HAM Toolkit/HAM Toolkit.iso/text/arrl/gen_2.new

Text File | 1994-02-09 | 46KB | 1,457 lines

G4B  Test equipment: oscilloscope; signal tracer; antenna noise
bridge; monitoring oscilloscope; field-strength meters

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

G4B02 (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

G4B03 (B)
Why would you use an antenna noise bridge?
A.  To measure the noise figure of an antenna or other electrical
circuit
B.  To measure the impedance of an antenna or other electrical
circuit
C.  To cancel electrical noise picked up by an antenna
D.  To tune out noise in a receiver

G4B04 (C)
How is an antenna 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 is
tuned for minimum SWR
C.  It is connected between a receiver and an unknown impedance
and is tuned for minimum noise
D.  It is connected between an antenna and ground and is tuned
for minimum SWR

G4B05 (A)
What is the best instrument to use to check the signal quality of
a CW or single-sideband phone transmitter?
A.  A monitoring oscilloscope
B.  A field-strength meter
C.  A sidetone monitor
D.  A signal tracer and an audio amplifier

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 IF output of a monitoring receiver
B.  The audio input of the transmitter
C.  The RF signals of a nearby receiving antenna
D.  The RF output of the transmitter

G4B07 (A)
What instrument can be used to determine the horizontal radiation
pattern of an antenna?
A.  A field-strength meter
B.  A grid-dip meter
C.  An oscilloscope
D.  A signal tracer and an audio amplifier

G4B08 (C)
How is a field-strength meter normally used?
A.  To determine the standing-wave ratio on a transmission line
B.  To check the output modulation of a transmitter
C.  To monitor relative RF output
D.  To increase average transmitter output

G4B09 (A)
What simple instrument may be used to monitor relative RF output
during antenna and transmitter adjustments?
A.  A field-strength meter
B.  An antenna noise bridge
C.  A multimeter
D.  A metronome

G4B10 (B)
If the power output of a transmitter is increased by four times,
how might a nearby receiver's S-meter reading change?
A.  Decrease by approximately one S unit
B.  Increase by approximately one S unit
C.  Increase by approximately four S units
D.  Decrease by approximately four S units

G4B11 (C)
By how many times must the power output of a transmitter be
increased to raise the S-meter reading on a nearby receiver from
S8 to S9?
A.  Approximately 2 times
B.  Approximately 3 times
C.  Approximately 4 times
D.  Approximately 5 times

G4C  Audio rectification in consumer electronics, RF ground

G4C01 (B)
What devices would you install to reduce or eliminate
audio-frequency interference to home-entertainment systems?
A.  Bypass inductors
B.  Bypass capacitors
C.  Metal-oxide varistors
D.  Bypass resistors

G4C02 (B)
What should be done if a properly operating amateur station is
the cause of interference to a nearby telephone?
A.  Make internal adjustments to the telephone equipment
B.  Ask the telephone company to install RFI filters
C.  Stop transmitting whenever the telephone is in use
D.  Ground and shield the local telephone distribution amplifier

G4C03 (C)
What sound is heard from a public-address system if audio
rectification of a nearby single-sideband phone transmission
occurs?
A.  A steady hum whenever the transmitter's carrier is on the air
B.  On-and-off humming or clicking
C.  Distorted speech from the transmitter's signals
D.  Clearly audible speech from the transmitter's signals

G4C04 (A)
What sound is heard from a public-address system if audio
rectification of a nearby CW transmission occurs?
A.  On-and-off humming or clicking
B.  Audible, possibly distorted speech
C.  Muffled, severely distorted speech
D.  A steady whistling

G4C05 (C)
How can you minimize the possibility of audio rectification of
your transmitter's signals?
A.  By using a solid-state transmitter
B.  By using CW emission only
C.  By ensuring that all station equipment is properly grounded
D.  By installing bypass capacitors on all power supply
rectifiers

G4C06 (D)
If your third-floor amateur station has a ground wire running 33
feet down to a ground rod, why might you get an RF burn if you
touch the front panel of your HF transceiver?
A.  Because the ground rod is not making good contact with moist
earth
B.  Because the transceiver's heat-sensing circuit is not working
to start the cooling fan
C.  Because of a bad antenna connection, allowing the RF energy
to take an easier path out of the transceiver through you
D.  Because the ground wire is a resonant length on several HF
bands and acts more like an antenna than an RF ground connection

G4C07 (A)
What is NOT an important reason to have a good station ground?
A.  To reduce the cost of operating a station
B.  To reduce electrical noise
C.  To reduce interference
D.  To reduce the possibility of electric shock

G4C08 (A)
What is one good way to avoid stray RF energy in your amateur
station?
A.  Keep the station's ground wire as short as possible
B.  Use a beryllium ground wire for best conductivity
C.  Drive the ground rod at least 14 feet into the ground
D.  Make a couple of loops in the ground wire where it connects
to your station

G4C09 (B)
Which statement about station grounding is NOT true?
A.  Braid from RG-213 coaxial cable makes a good conductor to tie
station equipment together into a station ground
B.  Only transceivers and power amplifiers need to be tied into a
station ground
C.  According to the National Electrical Code, there should be
only one grounding system in a building
D.  The minimum length for a good ground rod is 8 feet

