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230 Cards in this Set

  • Front
  • Back
Aural communication
Wireless telegraphic transmission became practical many
years before the vacuum tube was perfected.
Concerning the history of visual communication,
Arpanet's descendants form the global backbone of the
Internet.
Modulation
May be high-level or low-level, depending on the point in
the system at which the modulating signal is injected.
Which of the following is not a type of modulation used by
communications systems?
Shield modulation.
In the transmitting and receiving of signals
The receiver must filter out the unwanted noise signal,
select the desired frequency, and amplify the weak signal
enough to overcome any internal noise generated in the
receiver.
External noise
May be caused by atmospheric conditions, including space,
solar, and cosmic noise, or it may be man-made.
Internal noise
Is proportional to the bandwidth over which it is measured.
Noise figure
Is defined as the ratio of the S/N at the input of the
receiver to the S/N at the output of the receiver.
Bandwidth and resonant frequency.
Bandwidth is the width of the band of frequencies centered
on the resonant frequency, and depends on the quality of
the tuned circuit.
Information transfer
Reliability can be increased when system design incorporates
every possible noise-limiting device available to minimize
noise effects.
Modulation is
A process done at the transmitter.
A technique of modulation is
Frequency modulation, where the frequency of the carrier
changes in accordance with the amplitude of the input
signal, but its amplitude remains unchanged.
Modulation can be identified by
The intelligence signal's varying voltage applied to a
carrier, known as amplitude modulation.
Which of the following describes phase modulation
techniques?
Phase modulation is easily adaptable to data or digital
applications.
In pulse modulation,
Analog techniques are pulse amplitude modulation (PAM),
pulse position modulation (PPM), and pulse width
modulation (PWM).
Multiplexing
Is the process in which two or more signals are combined
for transmission over a single communication path.
In frequency division multiplexing,
A two-way communications circuit requires a
multiplexer/demultiplexer at each end of the
long-distance, high-bandwidth cable.
For a T-1 carrier using time division multiplexing,
Twenty-four voice channels are multiplexed into a digital signal.
Statistical time division multiplexing
Uses a statistical multiplexer that has an aggregate
transmission bandwidth that is less than the sum of
individual channel bandwidths.
Wavelength division multiplexing
Systems make use of the optical fiber's available intrinsic
bandwidth by multiplexing many wavelengths of coherent
light along a single-mode optical fiber channel.
According to SCTE- and NCTA-recommended trunk system map
symbols, fiber-optic cable is represented by
Double arrows within a small circle on a solid line
The forward path signal in a traditional tree-and-branch
architecture
Originates at the headend and is transmitted downstream
through coaxial trunk cable and trunk amplifiers.
In an HFC network,
Processing equipment in the headend converts the forward RF
signal to a light signal.
During aerial plant construction,
The strand is tensioned so its sag profile matches that of
the overhead utility power lines.
With underground plant construction,
The fiber-optic and coaxial cables are often placed
underground with other utility lines to jointly share
construction costs.
Standby power supplies
Continue providing an output voltage even during a utility
power outage by using a backup power source.
Centralized power configurations
Provide the advantage of increased reliability through
sharing of expensive backup generators and sophisticated
monitoring equipment among different power realms.
When transmitting broadband signals
In a two-way HFC network, two or more individual optical
fibers are required for each optical node location.
RF trunk amplifiers
Have attenuator pads, equalizers, and diplex filters that
control and route the RF signals.
Verifying plant reliability includes
Frequency response sweeping, which is adjusting RF amplifier
circuits to amplify all frequencies in the bandpass
spectrum as equally as possible.
Regarding the half-wave rectifier,
When the rectifier diode is reversed, the polarity of the
output from the half-wave rectifier is reversed.
Regarding the full-wave rectifier,
From center tap to either end of the secondary, the voltage
equals only half of the full secondary voltage.
Regarding the bridge rectifier circuit
Semiconductor manufacturers simplify the actual circuitry
of this rectifier by providing the four-diode bridge
assembly in a single package.
Which of the following statements about rectifier circuits
is not true?
The high cost and low reliability of bridge rectifier
assemblies make them the worst choice for most practical
applications.
