Cdc 2A251 Comm/nav Volume 5

Front 1

1. (801) If a radar echo returns after 310 microseconds, how far away is the target?

Back 1

25 miles

Hint 1

310 ÷ 12.4 microseconds

Front 2

2. (801) In which radar system does the transmitter produce a signal that regularly changes over a known range of frequencies?

Back 2

Frequency-modulation

Front 3

3. (801) In a pulse-modulation radar system, the transmitter DOES NOT interfere with the receiver. This is possible because the transmitter ______.

Back 3

is turned off after each pulse

Front 4

4. (801) Which radar system is based on the Doppler principle?

Back 4

Frequency-shift

Front 5

5. (802) In a pulse-modulation radar system, a high pluse repetition frequency radar limits range by ____.

Back 5

shortening listening time

Front 6

6. (802) Which component in a pulse-modulation radar set supplies the voltages that operate the other radar components?

Back 6

Power supply

Front 7

7. (802) Which component in a pulse-modulation radar system controls the operation of the entire radar set?

Back 7

Synchronizer

Front 8

8. (802) Where does the radar transmitter in a pulse-modulation radar system send a small amount of energy for use as a time reference?

Back 8

Receiver

Front 9

9. (802) The minimum range of a pulse-modulation radar system is determined by the pulse __.

Back 9

duration

Front 10

10. (802) As the pulse duration of a radar system increases, what will happen to the systems minimum and maximum range?

Back 10

Minimum range will increase, maximum range will increase.

Front 11

12. (803) In a frequency-shift radar system, the Doppler principle makes it possible to instantaneously sense and measure ___.

Back 11

groundspeed and drift angle

Front 12

13. (803) In a frequency-shift radar system, what is the relationship between a transmitter/receiver (T/R) and an aircraft when the received frequency is lower than the transmitted frequency?

Back 12

The aircraft is flying away from the T/R.

Front 13

14. (804) If the operating frequency is 100 megahertz (MHz) with a wavelength of 3 meters, then the frequency determining wall of the waveguide would be __.

Back 13

2.1 meters

Front 14

11. (802) The maximum range of a pulse-modulation radar system primarily depends on what?

Back 14

Power output

Hint 14

I skipped it lol

Front 15

15. (804) The function of a dummy load in search and weather radar is to

___.

Back 15

simulate a resistive load

Front 16

16. (804) What component is used to couple radio frequency energy between the waveguide and test equipment?

Back 16

Directional coupler

Front 17

17. (805) What is triggered when the AS–653C Radar Antenna Reflector rotates through the aircraft lubber line?

Back 17

Heading marker circuit.

Hint 17

Lubber rhymes with "rubber" and rubbers go on the head.

Front 18

18. (805) Which component in the AN/APN–59 Radar System furnishes both pitch and roll drive signals to the antenna stabilization motors?

Back 18

AM–853B.(electronic control amplifier)

Hint 18

AM- antenna motors

Front 19

19. (805) What component in the AN/APN–59 Radar System provides stabilized pitch and roll reference data for control of antenna orientation, despite changes in aircraft attitude?

Back 19

CN–221A (Stabilization data generator)

Hint 19

CN- control of antenna

Front 20

20. (806) What is the maximum height that the combined altitude radar altimeter subsystem computes aircraft altitude above ground level?

Back 20

50,000 feet.

Front 21

21. (806) When power is applied to the combined altitude radar altimeter, what is shown on the digital display?

Back 21

All dashes.

Front 22

22. (806) What is/are the function(s) of the SET knob located on the combined altitude radar altimeter indicator?

Back 22

Used as an on/off control, to set the VALI indicator, and as a test button to check the system.

Front 23

23. (806) What is the maximum altitude that the analog pointer and dial of the combined altitude radar altimeter can display?

Back 23

5,000 feet.

Hint 23

Analog

Front 24

24. (807) Which radar application is used to produce a pictorial map of the terrain?

Back 24

Ground mapping.

Front 25

25. (807) Which radar application is used primarily as an aid to navigation?

Back 25

Search radar.

