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72 Cards in this Set

  • Front
  • Back
1-1. For naval communications to be effective, all involved must be top performers. Reliable, secure, and timely
receiving and transmitting of information is the goal. Which of the following requirement standards are used to determine whether or not this goal has been met?
1. Wartime
2. Peacetime
3. Cold war less 10 percent
4. Nuclear war less 25 percent
1-2. What are the two types of electrical communications?
1. Radio and wire
2. Television and wire
3. Telegraph and radio
4. Television and radio
Radio and wire
1-3. Which of the following terms includes intelligence produced by wire, radio,
visual means, oral means or
electromagnetic systems?
1. Telecommunications
2. Radiotelegraph
3. Electrolysis
4. Photocopy
1-4. Radiotelegraph (cw) is valuable when communicating to, from, and among widely separated naval units. What is the main advantage of the cw mode?
1. Cost
2. Speed
3. Security
4. Reliability
1-5. Tactical communications is usually considered as line-of-sight. What maximum distance is normally within the line-of-sight range?
1. 5 miles
2. 25 miles
3. 50 miles
4. 250 miles
25 miles
1-6. You want to transmit high-speed automatic page or tape copy across an ocean area. Which of the following
methods should you choose?
1. Facsimile
2. Radiotelegraph
3. Radiotelephone
4. Radioteletypewriter
1-7. What method is normally used to transmit graphs electronically?
1. Facsimile
2. Radio teletypewriter
3. Frequency-shift keying
4. Audio-frequency-tone shifting
1-8. When you use subdivisions to assign
reference designators to equipment, what is the designator of (a) the largest and (b) the smallest?
1. (a) System (b) set
2. (a) Set (b) unit
3. (a) Unit (b) assembly
4. (a) System (b) part
(a) Unit (b) assembly
1-9. When using the reference designator 1A6A4J6, what level does the number 1
refer to?
1. Subassembly
2. Assembly
3. Group
4. Unit
1-10. What is the total number of frequency bands the military is currently using for communications?
1. 5
2. 7
3. 9
4. 11
1-11. Extremely low-frequency transmissions are primarily directed at which of the
following users?
1. Shore installations
2. Surface ships
3. Submarines
4. Aircraft
1-12. Vlf transmitters are used primarily for which of the following purposes?
1. Navigation and fleet communications
2. Frequency standards and time signals
3. Astronomy and oscillator calibration
4. Aircraft control and space vehicle tracking
Navigation and fleet communications
1-13. Navy use of the low-frequency band is mainly for which, if any, of the following broadcasts?
1. Ship to shore
2. Fleet multichannel
3. Space vehicle telemetry
4. None of the above
Fleet multichannel
1-14. For which of the following reasons does the Navy use only the upper and lower ends of the mf band?
1. They are the most reliable
2. They produce the best propagation
3. The commercial fm band occupies the middle
4. The commercial AM band occupies the middle
The commercial fm band occupies the middle
1-15. Hf communications over long-distance trunks, or links between fixed terminals
are examples of which of the following types of systems?
1. Fleet broadcast
2. Point-to-point
3. Ground-to-air
4. Ship-to-shore
1-16. Sending a message on several frequencies at once is an example of which of the following transmission types?
1. Time-diversity
2. Phase-diversity
3. Distance-diversity
4. Frequency-diversity
1-17. What type of diversity uses physically separated transmit or receive antennas to improve communications?
1. Time
2. Phase
3. Space
4. Frequency
1-18. Normally the transmission range of vhf is
limited to line of sight. What technique is used to increase this range?
1. Tropospheric scatter
2. Atmospheric diversity
3. Ionospheric maneuvering
4. Each of the above
Tropospheric scatter
1-19. A complex of links make up a major communications system. The naval
communications system is further broken down into what two groups?