G4C10 (C)
Which statement 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

G4C11 (D)
Which of the following is NOT covered in the National Electrical
Code?
A.  Minimum conductor sizes for different lengths of amateur
antennas
B.  The size and composition of grounding conductors
C.  Electrical safety inside the ham shack
D.  The RF exposure limits of the human body

G4D  Speech processors; PEP calculations; wire sizes and fuses

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

G4D02 (B)
If a single-sideband phone transmitter is 100% modulated, what
will a speech processor do to the transmitter's power?
A.  It will increase the output PEP
B.  It will add nothing to the output PEP
C.  It will decrease the peak power output
D.  It will decrease the average power output

G4D03 (B)
How is the output PEP of a transmitter calculated if an
oscilloscope is used to measure the transmitter's peak load
voltage across a resistive load?
A.  PEP = [(Vp)(Vp)] / (RL)
B.  PEP = [(0.707 PEV)(0.707 PEV)] / RL
C.  PEP = (Vp)(Vp)(RL)
D.  PEP = [(1.414 PEV)(1.414 PEV)] / RL

G4D04 (A)
What is the output PEP from a transmitter if an oscilloscope
measures 200 volts peak-to-peak across a 50-ohm resistor
connected to the transmitter output?
A.  100 watts
B.  200 watts
C.  400 watts
D.  1000 watts

G4D05 (B)
What is the output PEP from a transmitter if an oscilloscope
measures 500 volts peak-to-peak across a 50-ohm resistor
connected to the transmitter output?
A.  500 watts
B.  625 watts
C.  1250 watts
D.  2500 watts

G4D06 (B)
What is the output PEP of an unmodulated carrier transmitter if
an average-reading wattmeter connected to the transmitter output
indicates 1060 watts?
A.  530 watts
B.  1060 watts
C.  1500 watts
D.  2120 watts

G4D07 (A)
Which wires in a four-conductor line cord should be attached to
fuses in a 240-VAC primary (single phase) power supply?
A.  Only the "hot" (black and red) wires
B.  Only the "neutral" (white) wire
C.  Only the ground (bare) wire
D.  All wires

G4D08 (A)
What size wire is normally used on a 15-ampere, 120-VAC household
lighting circuit?
A.  AWG number 14
B.  AWG number 16
C.  AWG number 18
D.  AWG number 22

G4D09 (D)
What size wire is normally used on a 20-ampere, 120-VAC household
appliance circuit?
A.  AWG number 20
B.  AWG number 16
C.  AWG number 14
D.  AWG number 12

G4D10 (D)
What maximum size fuse or circuit breaker should be used in a
household appliance circuit using AWG number 12 wiring?
A.  100 amperes
B.  60 amperes
C.  30 amperes
D.  20 amperes

G4D11 (A)
What maximum size fuse or circuit breaker should be used in a
household appliance circuit using AWG number 14 wiring?
A.  15 amperes
B.  20 amperes
C.  30 amperes
D.  60 amperes

G4E  RF safety

G4E01 (A)
Depending on the wavelength of the signal, the energy density of
the RF field, and other factors, in what way can RF energy affect
body tissue?
A.  It heats the tissue
B.  It causes radiation poisoning
C.  It causes blood flow to stop
D.  It produces genetic changes in the tissue

G4E02 (C)
If you operate your amateur station with indoor antennas, what
precautions should you take when you install them?
A.  Locate the antennas close to your operating position to
minimize feed-line length
B.  Position the antennas along the edge of a wall where it meets
the floor or ceiling to reduce parasitic radiation
C.  Locate the antennas as far away as possible from living
spaces that will be occupied while you are operating
D.  Position the antennas parallel to electrical power wires to
take advantage of parasitic effects

G4E03 (A)
What precaution should you take whenever you make adjustments to
the feed system of a parabolic dish antenna?
A.  Be sure no one can activate the transmitter
B.  Disconnect the antenna-positioning mechanism
C.  Point the dish away from the sun so it doesn't concentrate
solar energy on you
D.  Be sure you and the antenna structure are properly grounded

G4E04 (B)
What is one important thing to consider when using an indoor
antenna?
A.  Use stranded wire to reduce stray RF
B.  Ensure that the antenna is as far away from people as
possible
C.  Use only a Yagi antenna to direct the signals away from
people
D.  Use as much power as possible to ensure that your signal gets
out

G4E05 (A)
Why should a protective fence be placed around the base of a
ground-mounted parabolic dish transmitting antenna?
A.  To reduce the possibility of persons being harmed by RF
energy during transmissions
B.  To reduce the possibility that animals will damage the
antenna
C.  To increase the property value through increased security
awareness
D.  To protect the antenna from lightning damage and provide a
good ground system for the installation

G4E06 (B)
What RF-safety precautions should you take before beginning
repairs on an antenna?
A.  Be sure you and the antenna structure are grounded
B.  Be sure to turn off the transmitter and disconnect the feed
line
C.  Inform your neighbors so they are aware of your intentions
D.  Turn off the main power switch in your house

G4E07 (D)
What precaution should you take when installing a ground-mounted
antenna?
A.  It should not be installed higher than you can reach
B.  It should not be installed in a wet area
C.  It should be painted so people or animals do not accidentally
run into it
D.  It should be installed so no one can come in contact with it

G4E08 (B)
What precautions should you take before beginning repairs on a
microwave feed horn or waveguide?
A.  Be sure to wear tight-fitting clothes and gloves to protect
your body and hands from sharp edges
B.  Be sure the transmitter is turned off and the power source is
disconnected
C.  Be sure the weather is dry and sunny
D.  Be sure propagation conditions are unfavorable for
tropospheric ducting