Front 26

26. (807) Which radar application is used to fly along a preselected altitude above the ground?

Back 26

Terrain following.

Front 27

27. (807) Which radar application sends data to compute time-to-go parameters?

Back 27

Bombing radar.

Front 28

28. (808) What establishes the network system time for a Link–16 system?

Back 28

Network time reference.

Front 29

29. (808) How many hops per second does a Tactical Digital Information Link (TADIL) J perform to preclude jamming by a narrow band jammer?

Back 29

77,000 per second.

Hint 29

(per second)

Front 30

30. (808) When a Link–16 operator initiates the system using net number 127, then it indicates the use of a __.

Back 30

stacked net

Front 31

31. (809) To enhance voice clarity on Tactical Digital Information Link (TADIL) J secure digitized voice channels, the operator will select which data rate?

Back 31

16 kilobits.

Front 32

32. (810) What is the maximum number of Joint Tactical Information Distribution System (JTIDS) units (JU) that can participate in a Link–16 net?

Back 32

32,766 JUs.

Front 33

33. (810) To receive a track quality value of 15, how close must the track be to the reported position?

Back 33

50 feet.

Front 34

34. (810) Which of the following fields does the Link–16 friendly status reports contain?

Back 34

Equipment status.

Front 35

35. (810) What does the relative navigation (RELNAV) function of the Link–16 system determine?

Back 35

Distance.

Front 36

36. (811) The elapsed time indicator of the receiver/transmitter (R/T) indicates time power has been ___.

Back 36

applied to the R/T

Front 37

37. (811) Which subassembly is a part of the control monitor set (CMS)?

Back 37

SDU load control unit.

Front 38

38. (811) When transmitting in the high power mode, what is the power output of the high power amplifier of the Joint Tactical Information Distribution System (JTIDS) system?

Back 38

1050 watts

Hint 38

(high power mode)

Front 39

39. (812) What power source is used to provide emergency back-up power to the Joint Tactical Information Distribution System (JTIDS) terminal to maintain critical data?

Back 39

Nickel-cadmium batteries

Front 40

40. (812) What is the range of signals that the Low Pass Filters pass?

Back 40

960 – 1215 MHz

Front 41

41. (813) What is the operating band used by Joint Tactical Information Distribution System

Back 41

L-Band.

Front 42

42. (813) How many bits of data can be transmitted in a given time slot of a Joint Tactical Information Distribution System (JTIDS) system?

Back 42

930 bits.

Front 43

43. (813) Which time slot structure would you utilize if you wanted to reduce the silent period and eliminate redundant information every two pulses in the Joint Tactical Information Distribution System (JTIDS)?

Back 43

Packed–4 structure

Front 44

44. (814) When can the Joint Tactical Information Distribution System (JTIDS) synchronization process be initiated?

Back 44

Every 12 seconds when a Net Entry message is transmitted.

Front 45

45. (814) In coarse synchronization, how many receivers are used by the Joint Tactical Information Distribution System (JTIDS) receiver/transmitter?

Back 45

8.

Front 46

46. (814) What are the two processes in which Joint Tactical Information Distribution System (JTIDS) fine synchronization are accomplished?

Back 46

Passive and active.

Front 47

47. (815) Which component of the Tactical Information Gateway (TIG) system enables beyond line-of-sight (BLOS) coverage?

Back 47

Satellite communication/global positioning system antenna.

Front 48

48. (816) To prevent interference and possible terminal shutdowns, what systems does the Tactical Information Gateway (TIG) system monitor?

Back 48

IFF, ETCAS, and TACAN.

Front 49

49. (817) The serial transmission bit rate for the Military-Standard (MIL-STD) 1553 data bus is

Back 49

1 megabit per second.

Front 50

50. (817) What is the structure of a Military-Standard (MIL-STD) 1553 data word?

Back 50

20 bits long consisting of 3 sync bits, 16 data/command/status bits, and 1 parity bit.

Front 51

51. (817) In the Military-Standard (MIL-STD)1553 data bus system, if the bus controller (BC) does not require the data for processing, then what type of command is being used?

