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Flashcards in NCT4 Deck (413):
1

A frequency selective receiver capable of tuning in a desired frequency/Channel with a display showing RF signal strength (dBmV)

Signal Level Meter (SLM)

2

The minimum signal level at the input to the customers TV is

0dBmV to 15dBmV

3

what do you need to do to maintain an SLM

Keep the battery charged, clean the battery terminals regularly,keep the SLM clean by wiping it gently:dry the display screen to prevent spots, do not use any type of polish or cleaner on the display ,and a regular calibration should be made and logged,

4

The ratio of error power to average power in an ideal QAM signal is

MER

5

Average power =

Digital power

6

Peak Power=

Analog power

7

Optical power units

mW or dBm

8

RF power units

mV or dBmV

9

Attenuation/ gain units

dB

10

what mode monitors up to 12 chs at a time on your meter

Miniscan

11

what mode monitors the entire Ch plan on your meter

Full scan

12

what mode check s the forward low frequency and high frequency channel tilt

Tilt mode

13

Detects errored bits in the system

Bit error Rate (BER)

14

used for troubleshooting connections with intermittent bit errors occuring over a period of time

Errored Seconds

15

passage of an outside signal into the cable; can result in noise and disruption of the desired signal

Ingress

16

shows impairments on the networks with the patterns on display and can be identified by figuring out the patters

Constellation Graph

17

Displays intermittent short duration impairments missed by MER and BER on your meter.

Digital quality index (DQI) mode

18

this mode shows you if ingress is within the downstream digital spectrum without turning of service

QAM ingress mode

19

This mode greatly improves the success rate and efficiency in locating return-path ingress

Fieldview Option

20

Service quality depends on transmitting signals with the highest carrier to composite noise and the lowest intermodulation distortion. The majority of all transmission errors can be detected by measuring the frequency response of the network is

Sweep

21

Provides a quick method to check cable system integrity, using active channels to sweep the forward path is

Sweepless Sweep

22

Using a unique method to accurately reveal any problem in the system without interfering with any of the analog/ Digital carriers is

Forward Sweep

23

Helps find mismatches or other problems in the upstream transmission path

Reverse Sweep

24

Accurately measures Ac voltages of signals other than pure analog sine waves

Root Mean Square Meter (RMS)

25

This meter is used to measure AC and DC voltages and currents as well as resistance and has a digital display

Digital Multi meter (DMM)

26

is used to find the location/path of underground cables

Cable locator

27

has a transmitter and receiver. it could include the following components a test lead, inductive frame and A-frame.

A locator

28

The resistance of a circuit to alternating current.

Impedance

29

The condition that results when two components of a system are operating at different impedance

Impedance Mismatch

30

is used to determine the distance of a known fault from a specific location

Time Domain Reflectometer (TDR)

31

Is used to locate: bad or unknown splices, opens, shorts, and kinked cable.

TDR

32

A reflection with the same polarity indicates an

open

33

is a situation where the center conductor comes in contact with the shield

Dead Short

34

A reflection with the opposite polarity indicates that the fault is

Short

35

refer to a cable that has not been competely cut

Partial Open

36

The contact between the center conductor and the shield is not complete

Partial Short

37

The distance that cannot be seen by the TDR because its too close to the TDR source

Deadzone

38

two types of TDRs

Waveform and Digital

39

extremely thin flexible thread of pure cladded glass able to carry millions of times the information of a traditional copper wire and do it over greater distances

Optical Fiber

40

A device that generates a light source used in fiber communication

Laser

41

LASER

Light Amplification by Stimulated Emission Radiation

42

Most light generated by lasers for telecomm use exists in the infrared band of 1310nm and 1550nm wavelengths

Infrared Light

43

the distance between two points of like phase in a wave

Wavelength

44

A card made up of material similar to photographic film that changes colors when exposed to light

Photosensitive Card

45

Laser Classification

Class1-safe as long as they are not disassembled.; Class-2/2A Eye hazard if beam is viewed.;Class-3A Eye hazard if collected or focused on the eye.; Class3B Eye hazard if the direct or reflected beam is viewed.; Class4 eye and skin hazard.