G4E09 (D)
Why should directional high-gain antennas be mounted higher than
nearby structures?
A.  So they will be dried by the wind after a heavy rain storm
B.  So they will not damage nearby structures with RF energy
C.  So they will receive more sky waves and fewer ground waves
D.  So they will not direct RF energy toward people in nearby
structures

G4E10 (C)
For best RF safety, where should the ends and center of a dipole
antenna be located?
A.  Near or over moist ground so RF energy will be radiated away
from the ground
B.  As close to the transmitter as possible so RF energy will be
concentrated near the transmitter
C.  As high as possible to prevent people from coming in contact
with the antenna
D.  Close to the ground so simple adjustments can be easily made
without climbing a ladder

G4E11 (B)
Which property of RF energy is NOT important in estimating the
energy's effect on body tissue?
A.  The polarization
B.  The critical angle
C.  The power density
D.  The frequency

SUBELEMENT G5 - ELECTRICAL PRINCIPLES [2 exam questions - 2
groups]

G5A  Impedance, including matching; resistance, including ohm;
reactance, inductance, capacitance and metric divisions of these
values

G5A01 (C)
What is impedance?
A.  The electric charge stored by a capacitor
B.  The opposition to the flow of AC in a circuit containing only
capacitance
C.  The opposition to the flow of AC in a circuit
D.  The force of repulsion between one electric field and another
with the same charge

G5A02 (B)
What is reactance?
A.  Opposition to DC caused by resistors
B.  Opposition to AC caused by inductors and capacitors
C.  A property of ideal resistors in AC circuits
D.  A large spark produced at switch contacts when an inductor is
de-energized

G5A03 (D)
In an inductor, what causes opposition to the flow of AC?
A.  Resistance
B.  Reluctance
C.  Admittance
D.  Reactance

G5A04 (C)
In a capacitor, what causes opposition to the flow of AC?
A.  Resistance
B.  Reluctance
C.  Reactance
D.  Admittance

G5A05 (D)
How does a coil react to AC?
A.  As the frequency of the applied AC increases, the reactance
decreases
B.  As the amplitude of the applied AC increases, the reactance
increases
C.  As the amplitude of the applied AC increases, the reactance
decreases
D.  As the frequency of the applied AC increases, the reactance
increases

G5A06 (A)
How does a capacitor react to AC?
A.  As the frequency of the applied AC increases, the reactance
decreases
B.  As the frequency of the applied AC increases, the reactance
increases
C.  As the amplitude of the applied AC increases, the reactance
increases
D.  As the amplitude of the applied AC increases, the reactance
decreases

G5A07 (A)
When will a power source deliver maximum output to the load?
A.  When the impedance of the load is equal to the impedance of
the source
B.  When the load resistance is infinite
C.  When the power-supply fuse rating equals the primary winding
current
D.  When air wound transformers are used instead of iron-core
transformers

G5A08 (D)
What happens when the impedance of an electrical load is equal to
the internal impedance of the power source?
A.  The source delivers minimum power to the load
B.  The electrical load is shorted
C.  No current can flow through the circuit
D.  The source delivers maximum power to the load

G5A09 (A)
Why is impedance matching important?
A.  So the source can deliver maximum power to the load
B.  So the load will draw minimum power from the source
C.  To ensure that there is less resistance than reactance in the
circuit
D.  To ensure that the resistance and reactance in the circuit
are equal

G5A10 (B)
What unit is used to measure reactance?
A.  Mho
B.  Ohm
C.  Ampere
D.  Siemens

G5A11 (B)
What unit is used to measure impedance?
A.  Volt
B.  Ohm
C.  Ampere
D.  Watt

G5B  Decibel, Ohm's Law, current and voltage dividers, electrical
power calculations and series and parallel components,
transformers (either voltage or impedance), sine wave
root-mean-square (RMS) value

G5B01 (B)
A two-times increase in power results in a change of how many dB?
A.  1 dB higher
B.  3 dB higher
C.  6 dB higher
D.  12 dB higher

G5B02 (B)
How can you decrease your transmitter's power by 3 dB?
A.  Divide the original power by 1.5
B.  Divide the original power by 2
C.  Divide the original power by 3
D.  Divide the original power by 4

G5B03  (D)
How can you increase your transmitter's power by 6 dB?
A.  Multiply the original power by 1.5
B.  Multiply the original power by 2
C.  Multiply the original power by 3
D.  Multiply the original power by 4

G5B04 (C)
If a signal-strength report is "10 dB over S9", what should the
report be if the transmitter power is reduced from 1500 watts to
150 watts?
A.  S5
B.  S7
C.  S9
D.  S9 plus 5 dB

G5B05 (C)
If a signal-strength report is "20 dB over S9", what should the
report be if the transmitter power is reduced from 1500 watts to
15 watts?
A.  S5
B.  S7
C.  S9
D.  S9 plus 10 dB

G5B06 (D)
If a 1.0-ampere current source is connected to two
parallel-connected 10-ohm resistors, how much current passes
through each resistor?
A.  10 amperes
B.  2 amperes
C.  1 ampere
D.  0.5 ampere

