CDC 3d153 volume 2 v2 (april 2013)

100 Questions  I  By Mmikhaylevskiy
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CDC Quizzes & Trivia
CDC 3D153 01 1206, Edit Code 02 (April 2013) Volume 2 Units 1-5 Unit 1: Antenna Theory Unit 2: Electromagnetic Wave Theory Unit 3: Transmission Security Techniques, Data Linking Concepts and Jam-Resistant Communications Unit 4: Other RF Transmission Systems Unit 5: High Frequency Communications

  
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  • 1. 
    Equipment used for generating, amplifying, and transmitting RF carrier is collectively called
    • A. 

      A receiver.

    • B. 

      An antenna.

    • C. 

      A transmitter.

    • D. 

      A transmission line.


  • 2. 
    What basic receiver function involves having the transmitted electromagnetic wave pass through the receive antenna in such a manner as to induce a voltage in the antenna?
    • A. 

      Reproduction.

    • B. 

      Reception.

    • C. 

      Detection.

    • D. 

      Selection.


  • 3. 
    The ability of a receiver to reproduce the signal of a very weak station is the characteristic of the receiver’s
    • A. 

      Fidelity.

    • B. 

      Capacity.

    • C. 

      Sensitivity.

    • D. 

      Selectivity.


  • 4. 
    The ability to reproduce the input signal accurately is the characteristics of the receiver’s
    • A. 

      Fidelity.

    • B. 

      Capacity.

    • C. 

      Sensitivity.

    • D. 

      Selectivity.


  • 5. 
    Which of the following CANNOT be performed by the transceiver’s computerized components and micro-circuitry?
    • A. 

      Specific equipment faults.

    • B. 

      Internal equipment tests.

    • C. 

      Internal calibrations.

    • D. 

      Repair itself.


  • 6. 
    Resistance of the conductor material in a transmission line leads to which type of loss?
    • A. 

      Copper.

    • B. 

      Radiation.

    • C. 

      Inductive.

    • D. 

      Skin-effect.


  • 7. 
    Leakage loss in a transmission line can be minimized by using a
    • A. 

      Thinner conductor.

    • B. 

      Thicker conductor.

    • C. 

      Very low-resistance dielectric.

    • D. 

      Very high-resistance dielectric.


  • 8. 
    A transmission line that consists of a center conductor placed inside a rigid metal tube functioning as the outer tube is called a
    • A. 

      Flexible coaxial cable.

    • B. 

      Rigid coaxial cable.

    • C. 

      Waveguide.

    • D. 

      Twin lead.


  • 9. 
    Which statement concerning waveguides is FALSE?
    • A. 

      Very slight damage to the external surface of a waveguide can cause arcing.

    • B. 

      Their conductive material construction is easily dented.

    • C. 

      Effectiveness of waveguides is hindered by moisture.

    • D. 

      Waveguides can be destroyed by corrosion.


  • 10. 
    What two properties of a transmission line determine its characteristic impedance?
    • A. 

      Inductance and resistance.

    • B. 

      Inductance and capacitance.

    • C. 

      Resistance and capacitance.

    • D. 

      Length and type of shielding.


  • 11. 
    Using figure 1–10, determine the electrical length if the frequency is changed from 150 MHz to 250 MHz.
    • A. 

      8.33 meters.

    • B. 

      8.33 wavelengths.

    • C. 

      83.3 meters.

    • D. 

      83.3 wavelengths.


  • 12. 
    Which statement concerning line lengths is TRUE?
    • A. 

      Frequency and electrical length are inversely proportional.

    • B. 

      Frequency and physical length are directly proportional.

    • C. 

      With constant physical length, frequency and electrical length are directly related.

    • D. 

      With constant physical length, frequency and electrical length are inversely related.


  • 13. 
    A nonresonant transmission line is a line
    • A. 

      Having reflected waves.

    • B. 

      Having no reflected waves.

    • C. 

      With maximum voltage across its open termination.

    • D. 

      With maximum voltage across its shorted termination.


  • 14. 
    If a transmission line is terminated in an open, what will likely result?
    • A. 

      Signal loss would be negligible.

    • B. 

      There would be significant signal loss.

    • C. 