46

what is the laser standard

ANSI Z-136

47

A method to lock and mark one end of a line in order to allow someone to safely work on the other end

Lockout Tag-out

48

what are the two methods of fiber cleaning

Wet and Dry

49

Materials needed for wet method

Lint free wipes, Isopropyl(better than 90%) as recommended by the manufacturer, and lint free swabs or urethane foam heads

50

rotate a cleaning cloth over the end of a fiber connector by pushing down toward the connector

Push Pen

51

A battery or generator that provides electrical power to the circuit. For example, batteries and generators

Power Source

52

A conductor such as copper wire

Path

53

the device that uses the electricity. it is any device that draws current

Load

54

Substance that allows heat or electricity to pass along or through it

Conductor

55

Subatomic particles found in atoms that balance out the positive charge of a proton with their negative charge

Electrons

56

is the electromotive force that causes electrons to flow in a circuit

Voltage (E)

57

The pressure that causes electrons to flow in a circuit

Electromotive Force

58

is the flow of electrons through a conductor. is measured in amperes and is designated mathematically in ohms law as the letter I

Current (I)

59

The amount of electrons that pass a given point in the conductor in one second

Coulomb

60

is the opposition a material offers offers to the flow of current

Resistance (R)

61

the difference in voltage between one point and another

Potential Difference

62

the direction of an electrical field in a radiated wave

Polarity

63

An electrical current of which the polarity is periodically reversed.

Alternating Current (AC)

64

the point at which the filament reaches a temperature that causes it to glow

incandescence

65

the relationship between current or voltage and elapsed time

AC Waveform

66

what are the 4 types of AC Waveforms

Sine Wave, Square Wave, Quasi-square wave, and Sawtooth Wave

67

this waveform represents the characteristics of the voltage/current that feeds homes, powers power supplies, and the television channels that carry the program information to your customers homes

Sine Wave

68

This waveform is often found within the switching regular DC output power supplies in Amplifiers

Square Wave

69

A CATV power supply without a load produces a near square wave that combines a non linear increase and decrease of voltage or current with extended maximum positive and negative peak value.

Quasi Square Wave

70

Types of signals carried on the HFC system

Modulated RF carriers, Modulated analog carriers, DC power and AC power

71

one complete sine wave is

Cycle

72

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

frequency

73

the speed of the light/Frequency=

Wavelength

74

the amount of time it takes a waveform to complete one cycle

Period(T)

75

peak value of a waveform

Amplitude

76

states that current is directly proportional to voltage and inversely proportional to resistance

Ohms Law

77

R=

The resistance in ohms

78

E=

the Electromotive force(EMF) in volts

79

the rate a which work is done or the rate at which energy is used

Power

80

I=

current in Amperes

81

Resistance is measured between the center conductor and sheath with the other end

DC Loop Resistance

82

P=

WAtts

83

Current at any point in the line in the HFC plant is equal to the sum of the individual Ampere current draws of the active devices being fed from that point.

AC Current in the Broadband Network

84

the amount of voltage loss over the span is referred to as

Voltage drop

85

At lower voltages the current is higher in the HFC plant

Current at lower voltages

86

the amount of energy available to move a certain number of electrons from one point to another in an electrical circuit

Voltage

87

to be subjected to the action of an electrical discharge

Shock

88

to kill by electrical shock

Electrocute

89

a connection to the earth or a grounding device

Ground

90

power supplies reduce the secondary power (120 or 240) to the 60 or 90VAC for insertion in the cable

Line power supply

91

the electricity provided by the local power company

commercial power

92

2 types of line power supplies

standby and non standby

93

reduction of voltage by a transformer

stepped down

94

conversion of voltage, in this case from 36 or 38VDC to 60 or 90VAC

Inverted

95

the point where AC power from the power supply is placed on the coax portion of the distribution network.

Power inserter

96

a filter that will only allow the higher RF frequency signals to pass directly from RF port to port

high pass filter (relating to power inserter)

97

a filter present on each leg to direct the flow of the lower frequency AC power, which prevents the RF Signal from traveling into the power supply and causing signal leakage

Low Pass filter(Relating to power Inserter)

98

the two types of network powering

Distributed and centralized powering

99

batteries produce what kind of gas during charging operations

Hydrogen

100

three methods for testing batteries

battery load test, battery voltage test, battery conductance test

101

the most accurate and reliable test involves testing the batteries under a load condition

Load Test

102

the difference between any batteries in the set should not be greater than

0.3VDC

103

measuring the impedance of the battery with a conductance meter and documenting that value when its new. Batteries less than 50% of their as new conductance values are known to be bad

Battery conductance test

104

means of testing the network remotely that saves numerous problems in respect to downtime and customer dissatisfaction

status monitoring

105

according to manufacturers the terminals should be torqued to_____and then retorqued to _____ during routine maintenance.

75inch lbs and 60 inch lbs

106

what points should be kept in mind while checking battery terminals

is there an in line fuse in the battery cable, check the fuse holder and fuse. make sure the terminals are properly greased with an approved corrosion inhibitor such as NCP-2 or NO-OX

107

the topology where signals originate in the headend and are transmitted long distances via trunk cables which have branches for directing the signal to customers

Tree and Branch

108

Forward signals originate at the headend are transmitted downstream by way of the trunk to the ends of the service.