G5B07 (B)
In a parallel circuit with a voltage source and several branch
resistors, how is the total current related to the current in the
branch resistors?
A.  It equals the average of the branch current through each
resistor
B.  It equals the sum of the branch current through each resistor
C.  It decreases as more parallel resistors are added to the
circuit
D.  It is the sum of each resistor's voltage drop multiplied by
the total number of resistors

G5B08 (B)
How many watts of electrical power are used if 400 VDC is
supplied to an 800-ohm load?
A.  0.5 watts
B.  200 watts
C.  400 watts
D.  320,000 watts

G5B09 (D)
How many watts of electrical power are used by a 12-VDC light
bulb that draws 0.2 amperes?
A.  60 watts
B.  24 watts
C.  6 watts
D.  2.4 watts

G5B10  (A)
How many watts are being dissipated when 7.0 milliamperes flow
through 1.25 kilohms?
A.  Approximately 61 milliwatts
B.  Approximately 39 milliwatts
C.  Approximately 11 milliwatts
D.  Approximately 9 milliwatts

G5B11 (C)
What is the voltage across a 500-turn secondary winding in a
transformer if the 2250-turn primary is connected to 120 VAC?
A.  2370 volts
B.  540 volts
C.  26.7 volts
D.  5.9 volts

G5B12 (A)
What is the turns ratio of a transformer to match an audio
amplifier having a 600-ohm output impedance to a speaker having a
4-ohm impedance?
A.  12.2 to 1
B.  24.4 to 1
C.  150 to 1
D.  300 to 1

G5B13 (D)
What is the impedance of a speaker that requires a transformer
with a turns ratio of 24 to 1 to match an audio amplifier having
an output impedance of 2000 ohms?
A.  576 ohms
B.  83.3 ohms
C.  7.0 ohms
D.  3.5 ohms

G5B14 (B)
A DC voltage equal to what value of an applied sine-wave AC
voltage would produce the same amount of heat over time in a
resistive element?
A.  The peak-to-peak value
B.  The RMS value
C.  The average value
D.  The peak value

G5B15 (D)
What is the peak-to-peak voltage of a sine wave that has an RMS
voltage of 120 volts?
A.  84.8 volts
B.  169.7 volts
C.  204.8 volts
D.  339.4 volts

G5B16 (B)
A sine wave of 17 volts peak is equivalent to how many volts RMS?
A.  8.5 volts
B.  12 volts
C.  24 volts
D.  34 volts

SUBELEMENT G6 - CIRCUIT COMPONENTS [1 exam question - 1 group]

G6A  Resistors, capacitors, inductors, rectifiers and
transistors, etc.

G6A01 (C)
If a carbon resistor's temperature is increased, what will happen
to the resistance?
A.  It will increase by 20% for every 10 degrees centigrade
B.  It will stay the same
C.  It will change depending on the resistor's temperature
coefficient rating
D.  It will become time dependent

G6A02 (D)
What type of capacitor is often used in power-supply circuits to
filter the rectified AC?
A.  Disc ceramic
B.  Vacuum variable
C.  Mica
D.  Electrolytic

G6A03 (D)
What type of capacitor is used in power-supply circuits to filter
transient voltage spikes across the transformer's secondary
winding?
A.  High-value
B.  Trimmer
C.  Vacuum variable
D.  Suppressor

G6A04 (B)
Where is the source of energy connected in a transformer?
A.  To the secondary winding
B.  To the primary winding
C.  To the core
D.  To the plates

G6A05 (A)
If no load is attached to the secondary winding of a transformer,
what is current in the primary winding called?
A.  Magnetizing current
B.  Direct current
C.  Excitation current
D.  Stabilizing current

G6A06 (C)
What is the peak-inverse-voltage rating of a power-supply
rectifier?
A.  The maximum transient voltage the rectifier will handle in
the conducting direction
B.  1.4 times the AC frequency
C.  The maximum voltage the rectifier will handle in the
non-conducting direction
D.  2.8 times the AC frequency

G6A07 (A)
What are the two major ratings that must not be exceeded for
silicon-diode rectifiers used in power-supply circuits?
A.  Peak inverse voltage; average forward current
B.  Average power; average voltage
C.  Capacitive reactance; avalanche voltage
D.  Peak load impedance; peak voltage

G6A08 (A)
Why should a resistor and capacitor be wired in parallel with
power-supply rectifier diodes?
A.  To equalize voltage drops and guard against transient voltage
spikes
B.  To ensure that the current through each diode is about the
same
C.  To smooth the output waveform
D.  To decrease the output voltage

G6A09 (A)
What is the output waveform of an unfiltered full-wave rectifier
connected to a resistive load?
A.  A series of pulses at twice the frequency of the AC input
B.  A series of pulses at the same frequency as the AC input
C.  A sine wave at half the frequency of the AC input
D.  A steady DC voltage

G6A10 (B)
A half-wave rectifier conducts during how many degrees of each
cycle?
A.  90 degrees
B.  180 degrees
C.  270 degrees
D.  360 degrees

G6A11 (D)
A full-wave rectifier conducts during how many degrees of each
cycle?
A.  90 degrees
B.  180 degrees
C.  270 degrees
D.  360 degrees

SUBELEMENT G7 - PRACTICAL CIRCUITS [1 exam question - 1 group]

G7A  Power supplies and filters; single-sideband transmitters and
receivers

G7A01 (B)
What safety feature does a power-supply bleeder resistor provide?
A.  It improves voltage regulation
B.  It discharges the filter capacitors
C.  It removes shock hazards from the induction coils
D.  It eliminates ground-loop current