In a power supply system,
An optional regulator provides an especially smooth and
constant output voltage or current level.
A C-type power supply filter
Is used when a relatively large amount of ripple does not
seriously affect the operation of electronic devices that
operate from it.
Which of the following statements about power supply
filter networks is true?
Three of the main considerations in the selection and
quality of a power supply filter are the allowable output
ripple, allowable minimum regulation, and rectifier peak
current limits.
The power supply ripple
Percentage is calculated by dividing the AC amount by the
DC amount and multiplying by 100.
The voltage regulator
Instantly makes an internal adjustment that causes the DC
output to remain steady whenever the DC output tries to
change.
Which of the following statements about troubleshooting a
power supply is not true?
A rectifier can be checked while it remains in circuit by
measuring its forward and reverse resistance with a
DMM.
In the bipolar junction transistor,
Terminals are called the collector, the base, and the
emitter.
The purpose of a heat sink in a transistor is to
Provide a heat conductive metal to the surface of the
transistor.
In a transistor schematic, the collector current is
commonly referenced as
Ic
Which of the following statements about biasing in a BJT
is not true?
Base currents for BJTs are usually limited to the
milliampere range.
In the normal operating conditions of a BJT
The internal current flowing from the emitter to the
collector is far more current than the forward-biased
base-emitter junction.
The DC model of an NPN transistor
Models the collector-emitter junction of the transistor
as a current-controlled source.
The BJT
Can be used as a switch, an amplifier, or both.
Which of the following statements about BJT ratings is
true?
If the reverse-bias value of collector-base voltage is
exceeded, the voltage will break down the collector-base
junction and destroy the transistor.
The amount of change in collector current divided by the
corresponding amount of change in base current
Is expressed as AC beta.
In testing a BJT that has failed,
perating the circuit in its normal system or placing it in
a test jig that simulates the function of the rest of the
system is performed in dynamic testing.
The output signal level of a bipolar junction transistor
(BJT) can be related to the input signal level by
The gain of the amplifier.
Transistor circuit bias is
Created by applying constant values of DC current and
voltage to the transistor junctions.
Voltage divider biasing is established by
Using two resistors connected to the input of the
transistor to bias the base voltage.
An identifying characteristic of a common-emitter amplifier
is
Both input and output connections are taken with respect to
the emitter terminal
In an amplifier circuit using a common-emitter
configuration
The collector output voltage will decrease when the base
current increases.
A common-collector amplifier
Is a circuit where the base terminal receives the input
signal and the emitter terminal provides the output
signal.
A circuit using a common-base amplifier will likely have
The emitter terminal receiving the input and the output
taken from the collector terminal.
The primary difference between small-signal amplifiers and
large-signal amplifier circuits is
Based on the power they can handle.
An operating characteristic that can be used to determine
whether an amplifier is operating as class A, B, AB, or C, is
The location of the Q-point
Push-pull amplifiers are a common application in cable
television distribution networks. If one stage of the
push-pull amplifier develops a problem the result on the
output signal will be
Distortion will increase on the output and there will be a
3 dB decrease in the power output.
The operational amplifier
Stages are direct coupled, with one stage's output coupled
directly into the next stage's input.
In the op-amp,
There is something less than a flat frequency response
when attempting amplification from DC to radio frequencies.
Which of the following statements about the differential
amplifier is not true?
A differential amplifier amplifies the difference between
the two input waveforms to where the output is divided by
the difference between the two inputs.
Regarding the inverting amplifier,
If the input signal is a sine wave, then the output signal
is an inverted sine wave (180 degree phase shift).
Active filters
Pass a specified range of frequencies to the output and
block all other frequencies from reaching the output.
The bandpass filter
Bandwidth is calculated by dividing the quality factor
(Q) by the center frequency of the filter.
In the single-ended input mode of operation,
One input is connected to the input signal and the other is
connected to ground.
Regarding the comparator circuit,
The waveform at the output does not necessarily resemble the
waveforms at the input.
A differentiator circuit
Produces an output voltage proportional to the rate of
change of voltage at the input signal.