Transportation (Trunk)

109

In a Tree and Branch system the feeder is considered what

The distribution System (Branches)

110

in a tree and branch system RG-6 and 11 is considered

The Drop(Leaves)

111

A network architecture developed by the cable industry which typically uses fiber optic cables to bring signals to selected areas of the system called Node Service Area, which are usually based on the number of subscribers to be served

Hybrid Fiber Coax(HFC)

112

what are the two wavelengths of fiber do we use

1310 nm and 1550nm

113

a network architecture where nodes, hubs, or headends may be connected with fiber optic cables to provide redundancy or increase services.

Ring

114

What are the advantages of fiber

Greater Bandwith and can travel greater distances without Amplification

115

what are the two types of Fiber

Single mode and Multi mode(we use single mode)

116

what is the attenuation of single mode fiber

1310nm=.35dB/km, 1550=.25dB/km

117

the distance between two points of like phase in a wave

wavelength

118

compares the speed of light through a material to the speed of light through a vacuum

Index of Refraction

119

the reflection that occurs when light strikes an interface at an angle of incidence greater than the critical angle allowing it to be continually reflected from the interface between two materials with different refractive indices

Total Internal Reflection

120

Single mode core is how many microns

8 to 9 microns

121

single mode cladding is how many microns

125 microns

122

single mode coating is how many microns

250 microns

123

what is the primary loss in fiber called

Scattering

124

separates(and recombines) the forward and reverse signals from the coax cable so they can be routed to and from the appropriate components within the amplifier station

Diplex filter

125

separates or combines the AC currents two parts-( AC power and RF broadband signals)

Power Diplex

126

attenuates the signal in order to bring it to within the acceptable range of the amplifier

Pad

127

compensates for the unequal attenuation properties of the coaxial cable. usually selected to produce flat broadband signals to the input of the first stage of Amplification

Equalizer

128

Usually selected for low noise figure. Amplifies forward signal passing through the trunk and distribution lines

Forward Amplifier Module (TRUNK)

129

Used to compensate for fluctuations of the input signal

AGC

130

Similiar to an AGC maintains the proper tilt(caused by temperature change in a specified amount of coaxial cable) and output level despite changes in the input signals

ALS

131

Signal splitting device that plugs into a trunk/bridger chassis

directional plug ins (feedermaker)

132

Converts AC power(60V-90V Quasi Square wave) to DC power(typically 24VDC)needed to operate the stations modules and regulates the DC output voltages to provide a stable and constant output

DC Power Pack

133

used to direct AC power into and out of specific ports of the amplifier station

Power Director

134

provides a means of monitoring the various inputs and outputs without interrupting service

Test Points (TP)

135

will have substantial isolation between the output and tap ports if all ports see a good 75 ohm match. Isolation for signal paths between the tap and output port is usually 25dB or greater

Directional Coupler (DC)

136

A tap is used to extract a specific amount of signal from the feeder system and distribute it for connection of customer drops and contains a directional coupler that feeds a single splitter.

Taps (Customer interface point)

137

Low frequency signals are not attenuated as much as high frequency signals in a coaxial cable

In line Equalizers

138

LIke in line EQs these devices are sometimes installed in the distribution cable where low value taps are used

in line conditioners

139

in a housing like the splitter is used to introduce AC power into the network

Power Inserter

140

A design philosophy where the loss of the cable and other passive devices before an amplifier station

Unity Gain

141

similar to a street map and includes features like lakes and rivers, streets, and boundaries

Base Map

142

Displays streets with poles and pedestals locations and includes the span length or footage between these items

Strand Map

143

Shows the locations of electronic equipment. including headend and any hubs,amplifiers, power, supplies, and taps.

Design Map

144

Offer the layout of the system in a condensed form. shows how active devices are cascaded and how they are connected to the headend, hub, or node. power supplies are also noted

Amplifier schematics or Tree Map

145

A corrected map that represent the addition or changes in information on the design map

As Built map

146

Map that covers a single node

HFC Plant map

147

documents a fiber plant

fiber design map

148

catalogs the system maps

Map Grid System

149

is the measure of the cables ability to maintain impedance at all frequencies due to the many micro reflections introduced during manufacturing. The industry Specs call for a minimum of 15dB, but the higher the better

Structural Return Loss (SRL)

150

What do reflections do on a coaxial cable

They distort the carriers, causing bit errors in the modulated data streams.