      Current would be at maximum at the termination.

    • D. 

      Voltage would be at minimum at the termination.


  • 15. 
    The concept that alternating current changes in magnitude and reverses its direction during each cycle is
    • A. 

      An unproven hypothesis.

    • B. 

      The definition of propagation.

    • C. 

      What makes radio transmission possible.

    • D. 

      What led to the discovery of direct current.


  • 16. 
    At what point do magnetic fields around a wire no longer have time to collapse completely between alternations?
    • A. 

      60 cycles per second (cps).

    • B. 

      120 cps.

    • C. 

      10,000 cps.

    • D. 

      15,000 cps.


  • 17. 
    Which basic field detaches from the antenna and travels through space at great distances?
    • A. 

      Radiation.

    • B. 

      Induction.

    • C. 

      Gravitational.

    • D. 

      Electromotive.


  • 18. 
    Areas in which no antenna radiation pattern passes through are called
    • A. 

      Nulls.

    • B. 

      Lobes.

    • C. 

      Free space.

    • D. 

      Nonresonant.


  • 19. 
    If the electric field component travels in a plane perpendicular to the Earth’s surface, the radio wave is considered to be polarized
    • A. 

      Magnetically.

    • B. 

      Horizontally.

    • C. 

      Circularly.

    • D. 

      Vertically.


  • 20. 
    The actual range of frequencies within the antenna’s bandwidth is called the
    • A. 

      Wavelength.

    • B. 

      Operating zone.

    • C. 

      Frequency range.

    • D. 

      Bandwidth range.


  • 21. 
    What measurement is used to determine whether an antenna is resonant at a particular frequency?
    • A. 

      Distortion.

    • B. 

      Standing wave ratio.

    • C. 

      Signal-to-noise ratio.

    • D. 

      Percent of modulation.


  • 22. 
    The ability of an antenna to both receive and transmit equally well is known as the antenna’s
    • A. 

      Bandwidth.

    • B. 

      Resonance.

    • C. 

      Reciprocity.

    • D. 

      Effectiveness.


  • 23. 
    The standard used to measure the radiating effectiveness (gain) of an antenna system is the
    • A. 

      Marconi antenna.

    • B. 

      Isotropic antenna.

    • C. 

      Hertz antenna.

    • D. 

      Whip antenna.


  • 24. 
    What does the overall effectiveness of an entire transmitting and receiving system depend largely upon?
    • A. 

      Impedance matching.

    • B. 

      Antenna distance.

    • C. 

      Antenna properties.

    • D. 

      Line characteristics.


  • 25. 
    Which antenna radiates radio energy equally well in all directions?
    • A. 

      Omni-directional.

    • B. 

      Uni-directional.

    • C. 

      Bi-directional.

    • D. 

      Directional.


  • 26. 
    Which antenna type is usually used on long-range, point-to-point communication where the concentrated radio energy is needed for circuit reliability?
    • A. 

      Omni-directional.

    • B. 

      Uni-directional.

    • C. 

      Bi-directional.

    • D. 

      Circular.


  • 27. 
    Ungrounded lengths of wire specifically designed to be either a half-wavelength or more than full wavelength long is called a
    • A. 

      Reflector.

    • B. 

      Hertz antenna.

    • C. 

      Marconi antenna.

    • D. 

      Vertical monopole.


  • 28. 
    A dipole or long-wire antenna is an example of a
    • A. 

      Whip antenna.

    • B. 

      Hertz antenna.

    • C. 

      Marconi antenna.

    • D. 

      Vertical monopole.


  • 29. 
    What type of directivity does the whip antenna provide?
    • A. 

      Bidirectional.

    • B. 

      Unidirectional.

    • C. 

      Omni-directional.

    • D. 

      Near vertical directional.


  • 30. 
    What is probably the worst antenna that can be used on sky-wave circuits?
    • A. 

      Whip.

    • B. 

      Dipole.

    • C. 

      Rhombic.

    • D. 

      Discone.


  • 31. 
    What antenna radiates or receives on many of its particular elements?
    • A. 

      Whip.

    • B. 

      Dipole.

    • C. 

      Discone.

    • D. 

      Log-periodic.


  • 32. 
    What is the minimum length for a long-wire antenna?
    • A. 