G7A02 (A)
Where is a power-supply bleeder resistor connected?
A.  Across the filter capacitor
B.  Across the power-supply input
C.  Between the transformer primary and secondary windings
D.  Across the inductor in the output filter

G7A03 (D)
What components are used in a power-supply filter network?
A.  Diodes
B.  Transformers and transistors
C.  Quartz crystals
D.  Capacitors and inductors

G7A04 (D)
What should be the peak-inverse-voltage rating of the rectifier
in a full-wave power supply?
A.  One-quarter the normal output voltage of the power supply
B.  Half the normal output voltage of the power supply
C.  Equal to the normal output voltage of the power supply
D.  Double the normal peak output voltage of the power supply

G7A05 (D)
What should be the peak-inverse-voltage rating of the rectifier
in a half-wave power supply?
A.  One-quarter to one-half the normal peak output voltage of the
power supply
B.  Half the normal output voltage of the power supply
C.  Equal to the normal output voltage of the power supply
D.  One to two times the normal peak output voltage of the power
supply

G7A06 (B)
What should be the impedance of a low-pass filter as compared to
the impedance of the transmission line into which it is inserted?
A.  Substantially higher
B.  About the same
C.  Substantially lower
D.  Twice the transmission line impedance

G7A07 (B)
In a typical single-sideband phone transmitter, what circuit
processes signals from the balanced modulator and sends signals
to the mixer?
A.  Carrier oscillator
B.  Filter
C.  IF amplifier
D.  RF amplifier

G7A08 (D)
In a single-sideband phone transmitter, what circuit processes
signals from the carrier oscillator and the speech amplifier and
sends signals to the filter?
A.  Mixer
B.  Detector
C.  IF amplifier
D.  Balanced modulator

G7A09 (C)
In a single-sideband phone superheterodyne receiver, what circuit
processes signals from the RF amplifier and the local oscillator
and sends signals to the IF filter?
A.  Balanced modulator
B.  IF amplifier
C.  Mixer
D.  Detector

G7A10 (D)
In a single-sideband phone superheterodyne receiver, what circuit
processes signals from the IF amplifier and the BFO and sends
signals to the AF amplifier?
A.  RF oscillator
B.  IF filter
C.  Balanced modulator
D.  Detector

G7A11 (B)
In a single-sideband phone superheterodyne receiver, what circuit
processes signals from the IF filter and sends signals to the
detector?
A.  RF oscillator
B.  IF amplifier
C.  Mixer
D.  BFO

SUBELEMENT G8 - SIGNALS AND EMISSIONS [2 exam questions - 2
groups]

G8A  Signal information, AM, FM, single and double sideband and
carrier, bandwidth, modulation envelope, deviation,
overmodulation

G8A01 (D)
What type of modulation system changes the amplitude of an RF
wave for the purpose of conveying information?
A.  Frequency modulation
B.  Phase modulation
C.  Amplitude-rectification modulation
D.  Amplitude modulation

G8A02 (B)
What type of modulation system changes the phase of an RF wave
for the purpose of conveying information?
A.  Pulse modulation
B.  Phase modulation
C.  Phase-rectification modulation
D.  Amplitude modulation

G8A03 (D)
What type of modulation system changes the frequency of an RF
wave for the purpose of conveying information?
A.  Phase-rectification modulation
B.  Frequency-rectification modulation
C.  Amplitude modulation
D.  Frequency modulation

G8A04 (B)
What emission is produced by a reactance modulator connected to
an RF power amplifier?
A.  Multiplex modulation
B.  Phase modulation
C.  Amplitude modulation
D.  Pulse modulation

G8A05 (D)
what emission type does the instantaneous amplitude (envelope)
of the RF signal vary in accordance with the modulating audio?
A.  Frequency shift keying
B.  Pulse modulation
C.  Frequency modulation
D.  Amplitude modulation

G8A06 (C)
How much is the carrier suppressed below peak output power in a
single-sideband phone transmission?
A.  No more than 20 dB
B.  No more than 30 dB
C.  At least 40 dB
D.  At least 60 dB

G8A07 (C)
What is one advantage of carrier suppression in a double-sideband
phone transmission?
A.  Only half the bandwidth is required for the same information
content
B.  Greater modulation percentage is obtainable with lower
distortion
C.  More power can be put into the sidebands
D.  Simpler equipment can be used to receive a double-sideband
suppressed-carrier signal

G8A08 (A)
Which popular phone emission uses the narrowest frequency
bandwidth?
A.  Single-sideband
B.  Double-sideband
C.  Phase-modulated
D.  Frequency-modulated

G8A09 (D)
What happens to the signal of an overmodulated single-sideband or
double-sideband phone transmitter?
A.  It becomes louder with no other effects
B.  It occupies less bandwidth with poor high-frequency response
C.  It has higher fidelity and improved signal-to-noise ratio
D.  It becomes distorted and occupies more bandwidth

G8A10 (B)
How should the microphone gain control be adjusted on a
single-sideband phone transmitter?
A.  For full deflection of the ALC meter on modulation peaks
B.  For slight movement of the ALC meter on modulation peaks
C.  For 100% frequency deviation on modulation peaks
D.  For a dip in plate current

G8A11 (C)
What is meant by flattopping in a single-sideband phone
transmission?
A.  Signal distortion caused by insufficient collector current
B.  The transmitter's automatic level control is properly
adjusted
C.  Signal distortion caused by excessive drive
D.  The transmitter's carrier is properly suppressed

