General Class License Exam Questions

Subelement G4

Amateur Radio Practices

Groups

G4A - Station operation and setup
G4B - Test and monitoring equipment; two-tone test
G4C - Interference with consumer electronics; grounding; DSP
G4D - Speech processors; S meters; sideband operation near band edges
G4E - HF mobile radio installations; emergency and battery powered operation

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Group G4A Station operation and setup

G4A01 What is the purpose of the "notch filter" found on many HF transceivers?

To restrict the transmitter voice bandwidth
To reduce interference from carriers in the receiver passband
To eliminate receiver interference from impulse noise sources
To enhance the reception of a specific frequency on a crowded band

G4A02 What is one advantage of selecting the opposite or "reverse" sideband when receiving CW signals on a typical HF transceiver?

Interference from impulse noise will be eliminated
More stations can be accommodated within a given signal passband
It may be possible to reduce or eliminate interference from other signals
Accidental out of band operation can be prevented

G4A03 What is normally meant by operating a transceiver in "split" mode?

The radio is operating at half power
The transceiver is operating from an external power source
The transceiver is set to different transmit and receive frequencies
The transmitter is emitting an SSB signal, as opposed to DSB operation

G4A04 What reading on the plate current meter of a vacuum tube RF power amplifier indicates correct adjustment of the plate tuning control?

A pronounced peak
A pronounced dip
No change will be observed
A slow, rhythmic oscillation

G4A05 What is a reason to use Automatic Level Control (ALC) with an RF power amplifier?

To balance the transmitter audio frequency response
To reduce harmonic radiation
To reduce distortion due to excessive drive
To increase overall efficiency

G4A06 What type of device is often used to match transmitter output impedance to an impedance not equal to 50 ohms?

Balanced modulator
SWR Bridge
Antenna coupler or antenna tuner
Q Multiplier

G4A07 What condition can lead to permanent damage to a solid-state RF power amplifier?

Insufficient drive power
Low input SWR
Shorting the input signal to ground
Excessive drive power

G4A08 What is the correct adjustment for the load or coupling control of a vacuum tube RF power amplifier?

Minimum SWR on the antenna
Minimum plate current without exceeding maximum allowable grid current
Highest plate voltage while minimizing grid current
Maximum power output without exceeding maximum allowable plate current

G4A09 Why is a time delay sometimes included in a transmitter keying circuit?

To prevent stations from interfering with one another
To allow the transmitter power regulators to charge properly
To allow time for transmit-receive changeover operations to complete properly before RF output is allowed
To allow time for a warning signal to be sent to other stations

G4A10 What is the purpose of an electronic keyer?

Automatic transmit/receive switching
Automatic generation of strings of dots and dashes for CW operation
VOX operation
Computer interface for PSK and RTTY operation

G4A11 Which of the following is a use for the IF shift control on a receiver?

To avoid interference from stations very close to the receive frequency
To change frequency rapidly
To permit listening on a different frequency from that on which you are transmitting
To tune in stations that are slightly off frequency without changing your transmit frequency

G4A12 Which of the following is a common use for the dual VFO feature on a transceiver?

To allow transmitting on two frequencies at once
To permit full duplex operation, that is transmitting and receiving at the same time
To permit monitoring of two different frequencies
To facilitate computer interface

G4A13 What is one reason to use the attenuator function that is present on many HF transceivers?

To reduce signal overload due to strong incoming signals
To reduce the transmitter power when driving a linear amplifier
To reduce power consumption when operating from batteries
To slow down received CW signals for better copy

G4A14 What is likely to happen if a transceiver's ALC system is not set properly when transmitting AFSK signals with the radio using single sideband mode?

ALC will invert the modulation of the AFSK mode
Improper action of ALC distorts the signal and can cause spurious emissions
When using digital modes, too much ALC activity can cause the transmitter to overheat
All of these choices are correct

G4A15 Which of the following can be a symptom of transmitted RF being picked up by an audio cable carrying AFSK data signals between a computer and a transceiver?

The VOX circuit does not un-key the transmitter
The transmitter signal is distorted
Frequent connection timeouts
All of these choices are correct

Group G4B Test and monitoring equipment; two-tone test

G4B01 What item of test equipment contains horizontal and vertical channel amplifiers?

An ohmmeter
A signal generator
An ammeter
An oscilloscope

G4B02 Which of the following is an advantage of an oscilloscope versus a digital voltmeter?

An oscilloscope uses less power
Complex impedances can be easily measured
Input impedance is much lower
Complex waveforms can be measured

G4B03 Which of the following is the best instrument to use when checking the keying waveform of a CW transmitter?

An oscilloscope
A field strength meter
A sidetone monitor
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?

The local oscillator of the transmitter
An external RF oscillator
The transmitter balanced mixer output
The attenuated RF output of the transmitter

G4B05 Why is high input impedance desirable for a voltmeter?