      One-quarter wavelength.

    • B. 

      One-half wavelength.

    • C. 

      One wavelength.

    • D. 

      Two wavelengths.


  • 33. 
    A long-wire’s takeoff angle depends on the antenna’s
    • A. 

      Length.

    • B. 

      Directivity.

    • C. 

      Front-to-back ratio.

    • D. 

      Standing wave ratio.


  • 34. 
    A common satellite antenna is the
    • A. 

      Whip.

    • B. 

      Discone.

    • C. 

      Parabolic.

    • D. 

      Long-wire.


  • 35. 
    A helical satellite antenna radiates a signal with what type of polarization?
    • A. 

      Horizontal.

    • B. 

      Vertical.

    • C. 

      Circular.

    • D. 

      Linear.


  • 36. 
    Which type of airborne antenna can be designed into any part of an aerospace vehicle’s surface, so that it does not upset its aerodynamic properties?
    • A. 

      Fixed blade.

    • B. 

      Conformal.

    • C. 

      Probe tip.

    • D. 

      Whip.


  • 37. 
    In selecting an antenna for a circuit, what is the first thing to consider?
    • A. 

      Type of propagation.

    • B. 

      Type of antenna.

    • C. 

      Distance of the communication.

    • D. 

      Operating frequency of the antenna.


  • 38. 
    In HF communications, by replacing the vertical antenna with a dipole antenna that’s a quarter wavelength off the ground, what are you able to get from your antenna transmission?
    • A. 

      Higher take-off angle.

    • B. 

      Increase efficiency.

    • C. 

      Better reciprocity.

    • D. 

      Twice the gain.


  • 39. 
    In siting a radio station, which foliage would have more of an adverse effect on radio wave propagation?
    • A. 

      Broadleaf trees.

    • B. 

      Evergreen trees.

    • C. 

      Swamp grass.

    • D. 

      Sagebrush.


  • 40. 
    What has the greatest effect on an antenna?
    • A. 

      The sun.

    • B. 

      The earth.

    • C. 

      The operator.

    • D. 

      The ionosphere.


  • 41. 
    Which environment would be considered the most challenging for an RF transmission systems technician to establish and operate a radio station from?
    • A. 

      Amazon.

    • B. 

      North Pole.

    • C. 

      Sahara Desert.

    • D. 

      Sierra Nevada Mountains.


  • 42. 
    Radio sets are left on 24-hours a day in a jungle environment to
    • A. 

      Combat fungus.

    • B. 

      Keep insects away.

    • C. 

      Prevent short circuits.

    • D. 

      Maintain frequency stability.


  • 43. 
    Which environment area will increase maintenance problems with dust and sand?
    • A. 

      Polar.

    • B. 

      Jungle.

    • C. 

      Desert.

    • D. 

      Mountainous.


  • 44. 
    In mountainous terrain, with a mountain between you and the distant end, which of these antennas is more effective?
    • A. 

      Whip.

    • B. 

      Dipole.

    • C. 

      Discone.

    • D. 

      Near-vertical incidence skywave.


  • 45. 
    Radio waves that travel near the earth’s surface are called
    • A. 

      Earth waves.

    • B. 

      Global waves.

    • C. 

      Ground waves.

    • D. 

      Terrestrial waves.


  • 46. 
    The earth’s conductivity is determined by the type of
    • A. 

      Air and moisture content in the propagation path.

    • B. 

      Antenna being used at the time of transmission.

    • C. 

      Soil and water in the propagation path.

    • D. 

      Soil and air in the propagation path.


  • 47. 
    Sky wave transmission is used for which type of communications?
    • A. 

      Long distance.

    • B. 

      Subterrestrial.

    • C. 

      Atmospheric.

    • D. 

      Line of sight.


  • 48. 
    The angle at which a radio wave enters the ionosphere is known as the
    • A. 

      Skip angle.

    • B. 

      Critical angle.

    • C. 

      Angle of entrance.

    • D. 

      Angle of incidence.


  • 49. 
    Radio waves that angled too low are
    • A. 

      Absorbed.

    • B. 

      Refracted.

    • C. 

      Returned to earth.

    • D. 

      Passed into space.