G8B  Frequency mixing, multiplication, bandwidths, HF data
communications

G8B01 (A)
What receiver stage combines a 14.25-MHz input signal with a
13.795-MHz oscillator signal to produce a 455-kHz intermediate
frequency (IF) signal?
A.  Mixer
B.  BFO
C.  VFO
D.  Multiplier

G8B02 (B)
If a receiver mixes a 13.800-MHz VFO with a 14.255-MHz received
signal to produce a 455-kHz intermediate frequency (IF) signal,
what type of interference will a 13.345-MHz signal produce in the
receiver?
A.  Local oscillator
B.  Image response
C.  Mixer interference
D.  Intermediate interference

G8B03 (A)
What stage in a transmitter would change a 5.3-MHz input signal
to 14.3 MHz?
A.  A mixer
B.  A beat frequency oscillator
C.  A frequency multiplier
D.  A linear translator

G8B04 (D)
What is the name of the stage in a VHF FM transmitter that
selects a harmonic of an HF signal to reach the desired operating
frequency?
A.  Mixer
B.  Reactance modulator
C.  Preemphasis network
D.  Multiplier

G8B05 (C)
Why isn't frequency modulated (FM) phone used below 29.5 MHz?
A.  The transmitter efficiency for this mode is low
B.  Harmonics could not be attenuated to practical levels
C.  The bandwidth would exceed FCC limits
D.  The frequency stability would not be adequate

G8B06 (D)
What is the total bandwidth of an FM-phone transmission having a
5-kHz deviation and a 3-kHz modulating frequency?
A.  3 kHz
B.  5 kHz
C.  8 kHz
D.  16 kHz

G8B07 (B)
What is the frequency deviation for a 12.21-MHz
reactance-modulated oscillator in a 5-kHz deviation, 146.52-MHz
FM-phone transmitter?
A.  41.67 Hz
B.  416.7 Hz
C.  5 kHz
D.  12 kHz

G8B08 (C)
How is frequency shift related to keying speed in an FSK signal?
A.  The frequency shift in hertz must be at least four times the
keying speed in WPM
B.  The frequency shift must not exceed 15 Hz per WPM of keying
speed
C.  Greater keying speeds require greater frequency shifts
D.  Greater keying speeds require smaller frequency shifts

G8B09 (B)
What do RTTY, Morse code, AMTOR and packet communications have in
common?
A.  They are multipath communications
B.  They are digital communications
C.  They are analog communications
D.  They are only for emergency communications

G8B10 (C)
What is the duty cycle required of a transmitter when sending
Mode B (FEC) AMTOR?
A.  50%
B.  75%
C.  100%
D.  125%

G8B11 (D)
In what segment of the 20-meter band are most AMTOR operations
found?
A.  At the bottom of the slow-scan TV segment, near 14.230 MHz
B.  At the top of the SSB phone segment, near 14.325 MHz
C.  In the middle of the CW segment, near 14.100 MHz
D.  At the bottom of the RTTY segment, near 14.075 MHz

SUBELEMENT G9 - ANTENNAS AND FEED LINES [4 exam questions - 4
groups]

G9A  Yagi antennas - physical dimensions, impedance matching
radiation patterns, directivity and major lobes

G9A01 (A)
How can the SWR bandwidth of a parasitic beam antenna be
increased?
A.  Use larger diameter elements
B.  Use closer element spacing
C.  Use traps on the elements
D.  Use tapered-diameter elements

G9A02 (B)
Approximately how long is the driven element of a Yagi antenna
for 14.0 MHz?
A.  17 feet
B.  33 feet
C.  35 feet
D.  66 feet

G9A03 (B)
Approximately how long is the director element of a Yagi antenna
for 21.1 MHz?
A.  42 feet
B.  21 feet
C.  17 feet
D.  10.5 feet

G9A04 (C)
Approximately how long is the reflector element of a Yagi antenna
for 28.1 MHz?
A.  8.75 feet
B.  16.6 feet
C.  17.5 feet
D.  35 feet

G9A05 (B)
Which statement about a three-element Yagi antenna is true?
A.  The reflector is normally the shortest parasitic element
B.  The director is normally the shortest parasitic element
C.  The driven element is the longest parasitic element
D.  Low feed-point impedance increases bandwidth

G9A06 (A)
What is one effect of increasing the boom length and adding
directors to a Yagi antenna?
A.  Gain increases
B.  SWR increases
C.  Weight decreases
D.  Windload decreases

G9A07 (D)
What are some advantages of a Yagi with wide element spacing?
A.  High gain, lower loss and a low SWR
B.  High front-to-back ratio and lower input resistance
C.  Shorter boom length, lower weight and wind resistance
D.  High gain, less critical tuning and wider bandwidth

G9A08 (C)
Why is a Yagi antenna often used for radio communications on the
20-meter band?
A.  It provides excellent omnidirectional coverage in the
horizontal plane
B.  It is smaller, less expensive and easier to erect than a
dipole or vertical antenna
C.  It helps reduce interference from other stations off to the
side or behind
D.  It provides the highest possible angle of radiation for the
HF bands