It improves the frequency response
It decreases battery consumption in the meter
It improves the resolution of the readings
It decreases the loading on circuits being measured

G4B06 What is an advantage of a digital voltmeter as compared to an analog voltmeter?

Better for measuring computer circuits
Better for RF measurements
Better precision for most uses
Faster response

G4B07 What signals are used to conduct a two-tone test?

Two audio signals of the same frequency shifted 90 degrees
Two non-harmonically related audio signals
Two swept frequency tones
Two audio frequency range square wave signals of equal amplitude

G4B08 Which of the following instruments may be used to monitor relative RF output when making antenna and transmitter adjustments?

A field strength meter
An antenna noise bridge
A multimeter
A Q meter

G4B09 Which of the following can be determined with a field strength meter?

The radiation resistance of an antenna
The radiation pattern of an antenna
The presence and amount of phase distortion of a transmitter
The presence and amount of amplitude distortion of a transmitter

G4B10 Which of the following can be determined with a directional wattmeter?

Standing wave ratio
Antenna front-to-back ratio
RF interference
Radio wave propagation

G4B11 Which of the following must be connected to an antenna analyzer when it is being used for SWR measurements?

Receiver
Transmitter
Antenna and feed line
All of these choices are correct

G4B12 What problem can occur when making measurements on an antenna system with an antenna analyzer?

Permanent damage to the analyzer may occur if it is operated into a high SWR
Strong signals from nearby transmitters can affect the accuracy of measurements
The analyzer can be damaged if measurements outside the ham bands are attempted
Connecting the analyzer to an antenna can cause it to absorb harmonics

G4B13 What is a use for an antenna analyzer other than measuring the SWR of an antenna system?

Measuring the front to back ratio of an antenna
Measuring the turns ratio of a power transformer
Determining the impedance of an unknown or unmarked coaxial cable
Determining the gain of a directional antenna

G4B14 What is an instance in which the use of an instrument with analog readout may be preferred over an instrument with a digital readout?

When testing logic circuits
When high precision is desired
When measuring the frequency of an oscillator
When adjusting tuned circuits

G4B15 What type of transmitter performance does a two-tone test analyze?

Linearity
Percentage of suppression of carrier and undesired sideband for SSB
Percentage of frequency modulation
Percentage of carrier phase shift

Group G4C Interference with consumer electronics; grounding; DSP

G4C01 Which of the following might be useful in reducing RF interference to audio frequency devices?

Bypass inductor
Bypass capacitor
Forward-biased diode
Reverse-biased diode

G4C02 Which of the following could be a cause of interference covering a wide range of frequencies?

Not using a balun or line isolator to feed balanced antennas
Lack of rectification of the transmitter's signal in power conductors
Arcing at a poor electrical connection
Using a balun to feed an unbalanced antenna

G4C03 What sound is heard from an audio device or telephone if there is interference from a nearby single sideband phone transmitter?

A steady hum whenever the transmitter is on the air
On-and-off humming or clicking
Distorted speech
Clearly audible speech

G4C04 What is the effect on an audio device or telephone system if there is interference from a nearby CW transmitter?

On-and-off humming or clicking
A CW signal at a nearly pure audio frequency
A chirpy CW signal
Severely distorted audio

G4C05 What might be the problem if you receive an RF burn when touching your equipment while transmitting on an HF band, assuming the equipment is connected to a ground rod?

Flat braid rather than round wire has been used for the ground wire
Insulated wire has been used for the ground wire
The ground rod is resonant
The ground wire has high impedance on that frequency

G4C06 What effect can be caused by a resonant ground connection?

Overheating of ground straps
Corrosion of the ground rod
High RF voltages on the enclosures of station equipment
A ground loop

G4C07 What is one good way to avoid unwanted effects of stray RF energy in an amateur station?

Connect all equipment grounds together
Install an RF filter in series with the ground wire
Use a ground loop for best conductivity
Install a few ferrite beads on the ground wire where it connects to your station

G4C08 Which of the following would reduce RF interference caused by common-mode current on an audio cable?

Placing a ferrite choke around the cable
Adding series capacitors to the conductors
Adding shunt inductors to the conductors
Adding an additional insulating jacket to the cable

G4C09 How can a ground loop be avoided?

Connect all ground conductors in series
Connect the AC neutral conductor to the ground wire
Avoid using lock washers and star washers when making ground connections
Connect all ground conductors to a single point

G4C10 What could be a symptom of a ground loop somewhere in your station?

You receive reports of "hum" on your station's transmitted signal
The SWR reading for one or more antennas is suddenly very high
An item of station equipment starts to draw excessive amounts of current
You receive reports of harmonic interference from your station

G4C11 Which of the following is a function of a digital signal processor?

To provide adequate grounding
To remove noise from received signals
To increase antenna gain
To increase antenna bandwidth

G4C12 Which of the following is an advantage of a receiver DSP IF filter as compared to an analog filter?

