Installer Technician
Which of the following formulas is used to calculate normal attenuation of a certain length of coaxial drop cable?
(Cable length in feet/100)X Cable attenuation in decibels (per 100 feet) at frequency (f).
IT= _____________ amps in a DC series circuit where R1= 10 ohms, R2= 20 ohms, R3= 30 ohms, R4= 40 ohms, and ET = 50v
.5 amps
20 milliamperes is the same as __________ (remember 1 milliampere = .001
0.02 amperes
1 millivolt(mV) decrease in signal level of 40 dBmV is approximately equivalent to a decrease in level of
0.1 dB
What does 0 decibel millivolt (dBmV) equal?
1 mV across 75 ohms
The input-to-output power ratio of a coaxial cable that has 1dB of attenuation is
1.2589:1
The power ratio for 2dB is
1.585:1
The input-to-output power ratio for 2 bels of similar impedance cable is
100:1
Which of the following are the aeronautical frequency bands?
108-137 and 225-400
How much signal is necessary from the subscriber's tap port @759MHz to provide a minimum of 3.0 dBmV to the TV set when the drop is 150 feet series 6 cable and just one outlet (use 5.65 dB per 100 feet for the attenuation rate and round off to the nearest tenth of a dBmV)?
11.5 dBmV
A DC series circuit where R1=50 ohms, R2= 100 ohms, R3=183.33 ohms, IT= 0.6 ampres, and ET = 200 volts consumes ____________ watts of power.
120
What is the total voltage of a DC series circuit where ER1= 20v, ER2=45V, and ER3=57V
122V
What is the total DC loop resistance of a 350-foot piece of series 59 drop cable when the DC loop resistance of that Series 59 cable is 56.04 ohms per 1,000 feet?
19.614 ohms
The total dc loop resistance of a 1,850 foot piece of .500 inch coaxial cable with a DC loop resistance of 1.34 ohms per 1000 feet is
2.479 ohms
When using an optical coupler, a desired split ratio of 40/60 will result in an insertion loss of
2.7 dB
According to the FCC, leaks ______________ and above measured ______________ feet from the cable must be logged and repaired
20 microvolts/per meter, 10
1:5 ratio is equal to
20%
A signal increase of 1dB represents a_______________ increase in power.
25.89 %
The circuit current is ___________ amps in a DC series circuit where R= 40 ohms and E= 120V
3 amps
5 kilovolts is the same as
5 kV
R2= ______ ohms in a DC series circuit where R1= 33 ohms, R3= 47 ohms, R4= 56 ohms, and RT= 197 ohms
61
A length of coaxial cable that has an attenuation of 10dB will experience an input RF signal power loss of ________________, with _________________________ of the signal remaining
90%, 10%
Which of the following is a correct definition for a type of circuit graphic?
A block diagram is a simplified outline of an electrical system that shows circuits or parts as rectangles and other shapes.
A number that compares an amount that is less than the whole to the whole amount is
A fraction
Why is a leakage detector preferable to a signal level meter (SLM) for detecting leakage?
A leakage detector has an increased sensitivity to weak signals
What is the design difference between a loop-through system and a home-run system?
A loop-through system has a splitter or directional coupler at each outlet that provides signal to those outlets and passes the remaining signal to the next outlet, while a home-run system has a dedicated cable run to each outlet from a common splitter
Voltage is
A measurement of the force or pressure that causes electrons to move
What are the three basic elements of an electrical circuit?
A power source, a load, and the connecting conductor
Which is the best amplifier to use when the digital set-top box (STB), cable modem , or EMTA is unable to consistently and reliably transmit information back to the headend because of a long-cable drop run
A return path (reverse or upstream) amplifier
It is essential to pay attention to warning signs of stress overload. Poor attitude is one of the behaviors that may indicate that you are over stressed. What are the symptoms of poor attitude behavior?
A significant change in attitude with a noticeable movement toward, negative, hostile, cynical, or paranoid thoughts
What is the purpose of a tagger when detecting and measuring signal leakage?
A tagger will ensure any leak measured emanates from the cable system
Acceptable leakage limits per the FCC specify a maximum acceptable field stregth of 15 V/m(micro-volts/meter) at 30 meters for frequencies
Above 216 MHz
An ohmmeter should be connected
Across a resistor that is disconnected from the circuit voltage source
Magnetic poles that are _________ will _________ each other when those poles are near each other
Alike, repel
Flux lines
Always curve around through the body of the magnet to form complete loops
The return amplifier
Amplifies the return signals for transmission to the next return amplifier upstream, relative to the forward path
A passive component that reduces signal amplitude equally at all frequencies in a distribution amplifier is
An attenuation pad
During the six-step troubleshooting process, you need to ask the customer questions such as, "have any other contractors worked at the premises lately?" What step in the process do such questions most closely resemble?
