various ct level questions Flashcards Preview

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Flashcards in various ct level questions Deck (119):
1

Two causes for an aerial lift to cease functioning while aloft

Hydraulic lift malfunctionInoperable upper controls

2

Three aerial lift operational hazards

ElectrocutionInjuries from falling, equipment failure, and unstable maneuveringTraffic lanes

3

Describe how the commtech's role may contribute to a successful preventative maint. program?

Respond quickly and efficiently to restore serviceperform work without degrading or interrupting serviceWork toward preventative maint. rather than repair

4

Three main causes of aerial lift accidents?

stability problemsoperator errorviolating OSHA regulations

5

How often are vehicle maint. checks completed?

Daily, weekly, monthly, bi-monthly, and semi-annually

6

Once completed the FCC form 320 is kept in?

The public file

7

Output C/N improves by _____ for each dB the input is raised?

1dB

8

What are two fiber splicing methods?

FusionMechanical

9

Hum modulation is measured in?

Percentages

10

Why is 16 QAM a faster modulation technique than QPSK?

Four amplitude levels are used.(2 above and 2 below each axis)

11

What is considered to be a 'headend' FCC POP test?

Differential Gain Differential Phase

12

T or F The video carrier under test must be on for the CTB measurement?

False

13

What do you test prior to operating from the aerial lift bucket

Always test the lift controls from the ground daily and verify that all are operating properly

14

7 Touchstones

DiversityRespectQualityEthicsEnthusiasmEmployee FocusFlexibility

15

What is an advantage that rebuilding a system has over an upgrade

Rebuilding increases the useable bandwidth

16

A reflection with the same polarity as the launch reflection indicates a(n)?

Open

17

What is Comcasts goal for network reliability?

4 nines / 99.99%

18

ICFR must be measured through a _______

Set-top-box

19

The _______ is the load-bearing component of an aerial hardline cable installation

Strand

20

What is meant by single mode?

One wavelength

21

Batteries should be within ____ VDC of each other

.3VDC

22

Which architecture offers the highest level of reliability?

Ring

23

Maximum length of data carrying CAT5

328' or 100 meters

24

Three parts of fiber

Core CladdingCoating

25

Three criteria for positioning your aerial lift

Minimize reachAvoid overhead obstaclesProvide safe and proper lift rotation

26

What material is used for doping fiber amps in the 1550nm band?

Erbium

27

When a loss of AC is determined to be a power company problem you should?

Contact the power company and follow your systems stand-by generator procedures

28

Deactivate anonymous call rejection

*87

29

Refractive index

Ratio of the velocity of light of two mediums of optical glass

30

Port-to-port isolation

The difference between the two output ports with the input port terminated

31

What is the cut-off freq. for a sub-split diplex filter at/around

50 Mhz

32

A cable with a single strength member in the center surrounded by the color coded buffer tube is known as?

Loose tube

33

Number of cycles of an AC waveform that occur in one second?

Frequency

34

What type of guy is used when strand changes direction?

Side Guy

35

What causes beats?

Unwanted carriers entering the systemCo-channelAmp levels running several dB higher than specified

36

How much time should be added to the 3-4 second rule when towing a trailer?

2 seconds

37

What is the maximum variation within a 24hr adjacent channel interval?

3dB

38

When performing a proof-of-performance, what is the maximum variation within a 6mo interval?

8dB

39

Initiate call trace

*57

40

How many times must the 24hr level variation test be performed?

4

41

Why didn't the skeleton cross the road?

He didn't have the guts!

42

Calculation for Wavelength?

Freq / speed of light

43

Laser Classes

ANSI Standard Z-136Class 1: Safe as long as not disassembledClass 2/2A: Eye hazard if beam is viewedClass 3A: Eye hazard if collected or focused on the eyeClass 3B: Eye hazard if the direct or reflected beam is viewedClass 4: Eye and skin hazard

44

What is the OTDR "dead zone" and how do you overcome its effect?

The length of fiber nearest the OTDR that is affected by the recovery of the receiver from the laser test pulse.Overcome by using a "launch fiber" sometimes called a "pulse suppressor"

45

4 types of AC waveforms?

Sine SquareQuasi-squareSawtooth

46

A reliability of "five nines" would allow how much downtime per year?

5.24 mins.

47

What is required to safely operate your aerial lift vehicle at the work site?

Properly using decalsUnderstand operational hazardsUtilize proper traffic controls techniques and safety equipment

48

Laser commonly used for downstream laser transmitters?

(DFB) Distributive Feedback

49

Hazards involved in parking an aerial lift on a slope

Reduced stabilityPlaces additional stress on the rotation systemRequires extra precaution to avoid overturning the vehicle

50

What doe s a spectrum analyzer do?

Continually scans the spectrum and has 'zoom' functionality

51

The effect that causes the optical signal to remain within the core of the optical fiber is called?

total internal reflection

52

What PPE should always be worn while working in your bucket?

Hardhat, gloves, safety boots, and eye protection

53

What situations require aerial rescue of an aerial lift operator?

Mechanical failureOperator falling out of the bucketUpper controls becoming inoperable

54

What component converts AC power to DC power needed to operate an amplifier?

DC power pack

55

Three protection methods used when working above 4ft on a tower?

Double lanyardFixed cable systemRetractable device

56

When does the 2-15ft rule apply?

when setting up a road side work zone 2ft from the curb or 15ft from the edge of the road

57

Amount of time it takes a waveform to complete 1 cycle?