  • 50. 
    In HF communications, the lowest frequency that arrives at the distant receiver on 90 percent of the undisturbed days of the month is called the
    • A. 

      Maximum usable frequency.

    • B. 

      Lowest usable frequency.

    • C. 

      Operating frequency.

    • D. 

      Critical frequency.


  • 51. 
    Magneton splitting creates two waves called
    • A. 

      Direct and indirect.

    • B. 

      Ordinary and abnormal.

    • C. 

      In-phase and out-of-phase.

    • D. 

      Ordinary and extraordinary.


  • 52. 
    In dealing with sky/ground wave propagation, the area of silence where no signals are received is known as the
    • A. 

      Propagation distance.

    • B. 

      Skip distance.

    • C. 

      Dead zone.

    • D. 

      Skip zone.


  • 53. 
    How many regions make up the atmosphere?
    • A. 

      2

    • B. 

      3

    • C. 

      4

    • D. 

      5


  • 54. 
    Scientist call the ionosphere an extension of the
    • A. 

      Thermosphere.

    • B. 

      Stratosphere.

    • C. 

      Mesosphere.

    • D. 

      Exosphere.


  • 55. 
    What occurs when high-energy ultraviolet light waves from the sun enter the ionospheric region of the atmosphere and strike the gas atoms?
    • A. 

      Ionization.

    • B. 

      Modulation.

    • C. 

      Conductivity.

    • D. 

      Recombination.


  • 56. 
    Sunspots are disturbances
    • A. 

      In the sun’s atmosphere.

    • B. 

      On the sun’s surface.

    • C. 

      In the ionosphere.

    • D. 

      Beneath the sun’s surface.


  • 57. 
    Sunspots occur on an
    • A. 

      11-day cycle.

    • B. 

      11-week cycle.

    • C. 

      11-month cycle.

    • D. 

      11-year cycle.


  • 58. 
    What U.S. government agency divides the radio frequency spectrum into different bands?
    • A. 

      Federal Aviation Agency.

    • B. 

      American National Standard Institute.

    • C. 

      Federal Communications Commission.

    • D. 

      Institute of Electrical & Electronics Engineers, Inc.


  • 59. 
    Near-vertical-incidence sky wave operations are most effective when you’re using
    • A. 

      Lower high frequency (HF) range.

    • B. 

      Higher (HF) range.

    • C. 

      Medium HF range.

    • D. 

      Low takeoff antenna angles.


  • 60. 
    Which frequency band is most susceptible to jamming?
    • A. 

      Low frequency.

    • B. 

      Medium frequency.

    • C. 

      High frequency.

    • D. 

      Very high frequency.


  • 61. 
    What frequency bands does the MILSTAR satellite system uses?
    • A. 

      High frequency (HF) and ultra high frequency (UHF).

    • B. 

      Super high frequency (SHF) and extremely high frequency (EHF).

    • C. 

      Very high frequency (VHF) and SHF.

    • D. 

      VHF and UHF.


  • 62. 
    The main very high frequency/ultra high frequency communications emphasis is on
    • A. 

      Long range deployable communications.

    • B. 

      Short range fixed communications.

    • C. 

      Emergency communications.

    • D. 

      Air-ground communications.


  • 63. 
    What is the primary transmission path for frequencies in the super high/extremely high frequency range?
    • A. 

      Direct.

    • B. 

      Ground.

    • C. 

      Surface.

    • D. 

      Sky wave.


  • 64. 
    Super high/extremely high frequency range is limited to
    • A. 

      Scattering.

    • B. 

      Line-of-sight.

    • C. 

      Earth’s conductivity.

    • D. 

      Atmospheric absorption.


  • 65. 
    The refractive index of air depends on moisture,
    • A. 

      Atmospheric pressure, and temperature.

    • B. 

      Atmospheric pressure, and frequency.

    • C. 

      Receive signal level, and temperature.

    • D. 

      Receive signal level, and frequency.


  • 66. 
    When comparing the radio and optical horizons, which one is farther away and by what percent?
    • A. 

      Optical; 15.

    • B. 

      Radio; 15.

    • C. 

      Optical; 33.

    • D. 

      Radio; 33.