1. Strategic and local
2. World-wide and local
3. Strategic and tactical
4. Tactical and world-wide
Strategic and tactical
1-20. Communications links have many modes of operation. One terminal in a link has
its equipment setup in simplex. The other terminal is using two channels or
frequencies in a configuration that allows
sending and receiving of different messages at the same time. These two
terminals working together make up what mode of operation?
1. Full duplex
2. Half duplex
3. Quasiduplex
4. Semiduplex
1-21. What communications link mode of operation provides telecommunications
capability between stations at the same time in both directions?
1. Half duplex
2. Semiduplex
3. Broadcast
4. Duplex
1-22. Aid in restoring downed fleet communications channels is furnished on a not-to-interfere basis by which of the following networks?
1-23. Which of the following switched networks extends tactical voice to shorebased
operational commands?
1-24. Of the following transmitter types, which are used for basic communications?
1. Cw, AM, fm, and ssb
2. Fsk, cw, AM, and tty
3. Cw, ssb, voice and fm
4. Voice, tty, fsk, and AM
Cw, AM, fm, and ssb
1-25. Cw transmissions have narrow bandwidths and a high degree of intelligibility under severe noise conditions. What is the primary Navy use for cw?
1. Radioteletypewriter
2. Radiotelegraphy
3. Facsimile
4. Voice
1-26. A cw transmitter must contain which of the following components?
1. A traveling-wave tube
2. A demodulator
3. A combiner
4. A keyer
A keyer
1-27. In a cw transmitter, a buffer stage performs which of the following functions?
1. Current divider
2. Voltage divider
3. Current amplifier
4. Voltage amplifier
Voltage amplifier
1-28. There are differences between low- and high-power transmitters. The main
difference is the high power transmitter contains a larger number of which of the
following types of amplifiers?
1. Oscillator
2. Final power
3. Intermediate power
4. Intermediate frequency
Intermediate power
1-29. In an AM transmitter, audio frequencies are converted into corresponding
electrical energy by which of the following components?
1. An oscillator
2. A microphone
3. A modulator
4. A headset
A microphone
1-30. In an fm transmitter, a varicap performs which of the following functions?
1. It amplifies the outgoing signal
2. It varies the oscillator frequency
3. It demodulates the outgoing signal
4. It multiplies the oscillator frequency
It varies the oscillator frequency
1-31. If an oscillator has a fundamental frequency of 3,550 megahertz, what is
the frequency of the third harmonic?
1. 5,325 megahertz
2. 7,100 megahertz
3. 9,875 megahertz
4. 10,650 megahertz
10,650 megahertz
1-32. If the fundamental frequency of an rf carrier is 1,000 kilohertz, what is the
frequency of the fourth subharmonic?
1. 500 kilohertz
2. 333 kilohertz
3. 250 kilohertz
4. 200 kilohertz
250 kilohertz
1-33. Oscillator output frequencies are raised to usable values by frequency
multipliers. To raise an oscillatorm frequency from 20 megahertz to 120 megahertz, what combination of frequency multipliers would be used?
1. Two doublers
2. A doubler and a tripler
3. A doubler and a quadruplet
4. A tripler and a quadruplet
A doubler and a tripler
1-34. When an AM signal leaves the antenna of a transmitter, which of the following frequency components does the signal
1. The carrier
2. The upper sideband
3. The lower sideband
4. All of the above
All of the above
In a single-sideband transmitter, selection of the desired sideband and suppression of the other is done by which of the
following components?
1. Mixer
2. Filter
3. Detector
4. Oscillator
When compared to a conventional AM signal, an ssb signal provides which of
the following advantages?
1. Improved frequency stability
2. Increased receiver gain
3. Reduced distortion
4. Reduced bandwidth
Reduced bandwidth
1-37. For ship-to-shore teletypewriter circuits,
which of the following types of multiplexing is/are used?
