G4 - AMATEUR RADIO PRACTICES [5 Questions - 5 groups]
G4A - Two-tone Test; amplifier tuning and neutralization; DSP
G4A01 (B)
Which of the following is one use for a DSP in an amateur station?
A. To provide adequate grounding
B. To remove noise from received signals
C. To increase antenna gain
D. To increase antenna bandwidth
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G4A02 (B)
Which of the following instruments may be used to measure the output of a
single-sideband transmitter when performing a two-tone test of amplitude
linearity?
A. An audio distortion analyzer
B. An oscilloscope
C. A directional wattmeter
D. A high impedance audio voltmeter
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G4A03 (D)
Which of the following is needed for a DSP IF filter?
A. An Analog to Digital Converter
B. Digital to Analog Converter
C. A Digital Processor Chip
D. All of the these answers are correct
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G4A04 (A)
Which of the following is an advantage of a
receiver IF filter created with a
DSP as compared to an analog filter?
A. A wide range of filter bandwidths and shapes can be created
B. Fewer digital components are required
C. Mixing products are greatly reduced
D. The DSP filter is much more effective at VHF frequencies
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G4A05 (B)
How is DSP filtering accomplished?
A. By using direct signal phasing
B. By converting the signal from analog to digital and using digital processing
C. By up-converting the signal to VHF
D. By converting the signal from digital to analog and taking the difference of
mixing products
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G4A06 (B)
What reading on the plate current meter of a vacuum tube RF power amplifier
indicates correct adjustment of the plate tuning control?
A. A pronounced peak
B. A pronounced dip
C. No change will be observed
D. A slow, rhythmic oscillation
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G4A07 (D)
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. Maximum power output without exceeding maximum allowable plate current
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G4A08 (C)
Which of the following techniques is used to neutralize an RF amplifier?
A. Feed-forward compensation
B. Feed-forward cancellation
C. Negative feedback
D. Positive feedback
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G4A09 (B)
What does a neutralizing circuit do in an RF amplifier?
A. It controls differential gain
B. It cancels the effects of positive feedback
C. It eliminates AC hum from the power supply
D. It reduces incidental grid modulation
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G4A10 (B)
What is the reason for neutralizing the final amplifier stage of a
transmitter?
A. To limit the modulation index
B. To eliminate self oscillations
C. To cut off the final amplifier during standby periods
D. To keep the carrier on frequency
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G4A11 (A)
What type of transmitter performance does a two-tone test analyze?
A. Linearity
B. Carrier and undesired sideband suppression
C. Percentage of frequency modulation
D. Percentage of carrier phase shift
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G4A12 (B)
What type of 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
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G4A13 (B)
Which of the following performs automatic notching of interfering carriers?
A. Band pass tuning
B. A DSP filter
C. Balanced mixing
D. A noise limiter
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G4B - Test and monitoring equipment
G4B01 (D)
What item of test equipment contains horizontal and vertical channel
amplifiers?
A. An ohmmeter
B. A signal generator
C. An ammeter
D. An oscilloscope
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G4B02 (D)
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. Input impedance is much lower
D. Complex waveforms can be measured
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G4B03 (D)
How would a signal tracer normally be used?
A. To identify the source of radio transmissions
B. To make exact drawings of signal waveforms
C. To show standing wave patterns on open-wire feed-lines
D. To identify an inoperative stage in a receiver
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G4B04 (C)
How is a noise bridge normally used?
A. It is connected at an antenna's feed point and reads the antenna's noise figure
B. It is connected between a transmitter and an antenna and tuned for minimum SWR
C. It is connected between a receiver and an antenna of unknown impedance and is
adjusted for minimum noise
D. It is connected between an antenna and ground and tuned for minimum SWR
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G4B05 (A)
Which of the following is the best instrument to use to check the keying
waveform
of a CW transmitter?
A. A monitoring oscilloscope
B. A field-strength meter
C. A sidetone monitor
D. A wavemeter
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G4B06 (D)
What signal source is connected to the vertical input of a monitoring
oscilloscope when checking the quality of a transmitted signal?
A. The local oscillator of the transmitter
B. The audio input of the transmitter
C. The transmitter balanced mixer output
D. The attenuated RF output of the transmitter
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G4B07 (C)
What is an advantage of a digital voltmeter as compared to an analog voltmeter?
A. Better for measuring computer circuits
B. Better for RF measurements
C. Significantly better precision for most uses
D. Faster response
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G4B08 (A)
What instrument may be used to monitor relative RF output when making
antenna and transmitter adjustments?
A. A field-strength meter
B. An antenna noise bridge
C. A multimeter
D. A Q meter
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G4B09 (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?
A. Approximately 2 times
B. Approximately 3 times
C. Approximately 4 times
D. Approximately 5 times
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G4B10 (B)
Which of the following can be determined with a field strength meter?
A. The radiation resistance of an antenna
B. The radiation pattern of an antenna
C. The presence and amount of phase distortion of a transmitter
D. The presence and amount of amplitude distortion of a transmitter
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G4B11 (A)
Which of the following might be a use for a field strength meter?