The Schmitt Trigger circuit
Always shows a difference between upper threshold point
and lower threshold point values.
In regard to the oscillator
Its function depends upon the qualities of inductor and
capacitor (LC) tuned circuits or resistor and capacitor (RC)
phase-shift circuits.
In the operation of an oscillator,
) Decoupling capacitors are used to bypass (short-circuit)
any stray oscillations from the power supply lines to
ground.
With the Hartley oscillator,
The operating frequency (or oscillating frequency) can be
calculated by applying the basic parallel LC circuit
formula for resonance: fr = 1/2π √LtC
The Colpitts oscialltor
Has a grounded tap between a pair of series capacitors,
unlike the Hartley oscillator.
The Clapp oscillator
Inserts a third capacitor into the tank circuit as a way to
stabilize operation when the input impedance of the next
stage changes.
Which of the following statements about crystal oscillator
operation is not true?
The rate that the crystal vibrates is determined solely by
the voltage supplied by the amplifier.
For the phase-shift oscillator,
Oscillation occurs only at the frequency that causes a
180 degree phase shift through the RC network.
In the Wien-bridge oscillator,
The amplifier is of the noninverting type, thereby
producing zero phase shift between input and output
signals.
The monostable multivibrator
Is constructed from integrated circuits that replace
transistors and most of the resistors, and rarely from
discrete components.
Regarding the astable multivibrator,
It has no stable state and produces its output as a result
of continually seeking a stable state.
A trunk/bridger amplifier housing
Typically has test ports for measuring the trunk RF input
level, the trunk and bridger RF output levels, as well as
return video carrier input signal levels, without having
to open the amplifier housing.
A feed-forward trunk amplifie
Utilizes multiple amplifiers and delay lines to produce a
cancellation of distortions, while increasing the
amplifier's output level.
Which of the following statements is true?
When closing any trunk/bridger amplifier housing, visually
inspect the housing and confirm that the gaskets are in
place.
A push-pull trunk amplifier
Type has characteristics that include high operating
efficiency, second order distortion cancellation, and
minimal hum.
A trunk amplifier module
Must operate at the optimum input and output levels to keep
all forms of amplifier-caused degradation (noise and beats)
to a minimum.
A power doubling or parallel hybrid trunk amplifier
Has a better carrier-to-noise ratio than the typical
push-pull trunk amplifier.
The trunk amplifier equalizer
Compensates for the unequal signal level attenuation of the
coaxial trunk cable.
The bridger amplifier's manual slope control
Adjusts the relative levels of output carriers of the
bridger amplifier to compensate for the feeder cable loss.
Which of the following statements is true?
It is necessary to add the test point attenuation to the
carrier level reading when computing the actual output
level with a signal level meter.
What would be the actual input carrier levels if the
measured input carrier level readings at the trunk
amplifier's -30 dB input test point are -16 dBmV at 542.25
MHz and -9 dBmV at 67.25 MHz?
Levels of 14 dBmV at 542.25 MHz and 21 dBmV at 67.25 MHz.
The return amplifier module
May have an equalizer located on the input or output of the
return amplifier.
Which of the following is not true about a DC power supply module
in a trunk/bridger amplifier housing?
It receives a 30 VAC power supply from the AC distribution
board.
The control module in a trunk amplifier station
May be an AGC/ASC module inside the trunk amplifier module,
a separate complete control module mounted on the chassis,
or an automatic control module mounted on the housing.
Which of the following statements is true?
The downstream data signals may be used to monitor the: (1)
amplifier station's forward RF pilot signal levels; (2)
return level; (3) amplifier housing's open/closed status;
(4) temperature of the amplifier; (5) module's failsafe
position; (6) status of standby power supply; (7) DC power
supply voltage; and (8) open close, or attenuate by 6 dB
the return feeder switch.
A trunk/bridger amplifier station
Uses housing or chassis connections to distribute the AC/DC
voltage to its modules.
The module that causes the trunk input signal to bypass the
trunk amplifier, continue to the next amplifier station
downstream, further causing the return signals to bypass the
return amplifier is the
Failsafe module.
The slope control
For a typical return amplifier module has a range of 6 dB.