1. Time and/or phase
2. Time and/or frequency
3. Phase and/or modulation
4. Frequency and/or modulation
Time and/or frequency
1-38. Operators of transmitters and receivers
use a circuit to coordinate the service of messages and to make frequency changes. What is the name of this
1. Order-wire circuit
2. Documentation circuit
3. Synchronization circuit
4. Operator-eyes-only circuit
Order-wire circuit
1-39. A transmitted electromagnetic wave
enters an antenna, induces a voltage into it, and passes that voltage to a receiver.
What is this chain of events called?
1. Reproduction
2. Selection
3. Detection
4. Reception
1-40. When a receiver picks one frequency out from all other frequencies, it's
performing which of the following basic functions?
1. Selection
2. Reception
3. Detection
4. Reproduction
1-41. When a receiver separates the audio
frequencies from the radio-frequency carrier it is performing which of the
following basic functions?
1. Reception
2. Selection
3. Detection
4. Reproduction
1-42. The receiver action of converting electrical energy to a usable format, such as sound, is an example of which of the following basic functions?
1. Reception
2. Selection
3. Detection
4. Reproduction
1-43. Which of the following measurements provides an indication of the ability of a
receiver to reproduce weak signals?
1. Bandwidth
2. Sensitivity
3. Selectivity
4. Frequency response
1-44. Overall sensitivity of a receiver is limited by which of the following factors?
1. Noise
2. Bandwidth
3. Output power
4. Frequency response
1-45. How is a receiver's ability to reject unwanted signals and receive desired
signals determined?
1. Noise
2. Fidelity
3. Selectivity
4. Sensitivity
1-46. When high fidelity is your prime consideration you should select a receiver that has been designed with which of the following features?
1. High gain
2. High output power
3. Broadband frequency selection circuits
4. Narrowband frequency selection circuits
Broadband frequency selection circuits
1-47. The IF frequency in a receiver is produced by which of the following methods?
1. Modulation
2. Heterodyning
3. Frequency synthesis
4. Frequency multiplication
1-48. The process of heterodyning takes place
in which of the following receiver circuits?
1. Mixer
2. Comparator
3. Oscillator
4. Second IF amplifier
1-49. Of the following frequencies, which one is a typical value of IF for AM
communications receivers?
1. 455 kilohertz
2. 554 kilohertz
3. 455 megahertz
4. 554 megahertz
455 kilohertz
1-50. Two or more circuits within a receiver are varied by a single control through the use of which of the following processes?
1. Ganged tuning
2. Frequency synthesis
3. Automatic gain control
4. Automatic frequency control
Ganged tuning
1-51. There are electrical differences between AM and fm receivers. An fm receiver
contains which of the following circuits?
1. Comparator
2. Discriminator
3. Limiter
4. Both 2 and 3 above
Both 2 and 3 above
1-52. An fm signal has which of the following
characteristics when compared to an AM signal?
1. More noise
2. Less static
3. A higher power output
4. A lower operating frequency
Less static
1-53. Ssb transmissions have which of the following characteristics when compared
to AM transmissions?
1. Wide bandpass frequencies
2. Concentrated power
3. Less modulation
4. High fidelity
Concentrated power
1-54. Single sideband receivers use a special
oscillator. The output of that oscillator is fed directly to the detector circuit. What type of oscillator is used?
1. Local
2. High frequency
3. Variable frequency
4. Carrier reinsertion
Carrier reinsertion
1-55. A transmitter has a suppressed carrier frequency of 4 megahertz and is radiating only an upper sideband signal. When the
intelligence is a 1-kilohertz tone, which of the following sideband frequencies will be transmitted?
1. 3,999 kilohertz
2. 4,000 kilohertz
3. 4,001 kilohertz
4. Both 2 and 3 above
4,001 kilohertz
1-56. Manual gain lets you adjust a receiver for maximum sensitivity and amplify weak
input signals. Which of the following internal sections of the receiver are varied by this control?
1. Oscillator
2. Audio frequency
3. Radio frequency
4. Intermediate frequency
Radio frequency
1-57. Manual volume control of a receiver internally varies the input to which of the following circuits?