151

a thin wire wrapped around the fiber and coaxial cables to secure them to the strand

Lashing wire

152

load bearing component of an aerial coaxial cable installation. Its usually a 1/4 or3/8 inch zinc coated steel wire to which the cable is lashed

Strand

153

A loop intentionally formed in the cable to compensate for the expansion and contraction caused by temperature changes

Expansion Loop

154

used to counteract the horizontal component of forces placed on poles by the strand and cable

Guy and Anchor

155

Strand that connects the pole line hardware to anchor

Guy

156

Buried metal device used to transfer force from the pole to ground

Anchor

157

strand that connects the pole line hardware, particularly the guy attachment hardware to the anchor.

Guy Wires

158

is a yellow plastic cover used to protect the guy wire and make it more visible

Guy Wire Guard

159

Different types of Guys

Down Guy, Head Guy, Terminal Guy, Side Guy, Pole to stub guy, pole to pole guy, sidewalk guy, and storm guy

160

Different types of anchors

screw anchor, never creep anchor, rock anchor, anchor rods(AKA Guy rods)

161

the device usually a screw used to connect the coax's center conductor to an active or passive device

Seizure Mechanism

162

is used to remove the outer jacket of a typical underground cable

stripping tool

163

may remove the jacket, but primarily removes the outer sheath and dielectric within the cable

Coring Tool

164

having a saw toothed edge or margin notched with tooth like projections

Serrated

165

these tools are specifically designed to cut coaxial cables

banana cutters

166

what are the two steps in building the aerial portion of the network

the strand system must be built and properly tensioned and the cable must be lashed onto the strand.

167

to wrap a thin wire around the cable in order to secure it to the strand.

Lashed

168

this device is selectively placed at pole hardware locations to prevent dangerous sag while strand is being installed

Strand Brake

169

used in conjunction with a lay up stick to lift cable blocks and strand

Wire raising tool

170

used to prevent unwanted payoff of strand from the cable trailer or reel stand

Reel Brakes

171

are portable bonding connections installed at the location where the strand is spooled from the cable trailer or reel stand. can be removed only after the strand is bonded to the grounding network

Traveling grounds

172

two types of strand methods

Stationary reel method and Moving reel method

173

installation of pole hardware allowing for hanging of strand

Framed

174

the trailer should be at a minimal distance (two times the hardware attachment height) from the pole at which the strand first contacts the pole line hardware

Stationary reel method

175

the strand is installed by mounting a reel to a vehicle and driving the vehicle from pole to pole stopping to install the strand and hardware at each location

Moving reel method

176

Strand splices should be placed outside the pole framing hardware, but within 18 to 24 inches of the pole . traveling grounds should always be used when placing the strand

Stationary reel method

177

uses a mechanical wrenching action to bend expansion loops into coaxial cable prior to lashing or during splicing

Mechanical Bender

178

used to measure the pulling tension applied to cables

Dynamometer

179

allows cables that are being pulled to swivel and are used to ensure that the cables are not over-tensioned during pulling

Breakaway swivel

180

used to support a single lashing may be used when cables are lashed directly to the strand or in overlash applications

Single roller Block

181

used to install self support cable and is attached to the pole hardware support the cable as it is pulled out

Pole Mount Cable Block

182

used to support a single cable prior to lashing

Economy Block

183

This device is used to route cables through inside or outside corners up to 90degrees. it minimizes drag on the cable in corners and ensures that the minimum bend radius of the cable, as specified by the manufacturer is not exceeded

90 degree corner block

184

used to route cables through inside or outside corners up to 45degrees. it minimizes drag on the cable in corners and ensures that the minimum bend radius of the cable is not exceeded

45 degree corner block

185

used to guide cables from the cable trailer or reel strand to the strand

Set up Chute

186

this bracket is used to support 45 and 90 degree corner block or setup chutes at the mid span

set up bracket

187

used to lash cable directly to installed strand or cable bundles

cable lasher

188

allows multiple cables to be pulled into place when lashing cable directly to strand

Multiple cable puller

189

allows multiple cables to be pulled into place in overlash applications

Overlash cable puller

190

device is used to push equipment ahead of a pulled lasher

Cable block pusher

191

pushed in front of a lasher by a cable block pusher to uniformly position multiple cables that are being lashed

Cable positioner (Magic Box)

192

is the tension caused by the mass of cable on the reel and reel brakes.

tail loading

193

what two methods control tail loading

can be minimized by using minimal braking during the payoff of the cable from the reel. and at times no braking is preferred.