A wide range of filter bandwidths and shapes can be created
Fewer digital components are required
Mixing products are greatly reduced
The DSP filter is much more effective at VHF frequencies

G4C13 Which of the following can perform automatic notching of interfering carriers?

Bandpass tuning
A Digital Signal Processor (DSP) filter
Balanced mixing
A noise limiter

Group G4D Speech processors; S meters; sideband operation near band edges

G4D01 What is the purpose of a speech processor as used in a modern transceiver?

Increase the intelligibility of transmitted phone signals during poor conditions
Increase transmitter bass response for more natural sounding SSB signals
Prevent distortion of voice signals
Decrease high-frequency voice output to prevent out of band operation

G4D02 Which of the following describes how a speech processor affects a transmitted single sideband phone signal?

It increases peak power
It increases average power
It reduces harmonic distortion
It reduces intermodulation distortion

G4D03 Which of the following can be the result of an incorrectly adjusted speech processor?

Distorted speech
Splatter
Excessive background pickup
All of these choices are correct

G4D04 What does an S meter measure?

Conductance
Impedance
Received signal strength
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?

It is 10 times less powerful
It is 20 times less powerful
It is 20 times more powerful
It is 100 times more powerful

G4D06 Where is an S meter found?

In a receiver
In an SWR bridge
In a transmitter
In a conductance bridge

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?

Approximately 1.5 times
Approximately 2 times
Approximately 4 times
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?

7.178 to 7.181 MHz
7.178 to 7.184 MHz
7.175 to 7.178 MHz
7.1765 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?

14.347 to 14.647 MHz
14.347 to 14.350 MHz
14.344 to 14.347 MHz
14.3455 to 14.3485 MHz

G4D10 How close to the lower edge of the 40-meter General Class phone segment should your displayed carrier frequency be when using 3 kHz wide LSB?

At least 3 kHz above the edge of the segment
At least 3 kHz below the edge of the segment
Your displayed carrier frequency may be set at the edge of the segment
At least 1 kHz above the edge of the segment

G4D11 How close to the upper edge of the 20-meter General Class band should your displayed carrier frequency be when using 3 kHz wide USB?

At least 3 kHz above the edge of the band
At least 3 kHz below the edge of the band
Your displayed carrier frequency may be set at the edge of the band
At least 1 kHz below the edge of the segment

Group G4E HF mobile radio installations; emergency and battery powered operation

G4E01 What is the purpose of a capacitance hat on a mobile antenna?

To increase the power handling capacity of a whip antenna
To allow automatic band changing
To electrically lengthen a physically short antenna
To allow remote tuning

G4E02 What is the purpose of a corona ball on a HF mobile antenna?

To narrow the operating bandwidth of the antenna
To increase the "Q" of the antenna
To reduce the chance of damage if the antenna should strike an object
To reduce high voltage discharge from the tip of the antenna

G4E03 Which of the following direct, fused power connections would be the best for a 100 watt HF mobile installation?

To the battery using heavy gauge wire
To the alternator or generator using heavy gauge wire
To the battery using resistor wire
To the alternator or generator using resistor wire

G4E04 Why is it best NOT to draw the DC power for a 100 watt HF transceiver from a vehicle's auxiliary power socket?

The socket is not wired with an RF-shielded power cable
The socket's wiring may be inadequate for the current drawn by the transceiver
The DC polarity of the socket is reversed from the polarity of modern HF transceivers
Drawing more than 50 watts from this socket could cause the engine to overheat

G4E05 Which of the following most limits the effectiveness of an HF mobile transceiver operating in the 75-meter band?

"Picket Fencing" signal variation
The wire gauge of the DC power line to the transceiver
The antenna system
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?

Short antennas are more likely to cause distortion of transmitted signals
Short antennas can only receive circularly polarized signals
Operating bandwidth may be very limited
Harmonic radiation may increase

G4E07 Which of the following may cause interference to be heard in the receiver of an HF radio installed in a recent model vehicle?

The battery charging system
The fuel delivery system
The vehicle control computer
All of these choices are correct

G4E08 What is the name of the process by which sunlight is changed directly into electricity?

Photovoltaic conversion
Photon emission
Photosynthesis
Photon decomposition

G4E09 What is the approximate open-circuit voltage from a fully illuminated silicon photovoltaic cell?

0.02 VDC
0.5 VDC
0.2 VDC
1.38 VDC

G4E10 What is the reason that a series diode is connected between a solar panel and a storage battery that is being charged by the panel?

The diode serves to regulate the charging voltage to prevent overcharge
The diode prevents self-discharge of the battery though the panel during times of low or no illumination
The diode limits the current flowing from the panel to a safe value
The diode greatly increases the efficiency during times of high illumination

G4E11 Which of the following is a disadvantage of using wind as the primary source of power for an emergency station?

The conversion efficiency from mechanical energy to electrical energy is less than 2 percent
The voltage and current ratings of such systems are not compatible with amateur equipment
A large energy storage system is needed to supply power when the wind is not blowing
All of these choices are correct