Which of the following statements is true?
The return RF signals may be data (status monitoring signals
and/or customer impulse pay-per-view buy signals) or a
return video carrier signal.
In the C-COR return amplifier,
The return amplifier receives its input signal from the
output diplex filter in the trunk amplifier module.
In the return amplifier,
The thermal compensated gain control compensates for changes
in return signal level due to temperature variations.
When measuring the AC input voltage of a C-COR 750 MHz FNT
distribution amplifier,
Touch one DMM test lead probe to the AC input voltage test
point and the other test lead probe to a suitable ground point.
To properly select a forward station equalizer for the C-COR
750 MHz FNT distribution amplifier,
Determine the proper forward station equalizer value for the
trunk output by first determining the actual RF carrier levels.
When selecting the forward station attenuator pad for the C-COR
750 MHz FNT distribution amplifier,
Calculate the required pad value by subtracting the system-
required from the actual highest video carrier levels.
To properly select a forward bridger attenuator pad for a C-COR 750 MHz
FNT distribution amplifier,
Calculate the attenuator pad value by subtracting the
system‑required highest carrier level from the actual highest
carrier level.
When selecting a reverse attenuator pad for the C-COR 750 MHz
FNT distribution amplifier,
Connect the signal generator to the amplifier under test
and connect the SLM to the first amplifier upstream of the
amplifier under test.
With a fuse installed in only fuse location #6 of a Texscan 750 MHz
FTMT distribution amplifier, the AC input voltage can pass from
Port 1 to the DC power supply only.
When measuring the DC power supply output voltage of a Texscan
FTMT 750 MHz distribution amplifier,
Verify the DC voltage is within the range of 23.5 volts to
24.5 volts.
What is the resulting input slope at the preamplifier in a Texscan
750 MHz FTMT distribution amplifier when: (1) the actual lowest
input carrier level is 19 dBmV; (2) the actual highest input carrier
level is 15 dBmV; (3) the installed input equalizer has an insertion
loss of 6.7 dB at the lowest carrier; and (4) the installed input
equalizer has an insertion loss of 1.25 dB at the highest carrier?
1.45 dB
When adjusting the manual ASG control for the Texscan FTMT
750 MHz distribution amplifier,
Adjust the manual ASG control until the pilot carrier level
matches the system-required carrier level.
When selecting a reverse equalizer for the Texscan FTMT
750 MHz distribution amplifier,
Calculate the required reverse equalizer value by subtracting
the actual highest from the actual lowest reverse video
carrier levels.
When selecting the AC voltage direction in a distribution amplifier,
Identify the fuses and/or circuit breakers needed to route the
AC voltage to meet system powering requirements.
When measuring the AC input voltage on a Scientific-Atlanta System
Amplifier II,
Touch one DMM test lead probe to the AC input voltage test point
(RMS) and touch the other test lead probe to a suitable ground point.
When measuring the regulated DC output voltage in a distribution amplifier,
which of the following is an incorrect step?
Prior to starting, verify the AC voltage is between 15 to 20 volts.
When determining the input equalizer value for a Jerrold Mini-Bridger
amplifier,
Select an equalizer value (if needed) that is closest to the required
input equalizer value.
When verifying the input attenuator pad value for a Scientific-Atlanta
System Amplifier II,
Connect an SLM to the forward main output RF test point.
When checking the secondary output levels on a Philips GNA distribution amplifier,
which of the following is an incorrect step?
Connect a jumper cable between the RF output of a signal generator and Port 3
When setting the manual gain control on a Jerrold Mini-Bridger amplifier,
Select an attenuator pad value to obtain the correct output carrier
level, if the actual highest carrier level is greater than the system-required
carrier level by more than 0.5 dB.
When preparing to adjust the reverse equalizer control on a Scientific-
Atlanta System Amplifier II,
Determine if the actual slope at the first reverse amplifier upstream
is flat or meets system requirements.
When selecting the reverse output attenuator pad value on a Jerrold
Mini-Bridger amplifier,
Choose an attenuator pad, if required, that offsets the reverse video
carrier level difference to obtain the system-required reverse input
carrier level at the upstream amplifier.