A. Close-in radio direction-finding
B. A modulation monitor for a frequency or phase modulation transmitter
C. An overmodulation indicator for a SSB transmitter
D. A keying indicator for a RTTY or packet transmitter
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G4B12 (B)
What is one way a noise bridge might be used?
A. Determining an antenna's gain in dBi
B. Pre-tuning an antenna tuner
C. Pre-tuning a linear amplifier
D. Determining the line loss of the antenna system
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G4B13 (A)
What is one measurement that can be made with a dip meter?
A. The resonant frequency of a circuit
B. The tilt of the ionosphere
C. The gain of an antenna
D. The notch depth of a filter
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G4B14 (C)
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 feedline
D. All of these answers are correct
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G4B15 (A)
Which of the following can be measured with a directional wattmeter?
A. Standing Wave Ratio
B. Antenna front-to-back ratio
C. RF interference
D. Radio wave propagation
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G4B16 (D)
Why is high input impedance desirable for a voltmeter?
A. It improves the frequency response
B. It decreases battery consumption in the meter
C. It improves the resolution of the readings
D. It decreases the loading on circuits being measured
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G4C - Interference with consumer electronics; grounding
G4C01 (B)
Which of the following might be useful in reducing RF interference to
audio-frequency devices?
A. Bypass inductor
B. Bypass capacitor
C. Forward-biased diode
D. Reverse-biased diode
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G4C02 (B)
Which of the following should be installed if a properly operating amateur
station is interfering with a nearby telephone?
A. An RFI filter on the transmitter
B. An RFI filter at the affected telephone
C. A high pass filter on the transmitter
D. A high pass filter at the affected telephone
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G4C03 (C)
What sound is heard from a public-address system if there is interference
from a
nearby 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
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G4C04 (A)
What is the effect on a public-address system if there is interference
from
nearby 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
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G4C05 (D)
What might be the problem if you receive an RF burn when touching your
equipment
while transmitting on a HF band, assuming the equipment is connected to a ground
rod?
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 is resonant
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G4C06 (D)
Which of the following is an important reason to have a good station ground?
A. To reduce the likelihood of RF burns
B. To reduce the likelihood of electrical shock
C. To reduce interference
D. All of these answers are correct
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G4C07 (A)
What is one good way to avoid stray RF energy in an amateur station?
A. Keep the station's ground wire as short as possible
B. Install an RF filter in series with the ground wire
C. Use a ground loop for best conductivity
D. Install a few ferrite beads on the ground wire where it connects to your station
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G4C08 (A)
Which of the following is a reason to place ferrite beads around audio
cables to
reduce common mode RF interference?
A. They act as a series inductor
B. They act as a shunt capacitor
C. They lower the impedance of the cable
D. They increase the admittance of the cable
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G4C09 (C)
Which of the following statements about station grounding is true?
A. The chassis of each piece of station equipment should be tied together with
high-impedance conductors
B. If the chassis of all station equipment is connected with a good conductor, there
is no need to tie them to an earth ground
C. RF hot spots can occur in a station located above the ground floor if the
equipment is grounded by a long ground wire
D. A ground loop is an effective way to ground station equipment
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G4C10 (C)
Which of the following is covered in the National Electrical Code?
A. Acceptable bandwidth limits
B. Acceptable modulation limits
C. Electrical safety inside the ham shack
D. RF exposure limits of the human body
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G4C11 (A)
Which of the following can cause unintended rectification of RF signal energy
and can result in interference to your station as well as nearby radio and TV
receivers?
A. Induced currents in conductors that are in poor electrical contact
B. Induced voltages in conductors that are in good electrical contact
C. Capacitive coupling of the RF signal to ground
D. Excessive standing wave ratio (SWR) of the transmission line system
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G4C12 (C)
What is one cause of broadband radio frequency interference at an amateur radio station?
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. The use of horizontal, rather than vertical antennas
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G4C13 (D)
How can a ground loop be avoided?
A. Series connect all ground conductors
B. Connect the AC neutral conductor to the ground wire
C. Avoid using lock washers and star washers in making ground connections
D. Connect all ground conductors to a single point
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G4D - Speech processors; S meters; common connectors
G4D01 (D)
What is the reason for using a properly adjusted speech processor with a
single
sideband phone transmitter?
A. It reduces average transmitter power requirements
B. It reduces unwanted noise pickup from the microphone
C. It improves voice-frequency fidelity
D. It improves signal intelligibility at the receiver
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G4D02 (B)
Which of the following describes how a speech processor affects a
transmitted
single sideband signal?
A. It increases the peak power
B. It increases the average power
C. It reduces harmonic distortion
D. It reduces intermodulation distortion
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G4D03 (D)
Which of the following can be the result of an incorrectly adjusted speech processor?
A. Distorted speech
B. Splatter
C. Excessive background pickup
D. All of these answers are correct
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G4D04 (C)
What does an S-meter measure?