Analyze the situation
How far should an aerial drop cable be placed from the power utility feed where the cables attach to the premises?
At least 12 inches
In analyzing faults at the customer premises, you will need to determine if the problem is localized or encompasses a larger are of the cable system. If the problem is affecting the whole house, how should you proceed?
Begin your isolation at the ground block
How can the proper operation of a leakage detector in a monitoring vehicle be verified?
By creating a test leak
Some set-top boxes with poor shielding can cause which of the following problems?
CB or ham radio interference and ingress on all cable channels.
Which category of wiring reduces both Near-End Crosstalk (NEXT) and attenuation due to a larger gauge conductor?
Category 6 (CAT-6)
A common problem at the ground block is common path distortion (CPD). What usually causes CPD?
Corrosion
The magnetic field
Created by a straight piece of wire is weaker than that created by forming loops of wire
Once you have restored the operations of the customer's service, how should you communicate this to the customer?
Describe the nature of the problem and what you did to correct it
The strength of an electromagnetic field is
Determined by the magnitude of the magnetomotive force (mmf)
The FCC requires the use of a ___________ antenna for the measurement of signal leakage for logging and Cumulative Leakage Index (CLI)
Dipole antenna
Which of the following is most likely to reduce signal quality on a fiber-optic transmission as opposed to causing a catastrophic failure?
Dirt on the connector
In the forward direction, optical spitters are passive branching devices that
Divide an optical signal across a number of output fibers.
A fraction is converted to a percent by
Dividing the numerator by the demominator and multiplying by 100
Resistance
Doubles when the length of a conductor doubles
Which activity encourages creative thinking?
Drawing
the recording head of a tape recorder is actually an
Electromagnet
Digital artifacts can be caused by impulse noise. What is impulse noise?
Electromagnetic signal interference produced by power-line transients, motor arcing, household appliances, or electrical systems without shielded wiring
Direct current
Flow is a continuous electron flow in the same direction
Current
Flow that is excessive for a specific size of conductor can cause the conductor to become too hot and melt or burn the conductor's insulating cover.
A permanent-magnet loudspeaker
Has a cone that moves back and forth in relation to the varying current of the original sound
A semiconductor material
Has four valence electrons.
Elements that are called conductors
Have very few valence electrons
The letter and symbol designation for current is ____________ and ___________________ , respectively
I and A
Which of the following is a method for controlling expectations?
Identify the source of emotional overload
the left-hand rule for electromagnetism in a wire states that
If you wrap the fingers of your left hand around the wire with your thumb pointing in the direction of the current flow, your fingers will be wrapped in the direction of the magnetic field
Where only some of the magnetic domains are pointing in the same direction, the magnetic field is weaker
In magnetic material
What signal leakage information and measurements must be included with the annual reporting to the FCC
Information carried on signals in the aeronautical bandwidths
What is the process for checking for ingress at a drop splitter at the customer premises?
Inspect the splitter and confirm that all of the splitter's F-connectors are properly wrench-tightened by using a 7/16-inch torque wrench
Load resistance
Is considered to be the total resistance when the source and wire resistances are very small
Excessive current flow
Is often the result of the failure of a small part within a larger circuit
The load
Is the part of the electrical circuit that uses the electrical energy provided by the power source to carry out some desired function
You are at a customer's home and you are asking the customer whether the problem is intermittent or constant. Which step are you using from the six-step troubleshooting process?
Isolating the elements
Which of the following is a feature of the signal level meter (SLM)?
It can be used in sweep mode to identify instances of ingress.
Why is Series 59 coaxial cable no longer used?
It has poor signal loss characteristics
Which of the following is true of fiber-optic pigtail splicing?
It is faster and more reliable than installing connectors in the field.
Loose-tube fiber-optic cable is used for what purpose?
It is used as the main cable between the headend and node.
When the cross-sectional area of a conductor doubles,
Its resistance decreases to half its original value
When using the optical time domain reflectometer (OTDR) to troubleshoot fiber-optic cable, locating a reflective event means
Light intersects with a material (like air), causing it to bend differently than if it was traveling within the fiber
What type of loss occurs in a transmission line when the fiber-optic bend radius decreases?