When adjusting the reverse gain control on a Philips GNA distribution
amplifier,
Adjust the gain control as required to match the actual highest reverse
video carrier level (at the upstream amplifier) with the system-required
highest reverse video carrier level.
Troubleshooting a problem using a six-step process requires
you begin by
Identifying the problem.
Which of the following statements about common fault
categories is not true?
An intermittent fault is the easiest to diagnose because it
is relatively easy to keep the problem consistent.
When the technician makes measurements,
The resulting data will require analysis which consists of
comparing the recorded measurement to a standard.
Using the signal tracing method, troubleshooting a
superheterodyne receiver with no sound from the speaker
requires
Measuring if a signal is present on the output of the IF
amplifier, once the power supply has been checked.
Using the signal injection method, troubleshooting a
superheterodyne receiver with no sound from the speaker
requires
Examining the stages prior to the injection point when tone
is present at the speaker.
Which of the following statements about sweep generators is
true?
A calibrated attenuator reduces the sweep generator output
to an amount specified by the user.
A digital multimeter (DMM)
With a four-digit display gives a resolution of one part in
10,000 or 0.01%.
Which of the following statements about frequency
synthesizers is not true?
Heterodyning has a disadvantage by not allowing a frequency
synthesizer to work with higher frequency ranges.
Low-frequency oscillations
Can be prevented by making sure that the power supply for
the communications system is well-regulated or by replacing
the output filter capacitor when needed.
In troubleshooting power supplies,
Keep nickel-cadmium charging cells well vented and away from
sparks or open flames.
Which of the following statements about low-pass filters
is true?
When an inductor is used for the series component, there is
an increasing opposition to current at higher frequencies.
The range of frequencies passing through a filter with
maximum gain or minimum attenuation is called the
Passband
In a series resonant circuit,
The current in a series resistive/inductive/capacitive (RLC)
circuit is in phase with the voltage across the circuit.
In a parallel resonant circuit,
Often called a tank circuit, energy is stored by the
inductance and capacitance.
In regard to resistor-capacitor oscillators,
The phase-shift oscillator is usually used only in fixed-
frequency applications.
With respect to inductor-capacitor oscillators,
In the Clapp oscillators, the frequency of oscillation is
relatively unaffected by changes in active device
parameters, which provides added stability.
For crystal oscillators,
The crystal must have the qualities of generating a voltage
across its faces when subjected to mechanical pressure and
compressing when a voltage is applied across its faces.
Which of the following statements about amplifier circuits is not true?
In a common-collector amplifier circuit, the collector is common
to both the input and output signals, with the emitter and base leads
serving as input and output leads, respectively.
In regard to coupling circuits,
There is no lower frequency limit when using direct
coupling; all frequencies down to DC, or 0 Hz, are
amplified.
In the operating classes of amplifier circuits,
A class C amplifier is useful only when we want to amplify a
narrow band of radio frequencies.
Which of the following statements about the amplitude
modulation waveform is not true?
When the signal is viewed on an oscilloscope, the
intelligence envelope may be visible.
Regarding the modulation factor,
It is the variation in the AM signal compared with the
unmodulated carrier.
Which of the following is not a disadvantage of standard AM signals?
The standard AM system uses expensive transmitting and
receiving equipment.
With respect to high-level modulation,
In general, a crystal oscillator is used for stability if
the transmitter is to be used at a standard fixed frequency.
The sensitivity of a receiver
Is determined by the amount of gain a receiver has.
For superheterodyne receivers,
The principle of fixed tuning is used, mixing the incoming
RF signal with a signal generated within the receiver.
The balanced modulator
Type called the balanced ring modulator is capable of
suppressing the carrier by 60 dB, but the diodes must be
carefully matched.
The filter method of sideband suppression
May use piezoelectric crystals to produce the narrow
passbands and sharply defined skirts required to properly
filter out the unwanted sideband.
The automatic gain control
System can be achieved with conventional diode rectifiers
and additional amplification.
Which of the following is not an advantage of single-
sideband communications systems over standard AM systems?
SSB offers more cost savings and system simplicity than
standard AM.
Which of the following statements about deviation in FM
systems is true?
