E4A: Test equipment: analog and digital instruments; spectrum and network analyzers, antenna analyzers; oscilloscopes; testing transistors; RF measurements
E4A01:
How does a spectrum analyzer differ from a conventional oscilloscope?
A spectrum analyzer displays signals in the frequency domain; an oscilloscope displays signals in the time domain
A spectrum analyzer measures ionospheric reflection; an oscilloscope displays electrical signals
A spectrum analyzer displays the peak amplitude of signals; an oscilloscope displays the average amplitude of signals
A spectrum analyzer displays radio frequencies; an oscilloscope displays audio frequencies
E4A02:
Which of the following parameters would a typical spectrum analyzer display on the horizontal axis?
Frequency
SWR
Q
Time
E4A03:
Which of the following parameters would a typical spectrum analyzer display on the vertical axis?
Amplitude
Duration
SWR
Q
E4A04:
Which of the following test instruments is used to display spurious signals from a radio transmitter?
A spectrum analyzer
A wattmeter
A logic analyzer
A time-domain reflectometer
E4A05:
Which of the following test instruments is used to display intermodulation distortion products in an SSB transmission?
A spectrum analyzer
A wattmeter
A logic analyzer
A time-domain reflectometer
E4A06:
Which of the following could be determined with a spectrum analyzer?
All of these choices are correct
The degree of isolation between the input and output ports of a 2 meter duplexer
Whether a crystal is operating on its fundamental or overtone frequency
The spectral output of a transmitter
E4A07:
Which of the following is an advantage of using an antenna analyzer vs. a SWR bridge to measure antenna SWR?
Antenna analyzers typically do not need an external RF source
Antenna analyzers automatically tune your antenna for resonance
Antenna analyzers typically display a time-varying representation of the modulation envelope
All of these answers are correct
E4A08:
Which of the following instruments would be best for measuring the SWR of a beam antenna?
An antenna analyzer
A spectrum analyzer
A Q meter
An ohmmeter
E4A09:
Which of the following is most important when adjusting PSK31 transmitting levels?
ALC level
Power output
PA current
SWR
E4A10:
Which of the following is a useful test for a functioning NPN transistor in an active circuit where the transistor should be biased "on" ?
Measure base-to-emitter voltage with a voltmeter; it should be approximately 0.6 to 0.7 volts
Measure base-to-emitter resistance with an ohmmeter; it should be approximately 6 to 7 ohms
Measure base-to-emitter resistance with an ohmmeter; it should be approximately 0.6 to 0.7 ohms
Measure base-to-emitter voltage with a voltmeter; it should be approximately 6 to 7 volts
E4A11:
Which of the following test instruments can be used to indicate pulse conditions in a digital logic circuit?
A logic probe
An ohmmeter
An electroscope
A Wheatstone bridge
E4A12:
Which of the following procedures is an important precaution to follow when connecting a spectrum analyzer to a transmitter output?
Attenuate the transmitter output going to the spectrum analyzer
Use high quality double shielded coaxial cables to reduce signal losses
Match the antenna to the load
All of these choices are correct
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