Macrobending
An optical power meter (OPM) is used to
Measure the power in an optical signal.
What unit of measure is used to identify the field strength of electromagnetic radiation (signal leakage)
Microvolts/meter
What are the units that can be used to represent signal level values?
Millivolt(mV), decibel millivolt (dBmV), and microwatt or nanowatt
Why should you take the time to take notes and accurately record data at each job location?
Notes and recorded data are tools that can help you accurately remember events at a site that can help you determine a plan of action or evaluate the decisions you made.
When troubleshooting a drop splitter with wrong cable connections, incorrectly connecting the input cable to a splitter's output port and the TV cable to the input port of the splitter will usually result in which of the following?
On the TV set incorrectly connected to the splitter input port will have a good picture, while all the TV sets connected to the other output ports will have black pictures.
most line extender housings have
One input port for receiving the forward RF signals and one or two output ports for distributing the amplified forward RF signals.
When checking for ingress at the tap, when would you replace the drop cable between the ground block and the customer's tap?
Only if necessary as a last corrective measure.
The line extender amplifier housing has
Plug-in connectors that direct the incoming forward RF signals from the input port to the RF amplifier module and the outgoing amplified signals from the amplifier module to the output port.
Which of the following best describes stereotyped thinking?
Presuming that all members of a group have certain characteristics
A conductor
Provides a path for the current flow from the power source to the load and from the load back to the power source
What are the FCC requirements regarding leakage monitoring?
Quarterly monitoring and annual reporting
Across which resistor in a DC series circuit where R1=25 ohms, R2= 50 ohms, R3=75 ohms, and R4= 10 ohms is the greatest voltage drop?
R3 with the most ohms
Which of the following refers to an eight-pin, eight eight-conductor plug and jack capable of supporting Ethernet and telephone?
RJ45
Which colors are used on a telephone station jack?
Red/green yellow/black
What should be done to correct signal leakage from a drop splitter with a defective cover plate?
Remove and replace the splitter
The line extender amplifier
Requires the AC input voltage typically to be received through the port seizure screw connection
Which of the following connectors uses a bayonet coupling mechanism?
ST connectors
When adjusting amplifier controls, remember that
Signal level controls compensate for slight variations in the input signal level caused by temperature changes and by signal loss from coaxial cable and passive devices
What is ingress?
Signals leaking into the cable system
The metal that has the greatest conductance is
Silver
Which of the following wiring is used to connect speakers to an audio source?
Stranded two-wire
Which of the following is one of the common sources of over-the-air ingress?
Strong over-the-air television channels
When applying the six-step troubleshooting process for improving one's behaviors and attitudes, which of the following can be used to help resolve a problem?
Talking yourself through the task
The term "bel" originated with the early days of
Telephone
One-tenth of bel or 1 dB is
The 10th root of the 1 bel ratio
Which wiring standard is used in all modern ethernet data cables, jacks, and connectors?
The TIA/EIA 568B standard
What test equipment automatically identifies specific wiring problems on four-pair UTP/STP patch cords and station wiring?
The UTP/STP test set
Indicates how many coulombs pass a given point during 1 second
The ampere
What prevents the electrons that orbit an atom's nucleus at high speeds from breaking away from the nucleus due to centrifugal force?
The attraction between the positive nucleus and the negative electron
When taking bit error rate (BER) readings, the pre- and post-forward correction error (FEC) BER are important to know. The harder the FEC is working,
The closer the system is to failure
The resistance of a conductor increases as
The cross-sectional area of a conductor decreases
The majority of ingress is caused by which of the following?
The customer
To determine actual insertion loss on a two-way splitter, the input level at a particular frequency and the output port levels at the same frequency are measured. What is the actual insertion loss of the output port?
The difference between the splitter's input level and the measure output level of that port.
In the forward signal path of the line extender
The first equalizer is where the frequency-dependent attenuation (tilt), caused by the coaxial cable between the line extender and the previous upstream amplifier, is corrected.
Which of the following is true when connecting a device to the correct AC to DC power supply?
The input ampere rating is the maximum load the supply will draw on the 110 AC circuit
When visually identifying correct cable connections for a directional coupler in an attic with a loop through system, which cable usually comes from the outside wall, which cable typically goes down the wall to the TV, and which cable typically continues on through the attic to another section of the house?
The input cable usually comes from the outside wall, the tap port cable typically goes down the wall, and the output port cable typically continues on through the attic to another section of the house.