The amount of deviation is determined only by the amplitude
of the modulating signal.
Noise
Can be introduced into any system at any point where
amplitude-controlled phase- or frequency-sensitive circuits
are used.
The required bandwidth for an FM signal with a maximum
deviation of 36 kHz when modulated with an intelligence
frequency of 9 kHz is
126 kHz
The reactance modulator
Circuit must be totally reactive and have either a
+90 degree or a -90 degree phase angle for proper
operation.
In phase modulation,
Deviation is directly proportional both to modulating audio
voltage amplitude and to the audio voltage frequency.
The frequency multiplier
Circuit output is a harmonic of the fundamental input
frequency.
The intermediate frequency
Was chosen to provide good image frequency rejection and
wider bandwidth required for FM broadcast signals.
Which of the following statements about demodulators is
not true?
The greater the deviation of the signal frequency below
the channel center, the greater the negative voltage at the
output of the discriminator.
The phase-locked loop
In its basic form consists of a phase detector, a DC
amplifier, a low-pass filter, and a voltage controlled
oscillator.
Which of the following statements about pre-emphasis and
de-emphasis is true?
Pre-emphasis improves noise suppression by increasing the
modulation index at higher modulating frequencies.
As you analyze signals carried by the broadband cable system, it
is important to understand what you are looking at. Which signal
domain are you viewing when you use a spectrum analyzer?
Frequency.
A spectrum analyzer uses a superheterodyne receiver to tune
the incoming signal. Which frequency does the superheterodyne
receiver mix with the incoming frequency?
The local oscillator frequency.
One of the many functions of the automated spectrum analyzer
is to measure noise and beats on analog-modulated television
channels. Which part of the spectrum analyzer’s circuitry is used
to detect the sync tip?
The envelope detector.
You are performing a series of in-service tests using an automated
spectrum analyzer. What additional equipment do you need to
measure composite triple beats (CTB)?
A quiet line interruption device.
A constellation display shows the condition of the QAM signal. What
type of signal impairment is represented by a circular pattern?
Phase noise.
You are analyzing a QAM signal with the constellation display on
an automated spectrum analyzer. The points are spread out across
the grid lines in no discernible pattern. What type of signal noise
does this represent?
Thermal noise.
Modulation error ratio (MER) is a relative measure of signal
performance. In a 256-QAM signal, which of the following MER
readings would indicate that the signal is beginning to fail?
28dB MER
On an automated spectrum analyzer, several settings control
the signal levels being measured. Which of the following settings
controls the amount of signal being swept?
Span.
Both the oscilloscope and the spectrum analyzer display signal
amplitude. Over which domain does the oscilloscope display
amplitude?
Time
You are using an automated spectrum analyzer. What setting
would you use to change the amount of time that the analyzer
samples the signal?
Sweep.
Control Leakage Index Data Easily (CLIDE) and Leakage
Evaluation System (LES) are the major Windows-based software
programs available for signal leakage documentation and
analysis. What are these software programs used with to comply
with Federal Communications Commission (FCC) signal leakage
annual reporting?
Ground-based measurements of signal leakage.
A system's cumulative leakage index (CLI) can be calculated with
the Control Leakage Index Data Easily (CLIDE) software program.
What CLI calculation(s) does the CLIDE software perform?
Both I∞ and I3,000 calculations.
The Control Leakage Index Data Easily (CLIDE) and Leakage
Evaluation System (LES) software programs produce a variety of
reports and forms to analyze signal leakage. Which of the following
are generated from both the CLIDE and LES software programs?
A cumulative leakage index (CLI) report.
The cumulative leakage index (CLI) figure of merit is an estimate
of the leakage field above the system, derived from the ground-
based cable signal leakage measurement information. For I∞
calculations, a passing CLI figure of merit must be what?
Less than 64.
The Leakage Evaluation System (LES version 5.x) program for Windows
generates a cumulative leakage index (CLI) report that includes
test dates, the calculation method used, mileage data, and a
breakdown of leaks by size and repair. What other information
does this report list?
Estimated total system leaks and estimated total hours for
testing.