1. Detector
2. Audio amplifier
3. Frequency converter
4. Radio frequency amplifier
Audio amplifier
1-58. Changes in receiver input strength due to changing atmospheric conditions is described by which of the following
1. Gain
2. Fading
3. Ducting
4. Trapping
1-59. The rf amplifier connected to your receiving antenna has a voltage gain of
240. When the antenna is receiving a signal of 8 microvolts, what will be the
maximum output voltage of the rf amplifier?
1. 1.92 millivolts
2. 2.91 microvolts
3. 30 microvolts
4. 33 millivolts
1.92 millivolts
1-62. To automatically compensate for input signal strength variations within a
receiver, which of the following types of circuits are added?
1. Afc
2. Nfc
3. Agc
4. Nsu
1-63. AgC circuitry within a receiver uses a portion of which of the following
detector voltage components as a feedback signal to preceding stages?
1. Dc
2. Ac
3. IF
4. Audio
1-64. Which of the following types of agc voltage drives an amplifier toward cutoff?
1. Saturation
2. Delayed
3. Reverse
4. Forward
1-65. What is the purpose of the squelch circuit in a receiver?
1. To attenuate very strong signals in order to prevent their overdriving the
remaining stages in the receiver
2. To suppress receiver noise output when no input signal is being received
3. To suppress the electronic "whine" of the rf amplification stage
4. To reject signals of other than the desired frequency should the receiver drift off frequency
To suppress receiver noise output when no input signal is being received
1-66. How does a receiver accomplish the squelch function?
1. By proportional blocking of the rf amplifier stage output
2. By blocking the detector or audio amplifier when there is no signal
3. By switching an inductive/capacitive
filter into the output of the last rf amplifier
4. By switching in a matched-frequency stage which passes matching frequencies and rejects all others
By blocking the detector or audio amplifier when there is no signal
1-67. A quartz crystal filter is used in a communications receiver to improve which of the following characteristics?
1. Fidelity
2. Sensitivity
3. Selectivity
4. Reproduction
1-68. When the wiper of R1 is placed in the full treble position, which of the
following actions occur?
1. Bass response is improved
2. High frequency shunting is reduced
3. Higher frequencies are shunted to
4. The capacitor and resistor are placed
in parallel
High frequency shunting is reduced
1-69. Automatic frequency control circuits are used in a receiver for which of the
following purposes?
1. To adjust IF amplifier gain
2. To correct for oscillator frequency drift
3. To extend the frequency range of the receiver
4. To automatically tune the receiver to the desired frequency
To correct for oscillator frequency drift
1-71. A change in oscillator frequency will change which of the following input
relationships between the sawtooth reference voltage and the incoming signal?
1. Phase
2. Voltage
3. Current
4. Amplitude
1-72. How is the long term stability and accuracy required of modern
communications receivers attained?
1. Through the use of a single, crystalcontrolled
oscillator, as the local
2. Through the use of an electroncoupled oscillator, as the local oscillator
3. Through a process of automatic frequency control
4. Through a process known as
frequency synthesis
Through a process known as
frequency synthesis
1-73. When using the frequency synthesis process, a signal of the desired accuracy and stability is produced by which, if any, of the following methods?
1. Automatic frequency control, that is, by sensing the difference between the
oscillator frequency and the desired frequency and automatically compensating for this difference
2. Using a crystal-controlled oscillator to produce a stable high frequency, and through the process of frequency division selecting a subharmonic of this frequency as the desired
3. The heterodyning and selection of frequencies which are not harmonically related to each other
4. None of the above
The heterodyning and selection of frequencies which are not harmonically related to each other
1-74. Permanent magnet speakers respond quite well to which of the following
audio frequency ranges?
1. Low
2. High
3. Mid band
4. Each of the above
1-75. For which of the following reasons do most standard Navy headphones respond poorly to low frequencies?
1. Small diaphragm size
2. Diaphragm inflexibility
3. Both 1 and 2 above
4. Input signal filtering
Both 1 and 2 above