A. Conductance
B. Impedance
C. Received signal strength
D. Transmitter power output
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G4D05 (D)
How does an S-meter reading of 20 db over S-9 compare to an S-9 signal,
assuming
a properly calibrated S meter?
A. It is 10 times weaker
B. It is 20 times weaker
C. It is 20 times stronger
D. It is 100 times stronger
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G4D06 (A)
Where is an S-meter generally found?
A. In a receiver
B. In a SWR bridge
C. In a transmitter
D. In a conductance bridge
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G4D07 (A)
Which of the following describes a Type-N connector?
A. A moisture resistant RF connector useful to 10 GHz
B. A small bayonet connector used for data circuits
C. A threaded connector used for hydraulic systems
D. An audio connector used in surround sound installations
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G4D08 (D)
Which of the following connectors would be a good choice for a serial data port?
A. PL-259
B. Type N
C. Type SMA
D. DB-9
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G4D09 (C)
Which of these connector types is commonly used for RF service at
frequencies up
to 150 MHz?
A. Octal
B. RJ-11
C. UHF
D. DB-25
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G4D10 (C)
Which of these connector types is commonly used for audio signals in
amateur
radio stations?
A. PL-259
B. BNC
C. RCA Phono
D. Type N
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G4D11 (B)
What is the main reason to use keyed connectors over non-keyed types?
A. Prevention of use by unauthorized persons
B. Reduced chance of damage due to incorrect mating
C. Higher current carrying capacity
D. All of these choices are correct
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G4E - HF mobile radio installations; emergency and battery powered operation
G4E01 (D)
Which of the following emission types are permissible while operating HF mobile?
A. CW
B. SSB
C. FM
D. All of these choices are correct
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G4E02 (C)
What is alternator whine?
A. A DC emission from the alternator
B. A constant pitched tone or buzz in transmitted or received audio that occurs
whenever the ignition key is in the on position
C. A tone or buzz in transmitted or received audio that varies with engine speed
D. A mechanical sound from the alternator indicating current overload
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G4E03 (A)
Which of the following power connections would be the best for a 100-watt
HF
mobile installation?
A. A direct, fused connection to the battery using heavy gauge wire
B. A direct, fused connection to the alternator or generator using heavy gauge wire
C. A direct, fused connection to the battery using resistor wire
D. A direct, fused connection to the alternator or generator using resistor wire
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G4E04 (B)
Why is it best NOT to draw the DC power for a 100-watt HF transceiver from an
automobile's cigarette lighter socket?
A. The socket is not wired with an RF-shielded power cable
B. The socket's wiring may be inadequate for the current being drawn by the
transceiver
C. The DC polarity of the socket is reversed from the polarity of modern HF
transceivers
D. The power from the socket is never adequately filtered for HF transceiver
operation
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G4E05 (C)
Which of the following most limits the effectiveness of an HF mobile
transceiver operating in the 75 meter band?
A. “Picket Fencing” signal variation
B. The wire gauge of the DC power line to the transceiver
C. The HF mobile antenna system
D. FCC rules limiting mobile output power on the 75 meter band
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G4E06 (A)
Which of the following is true of an emergency generator installation?
A. The generator should be located in a well ventilated area
B. The generator should be insulated from ground
C. Fuel should be stored near the generator for rapid refueling in case of an
emergency
D. All of these choices are correct
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G4E07 (C)
When might a lead-acid storage battery give off explosive hydrogen gas?
A. When stored for long periods of time
B. When being discharged
C. When being charged
D. When not placed on a level surface
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G4E08 (A)
What is the name of the process by which sunlight is changed directly into electricity?
A. Photovoltaic conversion
B. Photon emission
C. Photosynthesis
D. Photon decomposition
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G4E09 (B)
What is the approximate open-circuit voltage from a modern, well illuminated
photovoltaic cell?
A. 0.02 VDC
B. 0.5 VDC
C. 0.2 VDC
D. 1.38 VDC
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G4E10 (A)
Which of these materials is used as the active element of a solar cell?
A. Doped Silicon
B. Nickel Hydride
C. Doped Platinum
D. Aluminum nitride
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G4E11 (C)
Which of the following is a disadvantage to using wind power as the primary
source of power for an emergency station?
A. The conversion efficiency from mechanical energy to electrical energy is less that
2 percent
B. The voltage and current ratings of such systems are not compatible with amateur
equipment
C. A large energy storage system is needed to supply power when the wind is not
blowing
D. All of these choices are correct
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G4E12 (A)
Which of the following is a primary reason for not placing a gasoline-fueled
generator inside an occupied area?
A. Danger of carbon monoxide poisoning
B. Danger of engine over torque
C. Lack of oxygen for adequate combustion
D. Lack of nitrogen for adequate combustion
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G4E13 (A)
Why would it be unwise to power your station by back feeding the output of a
gasoline generator into your house wiring by connecting the generator through an
AC wall outlet?
A. It might present a hazard for electric company workers
B. It is prone to RF interference
C. It may disconnect your RF ground
D. None of the above; this is an excellent expedient
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