Period

58

Goals of using proper traffic control techniques

Reduce accidents, minimize the chance of injury to employees and the public, reduce the chance of damage to private and public property, minimize the possibility of claims and litigation arising from work zone accidents, reducing confusion to motorists, expedite traffic flow, improve public image

59

What causes a stationary (or slightly moving)vertical bar in the video portion of a channel?

Cross Modulation

60

T or F a CLI flyover can be done at 450 meters?

True

61

How many phase angles are there in QAM?

4(0/360, 90, 180, and 270 degrees)

62

LASER

Light AmplificationStimulated byEmission ofRadiation

63

What is the function of the video bandwidth filter on a spectrum analyzer?

Takes the RF energy that has already passed through the RBW filter and the detector and smoothes it out

64

Nyquist's Rule?

C/N gets worse by 3dB each time the number of amps doubles.

65

Gated testing is ________

The ability to perform an intrusive test, non-intrusively.

66

How do you prevent accidental contact with electrical power?

Position your bucket lower than any power lines or components ie. transformers

67

Ratio of the velocity of light of two mediums of optical glass?

Refractive Index

68

What are the advantages of an HFC network?

Enhanced picture qualityIncreased reliabilityDecreased cost of system maint.

69

Components included in an aerial lift inspection

Bolts, welds, hydraulic oil level, hydraulic oil lines, loose objects on the boom and in the bucket, lower and upper controls, leveling system, decals, and bucket.

70

Minimum Clearance Requirements

300V or less: Avoid Contactover 300V under 750V: 12 inchesover 750V under 2 KV: 18 inchesover 2 KV under 15 KV: 24 inchesover 15 KV under 37 KV: 36 inchesover 37 KV under 87.5 KV: 42 inches

71

Types of decals

Danger WarningCautionOperating Instructions / Notice

72

Which fiber is considered to be the first fiber in the bundle?

Blue fiber, blue tube

73

What is the purpose of an EQ in a CATV amplifier?

It compensates for cable loss

74

When are aerial lift inspections conducted

Daily WeeklyMonthly

75

Ohms law for voltage?

E=IxR

76

1 complete sine wave?

Cycle

77

What are the different fiber connectors?

FC: ferruled connectorSC: snap connectorAPC: angle polished connectorUPC: ultra polished connectorLCSC: Special optical fiber connector used in gigabit Ethernet devices

78

Loop resistance is equal to the sum of the resistance of its_______and_______?

Center conductorSheath

79

How do you stand in your bucket to avoid falling out?

Feet flat on the floor of the bucket

80

How do you raise and lower tools and equipment from the bucket?

Hand line

81

What do you evaluate before ascending in an aerial lift?

Evaluate the desired work position of your bucket

82

Ohms law for current?

I=E/R

83

T or F Hum Modulation must be checked on at least 2 channels?

False

84

What is the first priority in an emergency rescue operation where the operator is injured or incapacitated?

The safety of the personnel involved

85

Fiber work area

Flat smooth surfaceDark colorResistant to the chemicals you'll be using

86

In fiber what is the largest cause of attenuation?

Scattering

87

Three Federal aerial lift safety rules?

OSHAANSIDOT

88

To prevent stress on the fiber, cable manufacturers put about 1% more fiber in the cable then the length of the cable itself to allow for some "stretch". This is called?

Lay loss factor

89

If you detect a leak coming from a customers house you must?

Notify the customer and arrange for access so that repairs can be made

90

What must you do prior to working aloft in your bucket?

always put on an approved fall arrest system (five point harness and deceleration lanyard)

91

Three aerial lift limits

Boom lift capacityBucket load capacityChassis weight

92

T or F CLI measurements are included in the FCC POP tests

False

93

What is the first thing you should do after an accident?

Protect / Secure the scene

94

The 24hr level variation tests must be performed at what intervals?

5-7 hours apart

95

Activate speed dial 8?

*74

96

Low cost narrow bandwidth laser used in the return path of two-way networks?

Fabry-Perot

97

What are the two common wavelengths used for optical fiber?

1310nm1550nm

98

Two main risks associated with operating an aerial lift?

electrocution injuries caused by falling

99

How often are FCC proof of performance tests performed?

Twice a year

100

How many test channels are needed for a 700Mhz system proof-of-performance?

10

101

DOCSIS

DataOverCableServiceInterfaceSpecification

102

Ingress?

Undesired signals entering the cable plant

103

For every dB the levels of an amplifier are raised, the carrier to Xmod ratio gets________?

2dB worse

104

How do you secure / optimize the stability of your aerial lift vehicle?

Maintain proper tire pressurePosition the vehicle near the work siteFace the vehicle up or down slopeHead the boom uphill and maintain the boom beyond the center of the vehicleUse outrigger padsDo not exceed a 5deg slope

105

Star code for last number dialed?

*69

106

What "absolute measurement" do you make with a power meter?

optical power

107

Three areas of lift inspections

truckboombucket

108

The FCC form used to monitor CLI performance is?

FCC form 320

109

A leak between 54-216 Mhz must not exceed

20umv at 3 meters

110

When using a TDR to find a fault you should?

Test the cable from both ends and cut the overlapping portion in half

111

Formula for C/N

C/N=L1-(NF-59.2)

112

The FCCs concern with CATV signal leakage is due to?

Interference with navigational and communications equipment

113

Methods used to perform CLI tests are?

Fly overSystem ride out

114

Commtech work shirts should be made of what material?

100% cotton

115

Which pad value is typically used in return amplifiers?

Zero

116

Ohms law for resistance?

R=E/I

117

T or F it does not matter which fiber is spliced first when restoring a cut fiber during an outage?

False

118

What is "7" equal to in binary?

0111

119

What gas is produced when batteries are charging?

Hydrogen