194

If a span is _____ or longer place ____ expansion loops on each pole. one is placed on the input side and one is placed on the output side of the pole

250ft and 2

195

is when two perpendicular strands end at the same pole

Double dead end

196

the mechanical bender must remain in place until the lasher is transferred and the next span of cable is

lashed 50ft or 1/3 the distance to the next pole whichever is greater

197

An expansion loop should be formed on the ___ side of every pole for all sizes of coaxial cable being used

Output

198

When the loop location is dictated by the signal flow direction of the feeder cable

Feeder Dominant

199

the trailer should be positioned in line with the strand and twice the distance _____

of the set up chute to the ground from the chute (Stationary Reel method)

200

The cable should payofff the___

Top of the cable reel

201

Use a cable block lifter to place _____ on the strand every 30 to 50ft

cable blocks

202

the ends of the cable left at the pole for splicing

Cable Tail

203

it is essential that double lashing be used when___

two or more cables, all trunk cables, and at street crossings.

204

how many feet do you stop the lasher to form an expansion loop

6FT

205

is a connection to earth or a conductor serving earth potential and can be intentional or accidental

Ground

206

is the interconnection through good conductors of the cable plant with power and phone systems to eliminate potential voltage differences

Bond

207

is a pipe usually made of PVC and used to house cable and protect it from dirt, moisture, and outside forces.

conduit

208

is a protective covering for hardline cable, typically made from galvanized steel or plastic over the exposed cable where it makes the transition from aerial to underground.

Riser Guard

209

conduit for underground drops must be buried to a minimum depth of

8inches

210

installing all underground drops emerging from the ground must have physical protection (cable guard or conduit) to a point at least ________located at the house

4ft above ground or until reaching the service enclosure.

211

underground drop cables routed down a pole must have physical protection, cable guard, or conduit, to at least

8ft above ground and at least 8inches below ground

212

a high visibility tape usually used when burying fiber optic cable, buried directly above the cable point out the existence of the cable to anyone digging in that location

Warning Tape

213

bury warning tape above the cable at a depth of___ during the back fill process

12inches

214

Locate the midpoint of the pull. while monitoring pulling tension, pull the cable from the mid point to the end of one direction.(Used for installing long fiber runs)

Mid point cable pull

215

what u do with the remaining fiber optic cable

figure eighting

216

while doing the figure eights with fiber u set the cones up ____ apart

10-15 paces

217

the US government agency established in 1934 to regulate electronic communications

Federal Communications Commission(FCC)

218

In 1990, the FCC required that system perform s CLI test ____

Annually

219

a figure of merit derived mathematically from the number and severity of signal leaks in a cable system.

Cumulative Leakage Index

220

the figure of merit for CLI has to be

64 or less

221

your CLI test that you do annually has to be submitted using what form

FCC form 320

222

a system in which transported signals are completely contained within the medium is called

a closed system

223

Leakage is emitted RF energy and is called

Egress

224

Noise is received energy and is called

Ingress

225

what % of leakage is found between the tap and bonding block

70%

226

LTE

Long Term Evolution

227

LTE operates in the ____frequency range

700 to800 MHz

228

No more than 15 microvolts per meter @30 meters

0-54MHz

229

No more than 15 microvolts per meter @30 meters

More than 216MHz

230

No more than 20 microvolts @3 meters

54MHz and 216MHz

231

the aeronautical frequencies are

108-137MHz

232

two ways to do the CLI test

Ground based and flyover

233

Leakage monitoring must be done

Quarterly

234

Leakage logs must be kept on file for

2yrs

235

Only Leakages___ or greater are included in the CLI calculations

50 microvolts

236

CW

continuous wave

237

three methods to calibrate your leakage detector

Done by the manufacturer, Direct coupling, and Antenna

238

what method do you use to pinpoint a leak

Triangulation Method

239

a leakage log should include

Date;location;leakage cause;strength;distance to leak; Date;Strength after repair.

240

leaks__ or greater must be logged for regular monitoring

20 microvolts

241

the FCC requires that __ of the plant be tested for CLI. The comcast standard is _____

75% and 100%

242

The CLI is done at an altitude of ____, using 108 to 137MHz band

1500ft(450Meters)

243

Sending AC from two different power supplies, causing a large spark

bucking power

244

Comcast troubleshooting steps

Identify, Isolate,Fix,Verify

245

a low resistance connection between two points in an electric circuit that forms an alternative path for a portion of the current

Shunts

246

Steps for verifying a backwards tap

1) the tap plate and re-check the input port. 2)if there is no signal present, check the output port. 3) if signal is present here, the housing is backwards and requires re-splicing.

247

if you encounter a conductor that is 300v or less

avoid contact with the conductor

248

if you encounter a conductor that is between 300V and 750V

stay at least 12 inches away from this conductor

249

do foreign voltage detectors DC voltage

NO

250

Divide and conquer does what

reduces repair time.