Back 51

RT to RT

Front 52

52. (817) Which of these is not a function of the Military-Standard (MIL-STD) 1553 data bus mode codes?

Back 52

Executing a bus controller (BC) broadcast command.

Front 53

53. (817) Which Military-Standard (MIL-STD) 1553 data bus version does not provide definitions for mode codes?

Back 53

MIL-STD 1553A

Front 54

54. (817) If a bus controller (BC) sends a command for all remote terminals (RT) to listen to data from another RT, then what type of command is being sent on the Military-Standard (MIL-STD) 1553 data bus?

Back 54

Broadcast command.

Front 55

55. (818) What is the primary unit of any computer information system?

Back 55

Central processing unit.

Front 56

56. (818) The basic element in a computer microchip is __.

Back 56

silicon

Front 57

57. (818) Chips with circuits that can do the work of all the different parts of a computer are called what?

Back 57

Microprocessors.

Front 58

58. (818) If the computer is receiving a binary code digit of 1, then that represents a what?

Back 58

Pulse.

Front 59

59. (818) What part of a computer acts like a sophisticated switchboard operator?

Back 59

Control unit.

Front 60

60. (819) The primary computer memory that usually cannot be erased is called?

Back 60

Read only memory (ROM).

Front 61

61. (819) Random access memory (RAM) is used to __.

Back 61

store information being calculated by the computer.

Front 62

62. (820) What keeps the computer monitor’s electron beams from spilling over into the wrong phosphors and improperly mixing colors?

Back 62

Shadow mask.

Front 63

63. (820) The resolution of a computer monitor is expressed in the number of pixels that make up the image. The sharper the image, the ___.

Back 63

higher the resolution

Front 64

64. (820) A video graphics array (VGA) computer monitor has how many pixels per horizontal line?

Back 64

640.

Front 65

65. (821) The main function of switches within a network is to ___.

Back 65

enable several users to send information over a network

Front 66

66. (822) The technique where blocks of data can be segmented into numerous blocks so sequential blocks can be written is __.

Back 66

data striping

Front 67

67. (822) Which redundant array of independent disks (RAID) parity is distributed across all drives and eliminates a bottleneck?

Back 67

RAID–5.

Front 68

68. (823) If you are checking for absolute power, then the power meter can be switched to displays in either watts or __.

Back 68

dBm

Front 69

69. (823) What power meter control compensates for a slight sensitivity associated with a particular type of power sensor?

Back 69

CAL ADJ.

Front 70

70. (823) When calibrating the power sensor you adjust the CAL ADJ control so that the digital readout indicates __.

Back 70

1.000 mW

Front 71

71. (823) Before turning on the power meter, you must make sure it is ___.

Back 71

set to match the line voltage you’re using

Front 72

72. (824) Horizontal deflection on the cathode-ray tube (CRT) on the time domain reflectometer (TDR) equates to what?

Back 72

Distance.

Front 73

73. (824) A time domain reflectometer (TDR) display that starts in the upper left corner of the screen, drops down at mid screen, and departs in the lower right screen indicates a what

Back 73

A short.

Front 74

74. (825) The radio frequency transmission line test set (RFTLTS) is used to diagnose cable faults through voltage standing wave ratio (VSWR)/return loss measurements and ___.

Back 74

distance-to-fault measurements

Front 75

75. (825) Which key of a radio frequency transmission line test set (RFTLTS) would you use to access the alpha portion of the alphanumeric key?

Back 75

SELECT.

Front 76

76. (825) What measurements are performed with the radio frequency transmission line test set (RFTLTS) when a fault is suspected in a RF transmission path because of unacceptable insertion loss?

Back 76

Distance-to-fault measurements.

Front 77

77. (825) Before power is connected to the radio frequency transmission line test set (RFTLTS) you must ensure the ON/POWER/OFF switch is in the OFF position and a suitable grounding strap is connected between the grounding lug on the right side of RFTLTS unit 1 and the __.

Back 77

aircraft

Front 78

78. (825) Which unit of the radio frequency transmission line test set (RFTLTS) is the accessory kit?