Cable signal leakage technical standards and other Federal
Communications Commission (FCC) requirements for broadband
cable systems are described in Part 76 of the Code of Federal
Regulations, Title 47, Telecommunications. According to these
regulations, what must every cable television (CATV) system do?
Conduct an annual cumulative leakage index (CLI) or flyover
measurement.
The Federal Communications Commission (FCC) leakage log
requirement can be met with the Leakage Evaluation System (LES)
leakage log summary report. Along with the date, temperature,
technician identification, and location of each leak identified,
what other information does the leakage log report contain?
The probable cause code.
There are various Leakage Evaluation System (LES) reports that
can be used to manage signal leakage information. What LES
report is helpful in determining the preventive measures that
reduce the most leaks (for example, better training or change of
installation procedures)?
The leakage analysis report.
In addition to Leakage Evaluation System (LES) reports that
manage signal leakage information, there are also reports that
document a technician’s involvement with signal leaks. Which of
the following LES reports is the technician’s daily schedule?
The repair work order (RWO) report.
The Wavetracker system with GPS antenna produces the signal
leakage level and location map. Which of the following signal
leakage reports are produced by the Wavetracker system along
with the map?
The cumulative leakage index (CLI) and signal leakage
source report.
You want to measure the system response in frequencies that
your broadband system does not currently use. What tool should
you use?
A sweep meter.
You are measuring system performance and the test results are
sent to you via telemetry signal. What test are you performing?
Return sweep.
Which of the following tests requires additional equipment at
the headend?
Return sweep.
The response goal for the sweep response for the amplifiers in your
system uses the equation N/10 + 2 = __ dB. If there are five amplifiers
at the point of measurement, and four channels are not being used,
what is the maximum peak-to-valley (P/V) measurement?
2.5
Unity gain keeps the signals within the broadband system within
a specific range. Coax equalizers help maintain the signals within
this range. What is the relationship between cable loss and
frequency?
Cable loss varies as a function of the square root of
frequency.
You are using the sweep meter at an amplifier. The sweep response
is flat, but not at the reference level. What should you do?
Cable loss varies as a function of the square root of
frequency.
You are using the sweep meter at an amplifier. The sweep response
is flat, but not at the reference level. What should you do?
Change the pads.
What is the proper way to avoid ingress signals when sweeping a
system during an upgrade?
Set the return pads to high values or terminations.
You are performing a system sweep and the display shows a low
end roll-off. What should you do?
Look for a loose seizure screw, a bad tap face plate, or water
in the tap.
You are testing the sweep at an amplifier input. What would you
expect to find?
) A downward tilt much lower than the 0 dB reference.
You want to measure the system response in frequencies that
your broadband system does not currently use. What tool should
you use?
A sweep meter.
You are measuring system performance and the test results are
sent to you via telemetry signal. What test are you performing?
Return sweep.
Which of the following tests requires additional equipment at
the headend?
Return sweep.
The response goal for the sweep response for the amplifiers in your
system uses the equation N/10 + 2 = __ dB. If there are five amplifiers
at the point of measurement, and four channels are not being used,
what is the maximum peak-to-valley (P/V) measurement?
2.5
Unity gain keeps the signals within the broadband system within
a specific range. Coax equalizers help maintain the signals within
this range. What is the relationship between cable loss and
frequency?
Cable loss varies as a function of the square root of
frequency.
You are using the sweep meter at an amplifier. The sweep response
is flat, but not at the reference level. What should you do?


frequency?
Change the pads.
What is the proper way to avoid ingress signals when sweeping a
system during an upgrade?
Set the return pads to high values or terminations.
You are performing a system sweep and the display shows a low
end roll-off. What should you do?
Look for a loose seizure screw, a bad tap face plate, or water
in the tap.
You are testing the sweep at an amplifier input. What would you
expect to find?
A downward tilt much lower than the 0 dB reference.
You are sweeping a system and the display shows a series of
ripples. What is the most likely cause?
An impedance mismatch.
The FCC requires that the audio carrier center frequency test be
performed
At the headend and at the output of a set-top box.