251

the reverse path must be balanced for___ just as the with the forward system

unity gain

252

threshold for ingress at 5-18mhz

-20dBc (Decibels relative to carrier)

253

threshold for ingress at 18-42mhz

-35dBc (Decibels relative to carrier)

254

Max min sweep formula

N/2+1.5=

255

telemetry reverse sweep formula

N/2+1=

256

is defined as two or more customers without service or with impaired service, due to the same root cause

outage

257

is a plant fault with overlapping correlated trouble call

priority plant fault

258

is a signals inability to be transmitted from one cable or device to another cable or device and measured in dB

Isolation

259

is the difference in dB, of a signal level, injected into one output port, and the measured level of the same signal on another output port with the input port properly terminated

port to port isolation

260

is the interface location in a cable system where a fiber enters a neighborhood and the optical signal is converted into an electrical signal to connect to coaxial cables serving individual homes.

Node

261

a node has a minimum of

One optical receiver, one optical transmitter, power supply, and a forward and return amplifier module

262

is an amplifier used to transport signals to longer distances

trunk amplifier

263

used to add to the strength of signals in order to compensate for higher loss of the feeder and to provide enough signals for the drop cables and for multiple customers

Bridger amplifiers

264

are high gain amplifiers and are operated so that the output levels are higher as well

Line extenders

265

samples the stations output level using the directional coupler 15 usually at a specific frequency or channel. used to compensate for fluctuations of the input

Automatic gain control

266

recovers the RF information modulated onto the optical carrier at the headend

Optical detector

267

refers to the percentage of optical modulation, per channel, driving a laser transmitter

Optical modulation Index(OMI)

268

for every db change in optical power there is a 2db change in RF

know that rule

269

to energize or power the equipment( nodes amplifiers and other active devices in the rf portion of the network). usually includes checks for continuity, shorts, and signal flow.

activation

270

whatever tilt u need multiply by 1.25 to get desired eq

know this rule

271

has attenuation that duplicates that of a cable.

Cable Equivalency (Cable simulator)

272

used for the first stage of amplification for a trunk or multi output station, picked for its low noise figure

integrated circuit (IC)

273

this device monitors the change in temperature and makes an attenuation and tilt change based on typical cable spacing between stations

thermal level control

274

this is usually a power double device

second stage gain

275

is used to compensate for frequency response signatures of passive and active devices in the system,

Response network/Mop up

276

circuitry used to adjust the frequency of an amplifier

response network

277

usually a passive network placed between the input and output amplifier module. it is used to correct fro a frequency response problem seen at the output of the amplifier

mop up

278

the deviation in response at the output of an amplifier or passive device when compared to the response st its input.

signatures

279

used to set the amplifiers output tilt.

interstage Equalizer

280

a measure of an amplifiers output level to the level of distortion it produces

output capability

281

is used to inject return test signals for alignment/sweep of the return portion of the amplifier

Insertion point

282

Reverse pad=amplifier upstream design gain-total span loss

know this rule

283

have forward and return on the same test point

bi directional test points

284

RF portion of the cable plant fed from a node

Node service area

285

we can utilize a 3% ____ without excessive distortion with a carriage of 100 channels

OMI

286

is the actual seep response before normalization

raw sweep

287

is the exponent or the power to which a fixed number(the base) must be raised in order to produce a given number

logarithm

288

the number of times the base is multiplied by itself

exponent

289

1)any number raised to the exponent 0 is equal to 1.2)any number raised to the exponent 1 is equal to itself. 3) two multiply two or more numbers with the same base, simply add the exponents. 4) to divide two or more numbers with the same base simply subtract the exponents.

Exponent rules

290

is a number where the base is 10

power of 10

291

one tenth of a bel=

Decibel

292

is the unit for expressing in logarithmic terms, the ratio between two power levels

Bel

293

with the 10 log function each double in value is equal to 3.01db increase, while -3.01 divides the value in half

know this rule

294

an absolute level that describes the amount of signal at a specific location in the system.

dBmV

295

10log=

wattage

296

20 log=

voltages

297

0dBmV=

1mV

298

each 6dB change either doubles or halves the voltage, and each 20dB change affects the voltage by a factor of ten

know this rule

299

a discontinuous signal whose various states are discrete intervals apart

digital signal

300

used to convert an analog signal to a digital signal

Digitizer

301

are a continuous signal or carrier that varies in amplitude or frequency

analog signals

302

this term is short for binary digit. refers to an electrical impulse representing a zero or a one. the smallest unit of measurement a computer can handle

bit

303

a set of bits that represent a single character. usually there are eight bits in a

Byte

304

the number of changed states that can occur per second

Baud

305

advantage of analog transmissions are

1) no conversion necessary for human recognition 2) economical over short distances (up to 25miles)

306

disadvantages of analog transmission are

1) added distortion and noise when employing amplification. 2) electrical interference modulating the waveform. 3) limited distance for acceptable performance.

