Flashcards in numbers tech related Deck (93)

1

## According to the C/N rule, each time the number of amplifiers doubles, the C/N gets worse by how much?

### 3 dB

2

## Per FCC rules, signal leakage between 54 MHz and 216 MHz must not exceed what?

### 20 microvolts per meter at 3 meters

3

## What is the typical bandwidth for C-band service?

### 500 MHz

4

## What frequency range must a spectrum analyzer have in order to align satellite dishes?

### 950 MHz - 1450 MHz

5

## All drop splitters must have a minimum return bandwidth of?

### 5 MHz to 42 MHz

6

## What is the diameter, in microns, of a single mode fiber strand with the coating intact?

### 250 microns

7

## "Four Nines" or 99.99% reliability allows for how many downtime minutes per customer per year? +/- 1 min.

### 52.42

8

## What is the proper depth of modulation percentage of the properly balanced video carrier?

### 87.5

9

## What is the maximum length of a series-6 drop that can be used in an underground installation?

### 150 feet

10

## What is the maximum current output supported by the Vista 20P control panel?

### 600 mA

11

## What is the maximum length for a coax jumper used between a wall plate and the CPE?

### 6 feet

12

## When terminating an unused tap port, what must be included in the terminator?

### Internal 75-ohm resistor

13

## Per FCC rules, signal leakage between 54 Mhz and 216 Mhz must not exceed what?

### 20 microvolts per meter at 3 meters

14

## What is the reference temperature to determine thermal noise level delivered to any load impedance?

### 68 degrees Fahrenheit (293.15 degrees Kelvin)

15

## When making attachments to the strand, what is the minimum distance from the center of the pole that the attachment can be made?

### 30 inches

16

## What is the minimum cable bend radius for series 6?

### 2.5 inch radius

17

## What CLI figure of merit must be met in order to comply with Federal Communications Commission Standards?

18

## For each dB increase in input optical power (dBm), the RF output increases by how many dBmV?

### 2 dBmV

19

## How much bandwidth is required when both video and audio broadcasts are sent via a satellite in analog format?

### 36 MHz

20

## What is 1 per million as expressed in scientific notation?

### 1.0E-6

21

## What is 1 millivolt equal to across a 75 ohm load?

### 0 dBmV

22

## What is the typical 1550nm fiber loss in dB/km?

### 0.25(+/-.1dB)

23

## When purchasing a fractional PRI, what is the minimum number of channels required per account?

### 6

24

## What is the total bandwidth, to the nearest thousandth, required for a single 24-channel PRI circuit?

### 1.544 Mbps

25

## What resistance is present in a circuit where 1 ampere of current dissipates 1 watt of power?

### 1 ohm

26

## What is the FCC signal leakage limit for frequencies below 54 MHz and above 216 MHz?

### 15 microvolts/meter at 30 meters (100 feet)

27

## What frequency does Comcast use for the MoCA channel?

### 1,150 MHz or 1.15 GHz

28

## What is the minimum PHY rate required between the Media Hub and the terminal?

### 180 Mbps

29

## When is the use of Series-11 or QR-320 permissible for an aerial drop?

### Greater than 150 feet or in situations where it will improve signal levels to within acceptable ranges

30

## What is the acceptable minimum tightening force for the connector on the port of a splitter?

### 20 inch lbs.

31

## What is the value for Boltzmann's Constant?

### 1.38x10E-23

32

## What is the maximum number of lines supported by a Polycom 335?

### 2

33

## What size ground wire is used with series-11 and QR320 cables?

### #10BRIS 7.1.7

34

## How many splices are permitted in an underground drop restoration with a cable longer than 60 feet which does NOT cross a driveway?

### 2

35

## To reduce the possibility of bleeding, carrier power levels of adjacent channels should be kept within what distance of each other?

### Within 2 dB of each other

36

## In a typical off-hook state, what is the level of tip wire voltage?

### -20VDC

37

## Which log value is used to calculate carrier to noise?

### 10

38

## If the input level (in dBmV) numerically equals an amplifier's noise figure, what will the output C/N be?

### 59.2 dB (+/- .5dB)

39

## At 64 Kbps, what is the sample rate per second in the G711PCM encoding scheme?

### 8,000 per second

40

## What is the forward bandwidth that must be supported by all active and passive equipment?

### 54 MHz to 1,002 MHz (1GHz)

41

## Which size bonding wires must be accommodated by the bonding wire attachment?

### #6 AWG to #14 AWG solid copper

42

## When installing an outlet, what is the standard height, in inches, from the floor to the bottom of the wall plate?

### 14 inches (or the same height as existing outlets)

43

## What is the number designation for a violet colored fiber optic cable?

### 10

44

## When bonding to a cold water pipe at the customer premise, what is the maximum distance the bond block can be from where the metal water pipe enters the home?

### 5 feet

45

## What is the distance a mechanical bender must remain in position until the lasher is transferred and the next span of cable is lashed?