  • 67. 
    What permits communication in shadow regions behind obstacles?
    • A. 

      Reflection.

    • B. 

      Scattering.

    • C. 

      Refraction.

    • D. 

      Diffraction.


  • 68. 
    What frequency range will show little effect from precipitation?
    • A. 

      High frequency.

    • B. 

      Ultra-high frequency.

    • C. 

      Super-high frequency.

    • D. 

      Extremely-high frequency.


  • 69. 
    Line of sight radio waves that are guided through the air between two layers of the atmosphere are known as
    • A. 

      Channeling.

    • B. 

      Guiding.

    • C. 

      Ducting.

    • D. 

      Piping.


  • 70. 
    Examples of electronic protection includes all of the following EXCEPT
    • A. 

      Frequency agility in a radio.

    • B. 

      Communications intelligence.

    • C. 

      Electronic and material shielding for systems.

    • D. 

      Process to counter meaconing, interference, jamming, and intrusion.


  • 71. 
    Which electronic warfare component responds to taskings to search for, intercept, identify, and locate intentional and unintentional sources of radiated energy?
    • A. 

      Attack.

    • B. 

      Control.

    • C. 

      Support.

    • D. 

      Protection.


  • 72. 
    What is the first step in electronic warfare application?
    • A. 

      Denial.

    • B. 

      Detection.

    • C. 

      Deception.

    • D. 

      Disruption.


  • 73. 
    Name the process of unscrambling the encrypted information so that it is intelligible.
    • A. 

      Decryption.

    • B. 

      Encryption.

    • C. 

      Cryptography.

    • D. 

      Cryptanalysis.


  • 74. 
    How many selectable traffic key slots does the KG–84A have?
    • A. 

      1.

    • B. 

      2.

    • C. 

      4.

    • D. 

      8.


  • 75. 
    Which switch on the KY–57 VINSON zeroizes channels one through five?
    • A. 

      Fill.

    • B. 

      Mode.

    • C. 

      Power.

    • D. 

      Volume.


  • 76. 
    The common name for the method of changing the encryption keys over the radio channel in a two-way radio system is called
    • A. 

      Over-the-air-rekeying.

    • B. 

      Asymmetric.

    • C. 

      Symmetric.

    • D. 

      Off-line.


  • 77. 
    In frequency hopping operation, the interval at which each transmitter remains on a given frequency for a specific time is known as
    • A. 

      Dwell time.

    • B. 

      Hopping rate.

    • C. 

      Frequency offset.

    • D. 

      Transmitter velocity.


  • 78. 
    From what source does the RT–1523 SINCGARS radio’s control module obtain instructions during remote and local operation respectively?
    • A. 

      Keyboard interface and front panel.

    • B. 

      Remote I/O module and front panel.

    • C. 

      Keyboard interface and local I/O module.

    • D. 

      Remote I/O module and keyboard assembly.


  • 79. 
    Concerning HAVE QUICK II communications multiple word-of-day (MWOD), how long can each word-of-day (WOD) be used?
    • A. 

      Each is used until it is manually changed.

    • B. 

      For a total of three days.

    • C. 

      For 48 hours.

    • D. 

      For 24 hours.


  • 80. 
    Which statement is NOT a characteristic of the AN/GRC–171B(V)4 transceiver?
    • A. 

      It operates from 116 MHz to 149.975 MHz.

    • B. 

      It provides antijam communications in AM and FM.

    • C. 

      It contains both HAVE QUICK and HAVE QUICK II.

    • D. 

      It can communicate on any one of 7,000 available channels.


  • 81. 
    What identifies the output power of the AN/GRC–171B(V)4 transceiver?
    • A. 

      25 watts in both AM and FM.

    • B. 

      20 watts in AM and 50 watts in FM.

    • C. 

      20 watts in AM and 20 watts in FM.

    • D. 

      50 watts in narrowband and 25 watts in wideband.


  • 82. 
    What commonly referred link is the joint tactical information distribution system?
    • A. 

      4A.

    • B. 

      11.

    • C. 

      16.

    • D. 

      22.


  • 83. 
    Which multiple channel access method eliminates the requirement for a net control station in the joint tactical information distribution system?
    • A. 

      Code division.

