Neets Mod 21 Ch 5

Front 1

When using the two-tone test
(trapezoidal method) to check a transmitter, you should see what pattern on the oscilloscope?
1. A series of fully modulated sine waves
2. A 100% amplitude-modulated signal
3. Two pulses of equal amplitude and duration
4. Two opposing triangles that are mirror images of each other

Back 1

Two opposing triangles that are mirror images of each other

Front 2

Frequency deviation of an fm signal is usually expressed in which of the following units of measurements?
1. Kilohertz
2. dB
3. dBm
4. Volts

Back 2

Kilohertz

Front 3

What limits an fm transmitter’s maximum frequency deviation?
1. The width of the band assigned for station operation
2. The maximum power output rating of the transmitter
3. The distortion that occurs at 100% modulation
4. The transmitting antenna height

Back 3

1. The width of the band assigned for station operation

Front 4

Spectrum analysis is a graphic plot of
1. amplitude versus time
2. time versus frequency
3. amplitude versus frequency
4. amplitude versus power

Back 4

3. amplitude versus frequency

Front 5

Time-domain plots are used by
technicians to graphically view which of the following waveform parameters?
1. Amplitude versus time
2. Frequency versus time
3. Frequency versus distance
4. Amplitude versus power

Back 5

1. Amplitude versus time

Front 6

Frequency-domain plots are used by technicians to graphically view which of the following waveform parameters?
1. Amplitude versus time
2. Amplitude versus frequency
3. Frequency versus distance
4. Amplitude versus power

Back 6

2. Amplitude versus frequency

Front 7

3-53. Which of the following pieces of test equipment should you use to determine
what signals make up a complex signal?
1. Oscilloscope
2. Sweep oscillator
3. Spectrum analyzer
4. Time-domain reflectometer

Back 7

3. Spectrum analyzer

Front 8

At 100% amplitude modulation, the total
power in the sidebands equals what
percentage of the carrier power?
1. 6%
2. 50%
3. 66%
4. 100%

Back 8

3. 66%

Front 9

When viewing a 100% amplitude modulated signal with a spectrum analyzer, what type of display should you observe?
1. A center frequency and both the upper and lower sidebands 6 dB down from the center frequency
2. A center frequency and both the upper and lower sidebands of equal amplitude
3. A center frequency that is -6 dB down from both the upper and lower sidebands
4. A suppressed carrier with both the upper and lower sidebands of equal amplitude

Back 9

1. A center frequency and both the upper and lower sidebands 6 dB down from the center frequency

Front 10

Which of the following is/are an
advantage of ssb transmission?
1. The voice quality of ssb transmissions
is superior to both AM and fm
transmissions
2. Ssb transmissions are not susceptible
to interference caused by sun spots
and atmospherics
3. Ssb requires one-sixth of the output power and less than half the bandwidth required by AM to transmit the same amount of intelligence power
4. All of the above

Back 10

3. Ssb requires one-sixth of the output power and less than half the bandwidth required by AM to transmit the same amount of intelligence power

Front 11

In fm, the AMOUNT of frequency
deviation (shift) is proportional to
1. the frequency of the carrier
2. the amplitude of the modulating signal
3. the frequency of the modulating signal
4. the plate current of the transmitter’s linear amplifier

Back 11

2. the amplitude of the modulating signal

Front 12

In fm, the RATE of frequency deviation (shift) is proportional to
1. the impedance of the antenna
2. the power output of the transmitter
3. the amplitude of the modulating signal
4. the frequency of the modulating signal

Back 12

4. the frequency of the modulating signal

Front 13

When analyzing the composition of a rectangular wave with a spectrum analyzer, which of the following types of
displays will you see?
1. A fundamental frequency and its odd harmonics only
2. A fundamental frequency and its even harmonics only
3. A fundamental frequency and its combined even and odd harmonics
4. An infinite number of fundamental frequencies

Back 13

3. A fundamental frequency and its combined even and odd harmonics

Front 14

The ability of a spectrum analyzer to resolve signals refers to its ability to
1. distinguish one signal from other signals
2. shape signals through the use of filters
3. determine a receiver’s minimum discernible signal
4. measure the frequency of a signal

Back 14

3. determine a receiver’s minimum discernible signal

Front 15

The ability of a spectrum analyzer to resolve signals is limited by which of the following factors?
1. The amplitude of the signal under test
2. The narrowest bandwith of the spectrum analyzer
3. The upper frequency limits of the spectrum analyzer
4. The lower frequency limits of the spectrum analyze

Back 15

2. The narrowest bandwith of the spectrum analyzer

Front 16

Which of the following characteristics of a transmission line fault can be observed using time-domain reflectometry?
1. Nature of the fault
2. Distance to the fault
3. Both 1 and 2 above
4. Figure of merit of the fault

Back 16

3. Both 1 and 2 above

Front 17

What is the primary application of swept frequency
testing?
1. To determine the broadband
frequency response of a device
2. To determine the characteristics of a device at a specific frequency
3. To determine the impedance of a transmission line
4. To determine the swr of a
transmission line

Back 17

1. To determine the broadband
frequency response of a devic

Front 18

You should perform an initial power check on a transmitting antenna before sweeping the antenna for which of the following reasons?
1. To prevent damage to the test equipment
2. To ensure the transmitter is deenergized
3. To ensure the transmitter is energized
4. To ensure the transmitter is keyed

Back 18

1. To prevent damage to the test equipment