Back 78

2

Front 79

79. (826) To avoid measurement errors due to electromagnetic forces, the Model 4328A Milliohmmeter utilizes a what?

Back 79

0.1- kilohertz (kHz) signal.

Front 80

80. (826) The Model 4328A Milliohmmeter can maintain continuous battery operation for up to a total of __.

Back 80

8 hours

Front 81

81. (826) To set the Model 4328A Milliohmeter to mechanical zero, you must rotate the ___.

Back 81

METER adjust screw with the meter turned OFF

Front 82

82. (826) When using the 1 and 3 milliohm (mΩ) range on the Model 4328A Millohmmeter, the probes and cables should be perpendicular from the conductor face or place how far away from the conducting surface?

Back 82

10 centimeters (cm)

Front 83

83. (827) If 2 pounds of force is applied to the handle end of a 5-inch wrench, how much torque has been developed at the bolt end of the wrench?

Back 83

10-inch-pounds.

Hint 83

F x D = T

Front 84

84. (827) Which torque wrench uses micrometer-like markings and a rotating adjustment sleeve to set torque values?

Back 84

Type III.

Front 85

85. (827) The purpose of a balanced torquing sequence is to ___.

Back 85

prevent warping in the assembly

Front 86

86. (827) If you are going to torque a self –locking nut to 50–70 inch-pounds and the tech order states that the prevailing torque is at 30 inch-pounds, then the desired torque reading should ___.

Back 86

be compensated to read 80–100 inch-pounds

Hint 86

If the prevailing torque is more than one-third of the recommended torque, add it to the recommended torque and tighten the nut to this new torque value.

Front 87

87. (827) If you are going to torque a bolt to 60 inch-pounds and your wrench is 12 inches but you need to use an 8 inch extension, then what should your torque wrench be set at to compensate for the extension and reach the correct torque?

Back 87

36 inch-pounds.

Hint 87

S = (L / L+A) x T

Front 88

88. (827) Before using a dropped torque wrench, you must?

Back 88

Have it recalibrated.

Front 89

89. (828) The keyboard assembly of the SBA–100F bus analyzer consists of a ___.

Back 89

standard QWERTY format and a 18 key HEX format

Front 90

90. (829) Sealants keep out water, fumes and the atmosphere to protect the airframe against what?

Back 90

Corrosion.

Front 91

91. (829) The main purpose of a waveguide gasket is to prevent leakage of what?

Back 91

Energy.

Front 92

92. (830) The gain of which APX–64 Transponder Receiver/Transmitter module is increased when the confidence test is performed?

Back 92

Intermediate frequency (IF) amplifier.

Front 93

93. (830) The operating modes of the TS–1843A Transponder test set are what?

Back 93

TEST and MONITOR.

Front 94

94. (830) How many C-size batteries are required to replace the battery stick in the transponder TS–3977 test set?

Back 94

6.

Front 95

95. (830) When you press the TEST SEQ button on the transponder TS–3977 test set, the display will be visible for a maximum of __.

Back 95

3 seconds

Front 96

96. (830) When the TS–3977 test set battery voltage is low, ___.

Back 96

six of the decimal points are flashing on and off

Front 97

97. (831) Which Tactical Air Navigation (TACAN) checks should not be performed when using the ARM–184 flightline test set connected as a radiating transponder?

Back 97

Transmitter power and receiver sensitivity.

Front 98

98. (831) If you turn the BEARING CW/CCW switch on the ARM–184 flightline test set, then the indicator should increase or decrease at an angular rate of what?

Back 98

5° per second.

Front 99

99. (832) If the ARM–186 Very-High Frequency Omnirange/Instrument Landing System (VOR/ILS) ramp test set AMBER power indicator is on, how much operation time remains on the battery charge?

Back 99

0 to 1 hour.

Front 100

100. (832) The ARM–186 Very-High Frequency Omnirange/Instrument Landing System (VOR/ILS) test set provides radio frequency (RF) attenuation for signals over a 110-dB (decibels) range in what increments?

Back 100

1 dB.