    • B. 

      Time division.

    • C. 

      Space division.

    • D. 

      Frequency division.


  • 84. 
    What type of network radio does the Air Force use for close air support?
    • A. 

      Single channel ground and airborne radio system.

    • B. 

      Enhanced position location reporting system.

    • C. 

      Joint tactical information distribution system.

    • D. 

      Situation awareness data link.


  • 85. 
    The family of radios that are scaled for use in all domains, will function with programmable waveforms, and be based on a common core architecture is the
    • A. 

      Joint tactical information distribution system.

    • B. 

      Single channel ground and airborne radio.

    • C. 

      Multiband radio sets.

    • D. 

      Joint tactical radio.


  • 86. 
    How many programmable devices can the multi-band inter/intra team radio hold?
    • A. 

      3.

    • B. 

      5.

    • C. 

      7.

    • D. 

      10.


  • 87. 
    Which conventional land mobile radio device serves as the hub of a net?
    • A. 

      Portable.

    • B. 

      Mobile.

    • C. 

      Repeater.

    • D. 

      Base station.


  • 88. 
    How many talkgroups can a trunked mobile radio monitor at one time?
    • A. 

      1.

    • B. 

      2.

    • C. 

      3.

    • D. 

      All the talkgroups programmed into the radio.


  • 89. 
    Who has the ability to patch different talkgroups together?
    • A. 

      Control station.

    • B. 

      Dispatch console.

    • C. 

      Portable.

    • D. 

      Mobile.


  • 90. 
    What Air Force instruction (AFI) requires communications squadrons to maintain “installation warning systems”?
    • A. 

      AFI 10–2501.

    • B. 

      AFI 21–116.

    • C. 

      AFI 33–106.

    • D. 

      AFI 33–118.


  • 91. 
    What is a common problem with a mass alert system in a deployed environment?
    • A. 

      Low power out.

    • B. 

      Efficiency.

    • C. 

      Cleanliness.

    • D. 

      Reliability.


  • 92. 
    In the Whelen siren cabinet, what controls signal routing and power distribution of the system?
    • A. 

      The landline board.

    • B. 

      The control board.

    • C. 

      The motherboard.

    • D. 

      The radio board.


  • 93. 
    In the Whelen system, how many digits make up the dual tone multi frequency (DTMF) protocol.
    • A. 

      6.

    • B. 

      8.

    • C. 

      10.

    • D. 

      12.


  • 94. 
    In high frequency communications, your station’s self address is the address
    • A. 

      The user programmed into your system.

    • B. 

      It shares with other members.

    • C. 

      Of an unprogrammed station.

    • D. 

      Of other stations in the net.


  • 95. 
    What are the three part data handshake between calling and receiving stations?
    • A. 

      Call, response, and acknowledgement.

    • B. 

      Call, request, and acknowledgement.

    • C. 

      Sound, handshake, and response.

    • D. 

      Sound, call, and response.


  • 96. 
    Transmitting a signal on a particular frequency in order to determine that channel’s usability is referred to as
    • A. 

      Call.

    • B. 

      Sounding.

    • C. 

      Networking.

    • D. 

      Handshaking.


  • 97. 
    What is the maximum power of the AN/PRC–150 in FM mode?
    • A. 

      5 watts.

    • B. 

      10 watts.

    • C. 

      15 watts.

    • D. 

      20 watts.


  • 98. 
    What assembly on the AN/PRC–150 contains the keyboard and the liquid crystal display (LCD) that makes up the radio’s man-machine interface?
    • A. 

      Chassis assembly.

    • B. 

      Rear panel assembly.

    • C. 

      Keyboard display unit.

    • D. 

      Upper chassis assembly.


  • 99. 
    Where do the modulation and digital-to-analog conversion take place in the AN/PRC– 150?
    • A. 

      Signal processing and control module.

    • B. 

      INFOSEC printed wiring board.

    • C. 

      Antenna coupler assembly.

    • D. 

      Crypto assembly.


  • 100. 
    What is one of the simplest and most functional antennas in use?
    • A. 

      Quarter-wave vertical.

    • B. 

      Half-wave dipole.

    • C. 

      Inverted-V.

    • D. 

      GRA – 4.


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