G9A09 (C)
What does "antenna front-to-back ratio" mean in reference to a
Yagi antenna?
A.  The number of directors versus the number of reflectors
B.  The relative position of the driven element with respect to
the reflectors and directors
C.  The power radiated in the major radiation lobe compared to
the power radiated in exactly the opposite direction
D.  The power radiated in the major radiation lobe compared to
the power radiated 90 degrees away from that direction

G9A10 (C)
What is the "main lobe" of a Yagi antenna radiation pattern?
A.  The direction of least radiation from the antenna
B.  The point of maximum current in a radiating antenna element
C.  The direction of maximum radiated field strength from the
antenna
D.  The maximum voltage standing wave point on a radiating
element

G9A11  (A)
What is a good way to get maximum performance from a Yagi
antenna?
A.  Optimize the lengths and spacing of the elements
B.  Use RG-58 feed line
C.  Use a reactance bridge to measure the antenna performance
from each direction around the antenna
D.  Avoid using towers higher than 30 feet above the ground

G9B  Loop antennas - physical dimensions, impedance matching,
radiation patterns, directivity and major lobes

G9B01 (B)
Approximately how long is each side of a cubical-quad antenna
driven element for 21.4 MHz?
A.  1.17 feet
B.  11.7 feet
C.  47 feet
D.  469 feet

G9B02 (A)
Approximately how long is each side of a cubical-quad antenna
driven element for 14.3 MHz?
A.  17.6 feet
B.  23.4 feet
C.  70.3 feet
D.  175 feet

G9B03 (B)
Approximately how long is each side of a cubical-quad antenna
reflector element for 29.6 MHz?
A.  8.23 feet
B.  8.7 feet
C.  9.7 feet
D.  34.8 feet

G9B04 (B)
Approximately how long is each leg of a symmetrical delta-loop
antenna driven element for 28.7 MHz?
A.  8.75 feet
B.  11.7 feet
C.  23.4 feet
D.  35 feet

G9B05 (C)
Approximately how long is each leg of a symmetrical delta-loop
antenna driven element for 24.9 MHz?
A.  10.99 feet
B.  12.95 feet
C.  13.45 feet
D.  40.36 feet

G9B06 (C)
Approximately how long is each leg of a symmetrical delta-loop
antenna reflector element for 14.1 MHz?
A.  18.26 feet
B.  23.76 feet
C.  24.35 feet
D.  73.05 feet

G9B07 (A)
Which statement about two-element delta loops and quad antennas
is true?
A.  They compare favorably with a three-element Yagi
B.  They perform poorly above HF
C.  They perform very well only at HF
D.  They are effective only when constructed using insulated wire

G9B08 (C)
Compared to a dipole antenna, what are the directional radiation
characteristics of a cubical-quad antenna?
A.  The quad has more directivity in the horizontal plane but
less directivity in the vertical plane
B.  The quad has less directivity in the horizontal plane but
more directivity in the vertical plane
C.  The quad has more directivity in both horizontal and vertical
planes
D.  The quad has less directivity in both horizontal and vertical
planes

G9B09 (D)
Moving the feed point of a multielement quad antenna from a side
parallel to the ground to a side perpendicular to the ground will
have what effect?
A.  It will significantly increase the antenna feed-point
impedance
B.  It will significantly decrease the antenna feed-point
impedance
C.  It will change the antenna polarization from vertical to
horizontal
D.  It will change the antenna polarization from horizontal to
vertical

G9B10 (C)
What does the term "antenna front-to-back ratio" mean in
reference to a delta-loop antenna?
A.  The number of directors versus the number of reflectors
B.  The relative position of the driven element with respect to
the reflectors and directors
C.  The power radiated in the major radiation lobe compared to
the power radiated in exactly the opposite direction
D.  The power radiated in the major radiation lobe compared to
the power radiated 90 degrees away from that direction

G9B11 (C)
What is the "main lobe" of a delta-loop antenna radiation
pattern?
A.  The direction of least radiation from an antenna
B.  The point of maximum current in a radiating antenna element
C.  The direction of maximum radiated field strength from the
antenna
D.  The maximum voltage standing wave point on a radiating
element

G9C  Random wire antennas - physical dimensions, impedance
matching, radiation patterns, directivity and major lobes;
feedpoint impedance of 1/2-wavelength dipole and 1/4-wavelength
vertical antennas

G9C01 (A)
What type of multiband transmitting antenna does NOT require a
feed line?
A.  A random-wire antenna
B.  A triband Yagi antenna
C.  A delta-loop antenna
D.  A Beverage antenna

G9C02 (D)
What is one advantage of using a random-wire antenna?
A.  It is more efficient than any other kind of antenna
B.  It will keep RF energy out of your station
C.  It doesn't need an impedance matching network
D.  It is a multiband antenna

G9C03 (B)
What is one disadvantage of a random-wire antenna?
A.  It must be longer than 1 wavelength
B.  You may experience RF feedback in your station
C.  It usually produces vertically polarized radiation
D.  You must use an inverted-T matching network for multiband
operation

G9C04 (D)
What is an advantage of downward sloping radials on a
ground-plane antenna?
A.  It lowers the radiation angle
B.  It brings the feed-point impedance closer to 300 ohms
C.  It increases the radiation angle
D.  It brings the feed-point impedance closer to 50 ohms

G9C05 (B)
What happens to the feed-point impedance of a ground-plane
antenna when its radials are changed from horizontal to downward-
sloping?
A.  It decreases
B.  It increases
C.  It stays the same
D.  It approaches zero