307

digital conversion consists of

sampling, quantization, and encoding

308

is the measuring of the analog signal at specific intervals

Sampling

309

is the assigning of a specific value to each of the samples

Quantization

310

is the process by which these values are converted into a data or bit stream

Encoding

311

can interfere with an analog signal and reduce its clarity

thermal or interfering noise

312

is synchronized with that of the transmitter so its available to read the digital sample when it arrives

digital receiver or regenerator

313

are regenerated rather than amplified

Digital bits

314

is the means of superimposing sound on an RF carrier

AM

315

is the means of superimposing sound on an RF carrier of a particular frequency

FM

316

3 different types of modulation in analog

Amplitude(AM),Frequency(FM), and Phase(PM)

317

five most common modulation schemes are

1)Amplitude shift keying(ASK) 2) Frequency shift keying(FSK). 3) Phase shift keying(PSK). 4) Quadrature phase shift keying(QPSK). 5) Quadrature amplitude modulation(QAM)

318

frequency and phase of the signal carrier are constant. amplitude is varied

Amplitude shit keying(ASK)

319

amplitude and phase of the signal are constant. frequency is varied. used in pathrak telemetries

Frequency is varied (FSK)

320

amplitude and frequency are constant. phase is varied.

Phase shift keying (PSK)

321

defined as the position on a waveform cycle at a specific point in time. on cycle is defined as 360 degrees of phase

Phase

322

the two most common digital modulation schemes that use a combination of changes are

QPSK and QAM

323

unwanted sum of and difference in frequencies resulting from the heterodyning of two or more signals

Beat

324

are caused when an analog TV signal arrives at a receiver just before or after the desired TV signal

Ghost

325

caused when the same channel from two or more different TV stations is received by the same antenna

co channel interference

326

caused by power line arcing, lightning, electrical motors, automobile ignition, and other sources of high rise time energy entering the cable system from the tap up to and including the TV receiver

Electrical interference

327

ingress from transmitters operating in the upstream frequency bandwith

return path interference

328

often caused by poorly made or corroded connectors ,it actually changes the shape of the RF wave from(disimilar metals)

common path distortion (CPD)

329

what causes CPD

when two or more carries encounter a non linear device, such as a connection where oxidation has occurred, harmonics and difference are produced

330

a chemical change caused by a reaction to oxygen, such as rust

Oxidation

331

a component frequency of the signal that is an integer multiple of the fundamental frequency.(twice whatever original frequency is)

Harmonics

332

the amount of noise an amp adds

noise figure

333

is caused by random electron activity of the atoms that make up the conductor, resistor, or any part of the passive circuit in question at any temperature above absolute zero

thermal noise

334

a theoretical temperature equivalent to the absolute absence of heat and equal to -273.15 degrees C, -459.67F, or zero degrees Kelvin

absolute zero

335

change in termination noise amounts to approximately .17dB per 20 degree fahrenheit change in temperature

know this rule

336

C/N Rules

Rule 1) if the input level numerically equals an amplifiers NF, the output ratio will always be 59.2dB. Rule 2) for each dB when the input level is raised above the amplifiers NF, the output ratio improves by an equal amount above 59.2. Rule3) C/N ratio at the output of a single amplifier is always worse than that at the input an amount equal to the amplifiers NF

337

log uses

10logN for C/N, 12 logN for composite second order (CSO), and 20 logN for Xmod and CTB

338

undesired change in the waveform of a signal

distortions

339

the second harmonic products of any two channels are typically 6dB below the level of the sum and difference products

Discrete second order

340

the combination of the amplitude and the logarithmic sum of the number of beats that fall in a channel determine the level of interference

composite second order

341

when a carrier is applied to an amplifier, it will produce the second order beats and will produced third order products as well

discrete third order

342

as each carrier is added to the system , it interacts with all the other carriers producing more and more second and third order beats.

composite third order

343

C/CTB follows a 20log relationship, and each dB raise in the levels of an amplifier, the carrier to CTB gets worse by two dB

know this rule

344

adding two devices with the same C/CTB ratios degrades the result by 6dB

know this rule

345

the crossing of modulation from one channel to another. typically manifests itself as a vertical bar in the viewed picture

cross modulation(XMOD)

346

this is a third order product and follows a 20log function for every dB that the levels of an amplifier are raised the carrier to cross mod ratio gets 2db worse

know this rule

347

doubling the number of channels carried degrades this ratio by 6dB and so does doubling the cascade

know this rule

348

appears as horizontal bars in the picture . a primary source is the power passing chokes or capacitor leak in passive devices.

