ELEMENT 2 - TECHNICIAN CLASS
Question Pool
SUBELEMENT T4 -- AMATEUR RADIO PRACTICES
[4 Exam Questions -- 4 Groups] T4A Lightning protection
and station grounding; safety interlocks, antenna installation safety
procedures; dummy antennas T4A01 (C)
How can an antenna system best be protected from
lightning damage? A. Install a balun at the antenna feed
point
B. Install an RF choke in the antenna feed line C.
Ground all antennas when they are not in use D. Install a fuse in the
antenna feed line T4A02 (D)
How can amateur station equipment best be protected
from lightning damage? A. Use heavy insulation on the
wiring
B. Never turn off the equipment
C. Disconnect the ground system
from all radios D. Disconnect all equipment from the power
lines and antenna cables T4A03 (B)
For best protection from electrical
shock, what should be grounded in an amateur station? A.
The power supply primary B. All station equipment C.
The antenna feed line
D. The AC power mains T4A04 (D)
Why would there
be an interlock switch in a high-voltage power supply to turn off the power if
its cabinet is opened? A. To keep dangerous RF radiation
from leaking out through an open cabinet
B. To keep dangerous RF radiation
from coming in through an open cabinet
C. To turn the power supply off when
it is not being used D. To keep anyone opening the cabinet
from getting shocked by dangerous high voltages T4A05 (C)
Why should you
wear a hard hat and safety glasses if you are on the ground helping someone work
on an antenna tower? A. So you won’t be hurt if the tower
should accidentally fall
B. To keep RF energy away from your head during
antenna testing C. To protect your head from something
dropped from the tower D. So someone passing by will know that work is
being done on the tower and will stay away T4A06 (D)
What safety factors must you
consider when using a bow and arrow or slingshot and weight to shoot an
antenna-support line over a tree? A. You must ensure that
the line is strong enough to withstand the shock of shooting the weight
B.
You must ensure that the arrow or weight has a safe flight path if the line
breaks
C. You must ensure that the bow and arrow or slingshot is in good
working condition D. All of these choices are correct
T4A07 (B)
Which of the following is the best way to install your
antenna in relation to overhead electric power lines? A.
Always be sure your antenna wire is higher than the power line, and crosses it
at a 90-degree angle B. Always be sure your antenna and feed
line are well clear of any power lines C. Always be sure your antenna is
lower than the power line, and crosses it at a small angle
D. Only use
vertical antennas within 100 feet of a power line T4A08 (B)
What device is
used in place of an antenna during transmitter tests so that no signal is
radiated? A. An antenna matcher B. A
dummy antenna C. A low-pass filter
D. A decoupling resistor
T4A09 (A)
Why would you use a dummy antenna? A. For off-the-air transmitter testing B. To reduce output
power
C. To give comparative signal reports
D. To allow antenna tuning
without causing interference T4A10
(A)
What minimum rating should a dummy antenna have
for use with a 100 watt single-sideband phone transmitter? A. 100 watts continuous B. 141 watts
continuous
C. 175 watts continuous
D. 200 watts continuous
T4A11 (B)
Would a 100 watt light bulb make a good dummy load for tuning a transceiver?
A. Yes; a light bulb behaves exactly like a dummy load
B. No; the impedance of the light bulb changes as the
filament gets hot C. No; the light bulb would act like an open circuit
D. No; the light bulb would act like a short circuit T4B Electrical wiring, including switch location, dangerous voltages
and currents; SWR meaning and measurements; SWR meters T4B01 (C)
Where should the
green wire in a three-wire AC line cord be connected in a power supply?
A. To the fuse
B. To the "hot" side of the power switch
C. To the chassis D. To the white wire
T4B02 (A)
What is the minimum voltage that is usually dangerous to humans?
A. 30 volts B. 100 volts
C.
1000 volts
D. 2000 volts T4B03
(A)
How much electrical current flowing through the
human body will probably be fatal? A.