G9C06 (A)
What is the low-angle radiation pattern of an ideal
half-wavelength dipole HF antenna installed parallel to the
earth?
A.  It is a figure-eight at right angles to the antenna
B.  It is a figure-eight off both ends of the antenna
C.  It is a circle (equal radiation in all directions)
D.  It is two smaller lobes on one side of the antenna, and one
larger lobe on the other side

G9C07 (B)
How does antenna height affect the horizontal (azimuthal)
radiation pattern of a horizontal dipole HF antenna?
A.  If the antenna is too high, the pattern becomes unpredictable
B.  If the antenna is less than one-half wavelength high,
reflected radio waves from the ground significantly distort the
pattern
C.  Antenna height has no effect on the pattern
D.  If the antenna is less than one-half wavelength high,
radiation off the ends of the wire is eliminated

G9C08 (D)
If a slightly shorter parasitic element is placed 0.1 wavelength
away from an HF dipole antenna, what effect will this have on the
antenna's radiation pattern?
A.  The radiation pattern will not be affected
B.  A major lobe will develop in the horizontal plane, parallel
to the two elements
C.  A major lobe will develop in the vertical plane, away from
the ground
D.  A major lobe will develop in the horizontal plane, toward the
parasitic element

G9C09 (B)
If a slightly longer parasitic element is placed 0.1 wavelength
away from an HF dipole antenna, what effect will this have on the
antenna's radiation pattern?
A.  The radiation pattern will not be affected
B.  A major lobe will develop in the horizontal plane, away from
the parasitic element, toward the dipole
C.  A major lobe will develop in the vertical plane, away from
the ground
D.  A major lobe will develop in the horizontal plane, parallel
to the two elements

G9C10 (B)
Where should the radial wires of a ground-mounted vertical
antenna system be placed?
A.  As high as possible above the ground
B.  On the surface or buried a few inches below the ground
C.  Parallel to the antenna element
D.  At the top of the antenna


*** We (ARRL) Recommend - Do Not Use The Following Question ***

G9C11 (D)
If you are transmitting from a ground-mounted vertical antenna,
which of the following is an important reason for people to
stay away from it?
A.  To avoid skewing the radiation pattern
B.  To avoid changes to the antenna feed-point impedance
C.  To avoid excessive grid current
D.  To avoid exposure to RF radiation

******************************************


G9D  Popular antenna feed lines - characteristic impedance and
impedance matching; SWR calculations

G9D01 (A)
What factors determine the characteristic impedance of a
parallel-conductor antenna feed line?
A.  The distance between the centers of the conductors and the
radius of the conductors
B.  The distance between the centers of the conductors and the
length of the line
C.  The radius of the conductors and the frequency of the signal
D.  The frequency of the signal and the length of the line

G9D02 (B)
What is the typical characteristic impedance of coaxial cables
used for antenna feed lines at amateur stations?
A.  25 and 30 ohms
B.  50 and 75 ohms
C.  80 and 100 ohms
D.  500 and 750 ohms

G9D03 (D)
What is the characteristic impedance of flat-ribbon TV-type
twinlead?
A.  50 ohms
B.  75 ohms
C.  100 ohms
D.  300 ohms

G9D04 (C)
What is the typical cause of power being reflected back down an
antenna feed line?
A.  Operating an antenna at its resonant frequency
B.  Using more transmitter power than the antenna can handle
C.  A difference between feed-line impedance and antenna
feed-point impedance
D.  Feeding the antenna with unbalanced feed line

G9D05 (D)
What must be done to prevent standing waves of voltage and
current on an antenna feed line?
A.  The antenna feed point must be at DC ground potential
B.  The feed line must be cut to an odd number of electrical
quarter-wavelengths long
C.  The feed line must be cut to an even number of physical half-
wavelengths long
D.  The antenna feed-point impedance must be matched to the
characteristic impedance of the feed line

G9D06 (C)
If a center-fed dipole antenna is fed by parallel-conductor feed
line, how would an inductively coupled matching network be used
between the two?
A.  It would not normally be used with parallel-conductor feed
lines
B.  It would be used to increase the SWR to an acceptable level
C.  It would be used to match the unbalanced transmitter output
to the balanced parallel-conductor feed line
D.  It would be used at the antenna feed point to tune out the
radiation resistance

G9D07 (A)
If a 160-meter signal and a 2-meter signal pass through the same
coaxial cable, how will the attenuation of the two signals
compare?
A.  It will be greater at 2 meters
B.  It will be less at 2 meters
C.  It will be the same at both frequencies
D.  It will depend on the emission type in use

G9D08 (D)
In what values are RF feed line losses usually expressed?
A.  Bels/1000 ft
B.  dB/1000 ft
C.  Bels/100 ft
D.  dB/100 ft

G9D09 (A)
What standing-wave-ratio will result from the connection of a
50-ohm feed line to a resonant antenna having a 200-ohm
feed-point impedance?
A.  4:1
B.  1:4
C.  2:1
D.  1:2

G9D10 (D)
What standing-wave-ratio will result from the connection of a
50-ohm feed line to a resonant antenna having a 10-ohm feed-point
impedance?
A.  2:1
B.  50:1
C.  1:5
D.  5:1

G9D11 (D)
What standing-wave-ratio will result from the connection of a
50-ohm feed line to a resonant antenna having a 50-ohm feed-point
impedance?
A.  2:1
B.  50:50
C.  0:0
D.  1:1