When measuring inadequate port-to-port isolation in a drop splitter, the higher the amount of isolation between the splitter output ports,
The less chance of passing radio frequency (RF) interference from one TV set to the other.
The term voltage normally refers to
The measurement of the difference in potential between two charges
The major factor for determining whether a particular elements is a conductor, a semiconductor, or an insulator is
The number of electrons in the valence shell.
If there is no signal on the input cable to the second directional coupler in a loop through drop system, what is the likely cause?
The output cable of the first directional coupler's output port was disconnected
which is true
The resistance of a material with a negative temperature coefficient will decrease as the temperature increases
In a DC series circuit
The same amount of current flows through each component
When the output of a line extender is 3dB lower than it normally should be
The signal is 3 dB lower than normal from that point on
Operation gain is
The signal level difference between the input signal and the output signal
what is the theoretical output level and the actual output port insertion loss of a two-way splitter when 1) the measured input level to the splitter is 9 dBmV @197 MHz; 2) the manufacturer-specified insertion loss is 3.5 dB @ 403 MHz, and 3) the measure output port level is 4 dBmV @ 197?
The theoretical output level @ 197 is 5.5 dBmV and the actual output port insertion loss is 5 dB
What test equipment measures cable lengths and locates faults on both twisted pair and coaxial cable?
The time domain reflectometer (TDR)
The "bypass current capacity" is
The total AC current the line extender amplifier can pass through to other active devices.
Which of the following is true
The total resistance(RT) of a DC series circuit is the sum of the individual resistance in the circuit (RS+RW+RL)
Electric current is actually produced by
The transfer of energy from valence electron to valence electron as a result of applied charges
What relationship between very high frequency (VHF) and ultra-high frequency (UHF) leakages and ingress?
There is little or no relationship between VHF and UHF leakage and ingress
Through wich resistor in a DC series circuit where R1=10 ohms, R2= 15 ohms, R3 =20 ohms R4 =5 ohms is the greatest current flowing?
They all have the same amont of current flowing through them.
Values expressed in dBmV prgress in a nonlinear fashion when compared to a linear millivolt (mV) scale because
They are based on the logarithms of power ratios.
Which of the following statements describes creative problem solving?
Thinking outside of the box and looking at problems from a fresh perspective
The orbital shell that has a maximum electron capacity of 18 electrons is the ______________ shell
Third
When closing any distribution amplifier housing,
Tighten the bolts to the recommended torque in the proper tightening sequence, using an appropriate torque wrench
Values expressed in dBmV that are preceded by a minus sign (-) represent
Values of voltage less than 1 millivolt (mV) across 75 ohms
What type of fiber-optic attenuator is used to check out and optimize network performance by adding loss, typically from 0 to 65 dB, in either stepped or continuous movements?
Variable attenuator
When locating live cable, after placing the coupler around the cable in question, what should be done next?
Walk around the pedestal to locate the strongest signal.
Normal current flow results
When the circuit operates properly and no damage occurs to the circuit components
Magnetism
Where only some of the magnetic domains are pointing in the same direction, the magnetic field is weaker
When examining a power cord for damage, what part of the cord is the most vulnerable?
Where the cord meets the plug
To create an electromagnet
Wrap a coil of insulated wire around an iron bar and pass an electric current through the wire
The attribute of being "active" as a critical thinker means?
You observe and take notes relevant to the issue
What kind of reasoning is described as applying a general statement that you know to be true to a new situation?
deductive reasoning
A symbol
is a simple line design used to represent a component or device in a schematic circuit diagram
The power source
is the part of an electrical circuit that provides a difference of potential
Which of the following is true about 110-type punch-down blocks?
they are used to connect data jacks to service provider cabling
An input-to-output power ratio of 10:1 has an input-to-output voltage ratio of
3.162:1 the square root of the power ratio
ER2= __________volts in a DC series circuit where R1= 150 ohms, R2= 150 ohms, R3= 550 ohms, and IT= 0.2 ampres.
30 volts
The deployment of _____________ for use as a pulic safety communications technology will greatly increase the importance of controlling and reducing leakage and ingress issues
700 MHz Long Term Evolution (LTE)
Which of the following is the frequency allocation dedicated specifically to public safety communications?
700 MHz Long Term Evolution (LTE)
How can an installer control the resistance of the drop cable being installed at the customer premises?
Install series 6 cable instead of series 59 cable because series 6 cable is larger diameter with lower resistance , than series 59 cable