### 50 feet or 1/3 the distance to the next pole

46

## What level of DC voltage would you expect to find at an amplifier DC test point?

### Between 24 and 28 VDC

47

## When testing batteries in a standby power supply, the difference in voltage levels should be no more than how many VDC?

### 0.3 VDC

48

## How many test points are required by the FCC for every 45,000 customers?

### 9

49

## For high resolution traces, how many sweep points may be entered for each 6MHz segment of bandwidth?

### Up to 3

50

## What is the minimum / maximum level of a leak that must be fixed within 72 hours?

### 20-149 uV/M

51

## What is the typical 1550 nm fiber loss in dB/Km?

### 0.25 (+/-.1dB)

52

## What is 1 millivolt equal to across a 75 ohm load? (dBmV)

### 0 dBmV

53

## What is the maximum number of devices that can be monitored from the Device Monitor tool in Watchtower?

### 3

54

## Which pad value is typically used in return amplifiers?

### 0

55

## A PRI trunk employs of how many D channels?

### 1

56

## What are the 2 output wavelengths of lasers?

### 1310mm and 1550mm

57

## What are the 2 most common optical wavelengths used by the CATV industry?

### 1310nm and 1550nm

58

## Which numbered pins are being used for transmit and receive when utilizing the RJ48C connection?

### 1, 2, 4 and 5

59

## When purchasing a fractional PRI, what is the minimum number of channels required per account?

### 6

60

## What is the visibility rating on a clear night for a road barrier's type B high intensity Warning Light?

### 1000 feet

61

## How much does signal attenuate on a 4-way splitter at 750 MHz?

### 8.1 dB

62

## How far should the center conductor project form the F-connector's edge?

### 1/16" to 1/8"

63

## What is the recommended modulator output in order to prevent overdriving the final amplifier stage?

### 90% of the maximum modulator output

64

## What is the transponder bandwidth that allows for the carriage of additional signals, such as additional audio and data communications?

### 40 MHz

65

## How much must a preamplifier increase the signal strength before feeding it to the power amplifier?

### 3 times

66

## What would be the maximum allowable sag in a 150' drop?

### 18 inches

67

## What is the output of a tap with an input of 23 dBmV and a value of 14?

### 9 dBmV

68

## Given voltage =10 and resistance =5, what would the current be?

### 2 amperes

69

## If a customer has 2 PRI, what is the maximum number of simultaneous calls they can have?

### 46

70

## What is the typical loss through a fusion splice?

### 0.1 dB

71

## What is the screen height of a 16:9 display measuring 42 inches diagonally?

### 21.6 inches

72

## What is the acceptable MER measurement on a 256 QAM at the tap?

### 35 dB

73

## How many inches does a strain relief loop drop when installing fiber optic cable?

### 2 to 4 inches / 5-10 cm

74

## What minimum distance should an aerial lift maintain from a power line that is between 800 volts and 750 volts?

### 12 inches

75

## During construction, what percentage of fiber cable is normally dedicated to "excess slack loops?"

### 5 percent

76

## If a span is ____ feet or longer, place _____ expansion loops on each pole.

### 250', 2

77

## Return amplifiers have this much gain?

### 20 dB

78

## What are the Aeronautical Frequency Bands?

### 108 to 137 MHz (Aeronautical Radio) and225 to 400 MHz (Aeronautical Navigation)

79

## At what altitude and frequency range is a flyover done at?

### 1500ft and 108 to 137 MHz

80

## What is the insertion loss of a diplex filter at 42Mhz?

### 1dB

81

## What are the Node DC Power pack voltages?

### 24 volts, 12 volts, and 5 volts

82

## What is a DC-20s insertion loss at 42MHz?

### 0.5 dB

83

## You will not see a ghost, whose level is more than _____dB below the desired carrier?

### 30 dB

84

## Carrier to beat ratios are greater than _____ are far enough below desired carrier levels to be of little concern to the average viewer?

### 57 dB

85

## In order for Co-channel interference to be visible, the difference in levels between the desired and undesired channels must be less than ____dB?

### 60 dB

86

## In CSO, the offending location is a group of beats located where?

### 1.25 MHz (+/- 15KHz) above the interfered channel's visual carrier

87

## Aeronautical radio communications bands operating frequencies are spaced at _____intervals, so cable carriers must be offset by _____?

### 25 KHz intervals, 12.5 KHz; +/-5KHz

88

## Aeronautical navigation carriers are spaced at ____ between carriers. For this reason, cable signals using this portion of the spectrum must be offset by _____?

### 50 KHz, 25 KHz; +/-5KHz

89

## Cable blocks should be placed on the strand every _____ to ______ ft?

### 30 ft to 50 ft

90

## Stop the lash about _____ feet from the pole?

### 6 ft

91

## What is the voltage for power over Ethernet?

### 48 VDC

92

## What is the maximum data throughput for a 64 QAM channel?

### 30.72 Mbps

93