G4A13
What is the purpose of using a receive attenuator?
A. To prevent receiver overload from strong incoming signals ✓
B. To reduce the transmitter power when driving a linear amplifier
C. To reduce power consumption when operating from batteries
D. To reduce excessive audio level on strong signals
G4B01
What item of test equipment contains horizontal and vertical channel amplifiers?
A. An ohmmeter
B. A signal generator
C. An ammeter
D. An oscilloscope ✓
G4B02
Which of the following is an advantage of an oscilloscope versus a digital voltmeter?
A. An oscilloscope uses less power
B. Complex impedances can be easily measured
C. Greater precision
D. Complex waveforms can be measured ✓
G4B03
Which of the following is the best instrument to use for checking the keying waveform of a CW transmitter?
A. An oscilloscope ✓
B. A field strength meter
C. A sidetone monitor
D. A wavemeter
G4B04
What signal source is connected to the vertical input of an oscilloscope when checking the RF envelope pattern of a transmitted signal?
A. The local oscillator of the transmitter
B. An external RF oscillator
C. The transmitter balanced mixer output
D. The attenuated RF output of the transmitter ✓
G4B05
Why do voltmeters have high input impedance?
A. It improves the frequency response
B. It allows for higher voltages to be safely measured
C. It improves the resolution of the readings
D. It decreases the loading on circuits being measured ✓
G4B06
What is an advantage of a digital multimeter as compared to an analog multimeter?
A. Better for measuring computer circuits
B. Less prone to overload
C. Higher precision ✓
D. Faster response
G4B07
What signals are used to conduct a two-tone test?
A. Two audio signals of the same frequency shifted 90 degrees
B. Two non-harmonically related audio signals ✓
C. Two swept frequency tones
D. Two audio frequency range square wave signals of equal amplitude
G4B08
What transmitter performance parameter does a two-tone test analyze?
A. Linearity ✓
B. Percentage of suppression of the carrier and undesired sideband for SSB
C. Percentage of frequency modulation
D. Percentage of carrier phase shift
G4B09
When is an analog multimeter preferred to a digital multimeter?
A. When testing logic circuits
B. When high precision is desired
C. When measuring the frequency of an oscillator
D. When adjusting circuits for maximum or minimum values ✓
G4B10
Which of the following can be determined with a directional wattmeter?
A. Standing wave ratio ✓
B. Antenna front-to-back ratio
C. RF interference
D. Radio wave propagation
G4B11
Which of the following must be connected to an antenna analyzer when it is being used for SWR measurements?
A. Receiver
B. Transmitter
C. Antenna and feed line ✓
D. All these choices are correct
G4B12
What effect can strong signals from nearby transmitters have on an antenna analyzer?
A. Desensitization which can cause intermodulation products which interfere with impedance readings
B. Received power that interferes with SWR readings ✓
C. Generation of harmonics which interfere with frequency readings
D. All these choices are correct
G4B13
Which of the following can be measured with an antenna analyzer?
A. Front-to-back ratio of an antenna
B. Power output from a transmitter
C. Impedance of coaxial cable ✓
D. Gain of a directional antenna
G4C01
Which of the following might be useful in reducing RF interference to audio frequency circuits?
A. Bypass inductor
B. Bypass capacitor ✓
C. Forward-biased diode
D. Reverse-biased diode
G4C02
Which of the following could be a cause of interference covering a wide range of frequencies?
A. Not using a balun or line isolator to feed balanced antennas
B. Lack of rectification of the transmitter’s signal in power conductors
C. Arcing at a poor electrical connection ✓
D. Using a balun to feed an unbalanced antenna
G4C03
What sound is heard from an audio device experiencing RF interference from a single sideband phone transmitter?
A. A steady hum whenever the transmitter is on the air
B. On-and-off humming or clicking
C. Distorted speech ✓
D. Clearly audible speech
G4C04
What sound is heard from an audio device experiencing RF interference from a CW transmitter?