As little as 1/10 of an ampere B. Approximately 10 amperes
C. More
than 20 amperes
D. Current through the human body is never fatal
T4B04 (A)
Which body organ can be fatally affected by a very small amount of
electrical current? A. The heart
B. The brain
C. The liver
D. The lungs T4B05 (C)
What does an SWR
reading of less than 1.5:1 mean? A. An impedance match that
is too low
B. An impedance mismatch; something may be wrong with the antenna
system C. A fairly good impedance match D. An antenna
gain of 1.5 T4B06 (A)
What does a very high SWR reading mean? A. The antenna is the wrong length, or there may be
an open or shorted connection somewhere in the feed line B. The signals
coming from the antenna are unusually strong, which means very good radio
conditions
C. The transmitter is putting out more power than normal, showing
that it is about to go bad
D. There is a large amount of solar radiation,
which means very poor radio conditions T4B07 (B)
If an SWR reading at the low
frequency end of an amateur band is 2.5:1, increasing to 5:1 at the high
frequency end of the same band, what does this tell you about your ½-wavelength
dipole antenna? A. The antenna is broadbanded B. The antenna is too long for operation on the band C. The
antenna is too short for operation on the band
D. The antenna is just right
for operation on the band T4B08
(C)
If an SWR reading at the low frequency end of an
amateur band is 5:1, decreasing to 2.5:1 at the high frequency end of the same
band, what does this tell you about your ½-wavelength dipole antenna?
A. The antenna is broadbanded
B. The antenna is too
long for operation on the band C. The antenna is too short
for operation on the band D. The antenna is just right for operation on
the band T4B09 (D)
What instrument is used to measure the relative
impedance match between an antenna and its feed line? A. An
ammeter
B. An ohmmeter
C. A voltmeter D. An SWR
meter T4B10 (C)
If you use an SWR meter designed to operate on 3-30 MHz
for VHF measurements, how accurate will its readings be? A.
They will not be accurate
B. They will be accurate enough to get by C. If it properly calibrates to full scale in the set position,
they may be accurate D. They will be accurate providing the readings are
multiplied by 4.5 T4B11 (B)
What does an SWR reading of 1:1 mean? A. An antenna for another frequency band is probably connected B. The best impedance match has been attained C. No power
is going to the antenna
D. The SWR meter is broken T4C Meters and their placement in circuits, including volt, amp,
multi, peak-reading and RF watt; ratings of fuses and switches T4C01 (B)
How is a
voltmeter usually connected to a circuit under test? A. In
series with the circuit B. In parallel with the circuit
C. In quadrature with the circuit
D. In phase with the circuit
T4C02 (A)
How is an ammeter usually connected to a circuit under test? A. In series with the circuit B. In parallel
with the circuit
C. In quadrature with the circuit
D. In phase with the
circuit T4C03 (A)
Where should an RF wattmeter be connected for the most
accurate readings of transmitter output power? A. At the transmitter output connector B. At the antenna
feed point
C. One-half wavelength from the transmitter output
D.
One-half wavelength from the antenna feed point T4C04 (D)
For which
measurements would you normally use a multimeter? A. SWR
and power
B. Resistance, capacitance and inductance
C. Resistance and
reactance D. Voltage, current and resistance
T4C05 (B)
What might happen if you switch a multimeter to measure
resistance while you have it connected to measure voltage? A. The multimeter would read half the actual voltage B. It would probably destroy the meter circuitry C. The
multimeter would read twice the actual voltage
D. Nothing unusual would
happen; the multimeter would measure the circuit’s resistance
T4C06 (C)
If you switch a multimeter to read microamps and connect it into a circuit
drawing 5 amps, what might happen? A. The multimeter would
read half the actual current
B. The multimeter would read twice the actual
current C. It would probably destroy the meter circuitry
D. The multimeter would read a very small value of current
T4C07 (B)
At what line impedance do most RF watt meters usually operate? A. 25 ohms B. 50 ohms C. 100 ohms
D. 300
ohms T4C08 (A)
What does a directional wattmeter measure? A. Forward and reflected power B. The
directional pattern of an antenna
C. The energy used by a transmitter
D.