What is the total carrier-to-composite noise ratio at the output
of a set-top box when the system CCN is 46 dB, the STB noise
figure is 7 dB, and the input carrier level to the STB is 3 dBmV?
–45.6 dBc
The requirement that the peak-to-peak variation in a video signal
level caused by undesired low frequency disturbances generated
within the system shall not exceed 3% of the video carrier signal
level is the FCC standard for
Hum.
In the NCTA recommended equipment setup for testing a non-
volume control RF set-top box for measuring CSO/CTB values, the
device that removes the tested channel from the forward channel
bandwidth is the
Channel delete filter.
When using a spectrum analyzer to manually perform the audio
carrier center frequency test, measure the difference between one
marker on the peak of the audio carrier and another marker
On the peak of the video carrier.
When using a spectrum analyzer to manually perform the carrier-
to-composite noise test
The video carrier modulation must be turned off.
What is the corrected CCN value when: (1) the uncorrected
measured CCN value is –68 dB; (2) the resolution bandwidth
correction factor is 19.03 dB; (3) the log detect Rayleigh noise
factor is 2.50 dB; (4) the IF noise equivalent bandwidth is 1.10 dB;
and (5) the noise-near-noise correction factor is 0 dB?
–45.37 dB
What is the percentage of hum when a spectrum analyzer is used
to manually measure individual channel hum and: (1) each minor
graticule division represents 2.5% of the signal amplitude; (2) the
sweep rate is 5 milliseconds per division; and (3) the peak signal
amplitude varies 1.5 minor graticule divisions between vertical
intervals?
3.75%
When using a spectrum analyzer to manually perform the cross-
modulation test, measure the difference between one marker at
the top of the cross-modulation beat and another marker
At the peak of the video carrier.
Which of the following is not true about the in-channel frequency response test?
It measures the beats that fall at ±0.75 MHz and ±1.25 MHz
from the video carrier.
The boom on a chain trencher
Is usually spring-loaded to create tension on the chain.
A chain trencher
Should be inspected for any loose bolts, broken chain teeth,
or any types of fluid leaks before beginning its operation.
When digging the trench,
The first thing to be done is to contact all of the
utilities for the location of their lines or contact a
state one-call system.
The removal of a very large rock from the ground during
trenching may require a
Backhoe.
Which of the following is not a true statement?
The flooding compound on coaxial cable reduces friction
when pulling the cable through a conduit.
When directly burying coaxial cable,
Avoid reverse bending of the coaxial cable when unreeling
the coaxial cable.
How much contraction will 1,200 feet of conduit have if the
temperature changes from 94 degrees F to 54 degrees F when
the rate of contraction is 1 1/2 inches per 100 feet per
20 degrees F change?
36 inches.
A portable conduit fishing system
Is used to blow a pull-line through the conduit.
Some of the factors in determining the total length of
preassembled cable in a conduit for a trench site are
Thermal expansion/contraction allowance.
When backfilling the trench,
Gravel, a soil stabilizer, or a slurry mixture should be
used when proper compaction is difficult to obtain with the
present trench material.
The self-contained vibratory plow
In most cases is a nonriding unit that can bury the coaxial
feeder cable or conduit 18 inches underground.
Which of the following statements is not true for plowing
coaxial cable?
After reaching the target location, remove the transmitter,
and attach the cable to be pulled.
Which piece of equipment can be used to enlarge the
original size of the bored hole?
Back-reamer.
A pit boring machine
Must be at the same level as the bore path.
During the operation of a fluid-assisted boring system,
If there is an inadvertent utility strike, always follow
your company's and the manufacturer's guidelines and
safety procedures.
 *
When plowing conduit into the ground,
Attach a continuous length of polyethylene conduit to the
plow blade with a pulling grip.
The electrical grid mats for a fluid-assisted boring
system
Keep the operator(s) at the same potential as the boring
equipment.
When operating the fluid-assisted boring system,
Always connect the electrical strike warning system per the
manufacturer's instruction
Which of the following statements is true?
Avoid violating minimum clearances with other buried
utilities, especially electrical power lines.
Vibratory plows
Can pull the coaxial cable into the ground from a cable reel
as the plow cuts through the ground between the pedestal
sites.