A. On-and-off humming or clicking ✓
B. A CW signal at a nearly pure audio frequency
C. A chirpy CW signal
D. Severely distorted audio
G4C05
What is a possible cause of high voltages that produce RF burns?
A. Flat braid rather than round wire has been used for the ground wire
B. Insulated wire has been used for the ground wire
C. The ground rod is resonant
D. The ground wire has high impedance on that frequency ✓
G4C06
What is a possible effect of a resonant ground connection?
A. Overheating of ground straps
B. Corrosion of the ground rod
C. High RF voltages on the enclosures of station equipment ✓
D. A ground loop
G4C07
Why should soldered joints not be used in lightning protection ground connections?
A. A soldered joint will likely be destroyed by the heat of a lightning strike ✓
B. Solder flux will prevent a low conductivity connection
C. Solder has too high a dielectric constant to provide adequate lightning protection
D. All these choices are correct
G4C08
Which of the following would reduce RF interference caused by common-mode current on an audio cable?
A. Place a ferrite choke on the cable ✓
B. Connect the center conductor to the shield of all cables to short circuit the RFI signal
C. Ground the center conductor of the audio cable causing the interference
D. Add an additional insulating jacket to the cable
G4C09
How can the effects of ground loops be minimized?
A. Connect all ground conductors in series
B. Connect the AC neutral conductor to the ground wire
C. Avoid using lock washers and star washers when making ground connections
D. Bond equipment enclosures together ✓
G4C10
What could be a symptom caused by a ground loop in your station’s audio connections?
A. You receive reports of “hum” on your station’s transmitted signal ✓
B. The SWR reading for one or more antennas is suddenly very high
C. An item of station equipment starts to draw excessive amounts of current
D. You receive reports of harmonic interference from your station
G4C11
What technique helps to minimize RF “hot spots” in an amateur station?
A. Building all equipment in a metal enclosure
B. Using surge suppressor power outlets
C. Bonding all equipment enclosures together ✓
D. Placing low-pass filters on all feed lines
G4C12
Why must all metal enclosures of station equipment be grounded?
A. It prevents a blown fuse in the event of an internal short circuit
B. It prevents signal overload
C. It ensures that the neutral wire is grounded
D. It ensures that hazardous voltages cannot appear on the chassis ✓
G4D01
What is the purpose of a speech processor in a transceiver?
A. Increase the apparent loudness of transmitted voice signals ✓
B. Increase transmitter bass response for more natural-sounding SSB signals
C. Prevent distortion of voice signals
D. Decrease high-frequency voice output to prevent out-of-band operation
G4D02
How does a speech processor affect a single sideband phone signal?
A. It increases peak power
B. It increases average power ✓
C. It reduces harmonic distortion
D. It reduces intermodulation distortion
G4D03
What is the effect of an incorrectly adjusted speech processor?
A. Distorted speech
B. Excess intermodulation products
C. Excessive background noise
D. All these choices are correct ✓
G4D04
What does an S meter measure?
A. Carrier suppression
B. Impedance
C. Received signal strength ✓
D. Transmitter power output
G4D05
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?
A. It is 10 times less powerful
B. It is 20 times less powerful
C. It is 20 times more powerful
D. It is 100 times more powerful ✓
G4D06
How much change in signal strength is typically represented by one S unit?
A. 6 dB ✓
B. 12 dB
C. 15 dB
D. 18 dB
G4D07
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?
A. Approximately 1.5 times
B. Approximately 2 times
C. Approximately 4 times ✓
D. Approximately 8 times
G4D08
What frequency range is occupied by a 3 kHz LSB signal when the displayed carrier frequency is set to 7.178 MHz?
A. 7.178 MHz to 7.181 MHz
B. 7.178 MHz to 7.184 MHz
C. 7.175 MHz to 7.178 MHz ✓
D. 7.1765 MHz to 7.1795 MHz
G4D09
What frequency range is occupied by a 3 kHz USB signal with the displayed carrier frequency set to 14.347 MHz?