Thermal heating in a load resistor T4C09 (B)
If a directional RF wattmeter reads
90 watts forward power and 10 watts reflected power, what is the actual
transmitter output power? A. 10 watts B. 80 watts C. 90 watts
D. 100 watts
T4C10 (A)
Why might you use a peak-reading RF wattmeter at your station? A. To make sure your transmitter’s output power is
not higher than that authorized by your license class B. To make sure
your transmitter is not drawing too much power from the AC line
C. To make
sure all your transmitter’s power is being radiated by your antenna
D. To
measure transmitter input and output power at the same time T4C11 (C)
What could happen
to your transceiver if you replace its blown 5 amp AC line fuse with a 30 amp
fuse? A. The 30-amp fuse would better protect your
transceiver from using too much current
B. The transceiver would run cooler
C. The transceiver could use more current than 5 amps and a
fire could occur D. The transceiver would not be able to produce as much
RF output T4D RFI and its complications,
resolution and responsibility T4D01 (C)
What is meant by receiver overload? A. Too much voltage from the power supply
B. Too much current from
the power supply C. Interference caused by strong signals
from a nearby source D. Interference caused by turning the volume up too
high T4D02 (A)
What is meant by harmonic radiation? A. Unwanted signals at frequencies that are
multiples of the fundamental (chosen) frequency B. Unwanted signals that
are combined with a 60-Hz hum
C. Unwanted signals caused by sympathetic
vibrations from a nearby transmitter
D. Signals that cause skip propagation
to occur T4D03 (B)
What type of filter might be connected to an amateur HF
transmitter to cut down on harmonic radiation? A. A
key-click filter B. A low-pass filter C. A high-pass
filter
D. A CW filter T4D04
(C)
If your neighbor reports television interference
whenever you are transmitting from your amateur station, no matter what
frequency band you use, what is probably the cause of the interference?
A. Too little transmitter harmonic suppression
B.
Receiver VR tube discharge C. Receiver overload D.
Incorrect antenna length T4D05
(D)
If your neighbor reports television interference
on one or two channels only when you are transmitting on the 15-meter band, what
is probably the cause of the interference? A. Too much
low-pass filtering on the transmitter
B. De-ionization of the ionosphere
near your neighbor’s TV antenna
C. TV receiver front-end overload D. Harmonic radiation from your transmitter
T4D06 (B)
What type of filter should be connected to a TV
receiver as the first step in trying to prevent RF overload from an amateur HF
station transmission? A. Low-pass B.
High-pass C. Band pass
D. Notch T4D07 (B)
What first step should be taken at
a cable TV receiver when trying to prevent RF overload from an amateur HF
station transmission? A. Install a low-pass filter in the
cable system transmission line B. Tighten all connectors and
inspect the cable system transmission line C. Make sure the center
conductor of the cable system transmission line is well grounded
D. Install
a ceramic filter in the cable system transmission line T4D08 (C)
What effect might
a break in a cable television transmission line have on amateur communications?
A. Cable lines are shielded and a break cannot affect
amateur communications
B. Harmonic radiation from the TV receiver may cause
the amateur transmitter to transmit off-frequency C. TV
interference may result when the amateur station is transmitting, or
interference may occur to the amateur receiver D. The broken cable may
pick up very high voltages when the amateur station is transmitting
T4D09 (A)
If you are told that your amateur station is causing television
interference, what should you do? A.
First make sure that your station is operating properly, and that it does not
cause interference to your own television B. Immediately turn off your
transmitter and contact the nearest FCC office for assistance
C. Connect a
high-pass filter to the transmitter output and a low-pass filter to the
antenna-input terminals of the television
D. Continue operating normally,
because you have no reason to worry about the interference T4D10 (C)
If harmonic
radiation from your transmitter is causing interference to television receivers
in your neighborhood, who is responsible for taking care of the interference?
A. The owners of the television receivers are responsible
B. Both you and the owners of the television receivers share the
responsibility C. You alone are responsible, since your
transmitter is causing the problem D. The FCC must decide if you or the
owners of the television receivers are responsible T4D11 (D)
If signals from
your transmitter are causing front-end overload in your neighbor’s television
receiver, who is responsible for taking care of the interference? A. You alone are responsible, since your transmitter is causing the
problem
B. Both you and the owner of the television receiver share the
responsibility
C. The FCC must decide if you or the owner of the television
receiver are responsible D. The owner of the television
receiver is responsible
END OF SUB-ELEMENT T4