SUBELEMENT E4 -- AMATEUR RADIO PRACTICES
[5 Exam Questions -- 5
Groups]
E4A Test equipment: spectrum analyzers
(interpreting spectrum
analyzer displays; transmitter output spectrum); logic probes
(indications of high and low states in digital circuits; indications
of
pulse conditions in digital circuits)
E4A01
(C)
How
does a spectrum analyzer differ from a conventional time-domain oscilloscope?
A. A spectrum analyzer measures ionospheric
reflection; an oscilloscope displays electrical signals
B. A spectrum analyzer displays signals in the
time domain; an oscilloscope displays signals in the frequency domain
C. A spectrum analyzer
displays signals in the frequency domain; an oscilloscope displays signals in
the time domain
D. A spectrum analyzer displays radio
frequencies; an oscilloscope displays audio frequencies
E4A02
(D)
What
does the horizontal axis of a spectrum analyzer display?
A. Amplitude
B. Voltage
C. Resonance
D. Frequency
E4A03
(A)
What
does the vertical axis of a spectrum analyzer display?
A. Amplitude
B. Duration
C. Frequency
D. Time
E4A04
(A)
Which
test instrument is used to display spurious signals from a radio transmitter?
A. A spectrum analyzer
B. A wattmeter
C. A logic analyzer
D. A time-domain reflectometer
E4A05
(B)
Which
test instrument is used to display intermodulation distortion products from an
SSB transmitter?
A. A wattmeter
B. A spectrum analyzer
C. A logic analyzer
D. A time-domain reflectometer
E4A06
(C)
Which
of the following is NOT something you would determine with a spectrum analyzer?
A. The degree of isolation between the input
and output ports of a 2- meter duplexer
B. Whether a crystal is operating on its
fundamental or overtone frequency
C. The speed at which a
transceiver switches from transmit to receive when being used for packet radio
D. The spectral output of a transmitter
E4A07
(B)
What is
an advantage of using a spectrum analyzer to observe the output from a VHF
transmitter?
A. There are no advantages; an inexpensive
oscilloscope can display the same information
B. It displays all frequency
components of the transmitted signal
C. It displays a time-varying representation of
the modulation envelope
D. It costs much less than any other
instrumentation useful for such measurements
E4A08
(D)
What
advantage does a logic probe have over a voltmeter for monitoring the status of
a logic circuit?
A. It has many more leads to connect to the
circuit than a voltmeter
B. It can be used to test analog and digital
circuits
C. It can read logic circuit voltage more
accurately than a voltmeter
D. It is smaller and shows a
simplified readout
E4A09
(C)
Which
test instrument is used to directly indicate high and low digital states?
A. An ohmmeter
B. An electroscope
C. A logic probe
D. A Wheatstone bridge
E4A10
(D)
What
can a logic probe indicate about a digital logic circuit?
A. A short-circuit fault
B. An open-circuit fault
C. The resistance between logic modules
D. The high and low logic
states
E4A11
(A)
Which
test instrument besides an oscilloscope is used to indicate pulse conditions in
a digital logic circuit?
A. A logic probe
B. An ohmmeter
C. An electroscope
D. A Wheatstone bridge