A. 14.347 MHz to 14.647 MHz
B. 14.347 MHz to 14.350 MHz ✓
C. 14.344 MHz to 14.347 MHz
D. 14.3455 MHz to 14.3485 MHz
G4D10
How close to the lower edge of a band’s phone segment should your displayed carrier frequency be when using 3 kHz wide LSB?
A. At least 3 kHz above the edge of the segment ✓
B. At least 3 kHz below the edge of the segment
C. At least 1 kHz below the edge of the segment
D. At least 1 kHz above the edge of the segment
G4D11
How close to the upper edge of a band’s phone segment should your displayed carrier frequency be when using 3 kHz wide USB?
A. At least 3 kHz above the edge of the band
B. At least 3 kHz below the edge of the band ✓
C. At least 1 kHz above the edge of the segment
D. At least 1 kHz below the edge of the segment
G4E01
What is the purpose of a capacitance hat on a mobile antenna?
A. To increase the power handling capacity of a whip antenna
B. To reduce radiation resistance
C. To electrically lengthen a physically short antenna ✓
D. To lower the radiation angle
G4E02
What is the purpose of a corona ball on an HF mobile antenna?
A. To narrow the operating bandwidth of the antenna
B. To increase the “Q” of the antenna
C. To reduce the chance of damage if the antenna should strike an object
D. To reduce RF voltage discharge from the tip of the antenna while transmitting ✓
G4E03
Which of the following direct, fused power connections would be the best for a 100-watt HF mobile installation?
A. To the battery using heavy-gauge wire ✓
B. To the alternator or generator using heavy-gauge wire
C. To the battery using insulated heavy duty balanced transmission line
D. To the alternator or generator using insulated heavy duty balanced transmission line
G4E04
Why should DC power for a 100-watt HF transceiver not be supplied by a vehicle’s auxiliary power socket?
A. The socket is not wired with an RF-shielded power cable
B. The socket’s wiring may be inadequate for the current drawn by the transceiver ✓
C. The DC polarity of the socket is reversed from the polarity of modern HF transceivers
D. Drawing more than 50 watts from this socket could cause the engine to overheat
G4E05
Which of the following most limits an HF mobile installation?
A. “Picket fencing”
B. The wire gauge of the DC power line to the transceiver
C. Efficiency of the electrically short antenna ✓
D. FCC rules limiting mobile output power on the 75-meter band
G4E06
What is one disadvantage of using a shortened mobile antenna as opposed to a full-size antenna?
A. Short antennas are more likely to cause distortion of transmitted signals
B. Q of the antenna will be very low
C. Operating bandwidth may be very limited ✓
D. Harmonic radiation may increase
G4E07
Which of the following may cause receive interference to an HF transceiver installed in a vehicle?
A. The battery charging system
B. The fuel delivery system
C. The control computers
D. All these choices are correct ✓
G4E08
In what configuration are the individual cells in a solar panel connected together?
A. Series-parallel ✓
B. Shunt
C. Bypass
D. Full-wave bridge
G4E09
What is the approximate open-circuit voltage from a fully illuminated silicon photovoltaic cell?
A. 0.02 VDC
B. 0.5 VDC ✓
C. 0.2 VDC
D. 1.38 VDC
G4E10
Why should a series diode be connected between a solar panel and a storage battery that is being charged by the panel?
A. To prevent overload by regulating the charging voltage
B. To prevent discharge of the battery through the panel during times of low or no illumination ✓
C. To limit the current flowing from the panel to a safe value
D. To prevent damage to the battery due to excessive voltage at high illumination levels
G4E11
What precaution should be taken when connecting a solar panel to a lithium iron phosphate battery?
A. Ground the solar panel outer metal framework
B. Ensure the battery is placed terminals-up
C. A series resistor must be in place
D. The solar panel must have a charge controller ✓