Hum modulation

349

amplifier circuit paths that allow AC voltage to be directed onto specific cables

Power passing chokes

350

hum modulation is a low frequency signal, which the FCC states must be less than 3% of the video carrier level

Hum modulation Test

351

are the two basic parameters used to evaluate the quality and performance of the digital signals

MER and BER

352

is defined as the ratio of the number of wrong bits over the number of total bits

Ber

353

is typically an overload effect noted through digital signal processing equipment. this is an overdrive, or over modulation of the single carrier

Spectral re growth

354

an international telecommunications standard that permits the addition of high speed data transfer to an existing CATV system

DOCSIS

355

generates light in the transmitter

Laser Diode

356

is a family of standards for compressing decompressing A/V in a digital format

MPEG

357

advantages of MPEG are

remove redundant info without losing quality while saving bandwith

358

MPEG1

video CD

359

MPEG2

HDTV/DVD

360

MPEG4

streaming video

361

has all the spatial info

I picture

362

use both past and subsequent pictures

B picture

363

is calculated by comparing previous and successive picture

P picture

364

a cable version of CDMA , a cell phone technology that allows many users to access the network at the same time

SCDMA

365

provides the ability to control latency

QOS

366

how many channels can u bond with docsis 3.0

4 or 8 down 4 up

367

number of timeouts caused by the cmts not receiving a response within aspecified time from the cmts to a ranging request. upstream errors

T3

368

number of timeouts caused by the modem not receiving a response within a specified time from the cmts to a periodic maintenance request. downstream errors

T4

369

the operational settings for the cable modem

Boot file

370

a series of Reed -Solomon symbols forms the codeword. it s a series of values that conforms to a known pattern.

codewords

371

when there are more than___ errored symbols in a codeword the entire codeword is errored

3

372

technologies that allow cable modems to share the upstream carriers in the hfc network with multiple devices like cable modems, emtas, and set top boxes

TDMA and SCDMA

373

method for transferring data across the network

Trivial file transfer protocol (TFTP)

374

assigns time slots for when modems can speak. configured in the CMTS

TDMA

375

instead of a time slot, the modem gets a code for all the data it is sending

SCDMA

376

is a set of rules that govern how devices transport data

Protocol

377

allows interoperability of devices from different vendors

protocols

378

is a way to tell the sending server that not all packets got to their destination, and please resend them.

Transmission control protocol/ internet protocol (TCP/IP)

379

used to transport voice and video media

Real Time Transport Protocol (RTP)

380

unlike tcp/ip it has no error correction

Universal Datagram Protocol (UDP)

381

UTP

unshielded twisted pair

382

has a field of 32 bits and dotted decimal

ipv4

383

written in colon hexidecimal format and uses numbers and letters

ipv6

384

can be configured for ipv4only or ipv6only

singlestacked device

385

can be configured fro both ipv4 or 6

dual stacked device

386

rules for writing ipv6 addresses

1) omit leading zeros, meaning zeros at the beginning of each set of four characters. 2) replace consecutive all zero chunks within an address by using a double colon

387

caused by off air ingress. (Direct pickup)

leading ghost

388

detects the light in the receiver and converts it to RF

Photo Diode (Photo Detector)

389

undesired light leaving the core

refraction

390

FCC requires us to offset frequencies when levels in the aeronuatical band are ____ or higher

38.75

391

what is the frequency offset for channels in the aeronautical communication band

12.5khz

392

when padding to the chip what are the combined internal losses (DC test point, EQ, Diplex filter)

3dB

393

CTB shows up where in the channel

within 30khz of the video carrier

394

CSO shows up where in the channel

plus or minus .75 and plus or minus 1.25mhz above or below the video carrier

395

harmonics are___ down from the sum/diff beats

6dB

396

what is the ch offset for channels in the aeronautical navigation frequency

25khz

397

the aeronautical navigation frequency carriers are spaced at ____ between carriers

50khz

398

what kind of split is in the diplex filter

sub split

399

shows the relationship between voltage or current and time

AC waveform

400

the position of a waveform at a specific point in time

phase

401

amplitude=

peak

402

changing or varying the amplitude, frequency, or phase

modulation

403

4 phases, constant amplitude, 2 bits per symbol

QPSK

404

multiple amplitudes, 4 phases, combo of QPSK and ASK

QAM

405

sample at twice the frequency that is being digitized

Nyquist rule

406

ADC

analog to digital conversion

407

DAC

Digital to analog conversion

408

how many pictures form a group of pics

12

409

GOP

group of pictures

410

provides output tilt

interstage EQ

411

a measure of an amplifiers output level compared to the amount of distortion its

output capability

412

the default telemetry frequencies for fwd sweep/rtn sweep and pathtrak

53=pathtrak, 51= forward, 52, return

413

a combo of ASK and QPSK

QAM