NCTI Service Technician Exam With
100% Correct Answers 2023
What are three principle characteristics that define an AC waveform? - Correct Answer-
The three principle characteristics that define an AC waveform are: (1) frequency; (2)
wavelength; and (3) amplitude.
What is one of the basic principles of resistance reflected in the familiar practices of
grounding and bonding? - Correct Answer-Grounding and bonding practices reflect the
basic principle that electricity always follows the path of least resistance.
What comprises the impedance of a coaxial cable or a device (connector, passive,
etc.)? - Correct Answer-The impedance comprises the combined effects of a coaxial
cable's or a device's resistance, inductance, and capacitance.
What is a high pass filter? - Correct Answer-A high-pass filter is a type of bandpass filter
that passes all frequencies above a specific frequency (e.g., 50 MHz), and eliminates
common path distortions, impulse noise in the return spectrum, and any other
frequencies that fall below that specific frequency.
What are the differing forward-path transmission bandwidths for traditional tree-and-
branch and HFC architectures? - Correct Answer-The feeder system in a traditional
tree-and-branch architecture supplies the forward signal up to a 50-550 MHz pass band,
and the distribution system in an HFC network transmits the forward signal up to a 50-
1,000 MHz pass band.
Where does the feeder system forward path start and end in a tree-and-branch design?
- Correct Answer-A tree-and-branch feeder system forward path starts at the output of
the bridger amplifier module in the trunk/bridger amplifier station and ends at the tap
port of an RF tap.
Where does the distribution system forward path begin and end in an HFC design? -
Correct Answer-An HFC distribution system forward path begins at the output of an RF
amplifier located in the optical node and ends at the tap port of an RF tap.
What is the purpose of a coaxial express cable in an HFC distribution system? - Correct
Answer-A coaxial express cable allows a particular optical node to reach farther out in
the distribution system.
How is underground cable manufactured? - Correct Answer-Underground cable is
manufactured with a protective outer jacket covering the aluminum sheath and flooding
compound between the jacket and the sheath.
,How do frequency and cable size affect the attenuation of a broadband signal? - Correct
Answer-The attenuation of a broadband signal increases with higher frequencies and
decreases with larger cable size.
What is the role of splitters and directional couplers in the forward and return paths? -
Correct Answer-Splitters and directional couplers divide and route the forward RF signal
transmission throughout the distribution system, and combine return-path signals
arriving from separate feeder runs.
How is AC power transmitted in an RF tap? - Correct Answer-AC power passes
bidirectionally through the tap, but is prevented from passing through to the tap ports
except by design in power-distributing taps.
What is the distinction between a line extender amplifier and a distribution amplifier? -
Correct Answer-The distinction is a line extender, which has a single output port and a
distribution amplifier, or minibridger, which has multiple output ports (typically three
ports; a through-port and two auxiliary output ports).
What are five important components of an amplifier station? - Correct Answer-Five
important amplifier station components are: (1) input and output diplex filters that
separate and combine the forward and return paths within the amplifier; (2) forward and
return plug-in pads and equalizers for controlling the input signal levels; (3) an RF
amplifier module; (4) an integrated or stand-alone DC power supply with DC current
fusing; and (5) AC power direction control.
What factors define the extent of a power realm? - Correct Answer-Cable resistance,
combined amplifier load requirements, individual amplifier voltage minimums, and limits
on AC current define the extent of power realms.
What are the three main components of a typical standby power supply? - Correct
Answer-The three main components of a standby power supply are: (1) a ferroresonant
transformer that supplies the output voltage; (2) a set of batteries acting as a backup
power source; and (3) an AC inverter that converts the DC battery backup power to a 60
or 90 VAC output.
What does a signal level meter (SLM) measure? - Correct Answer-An SLM measures
individual analog video and audio, and digital carrier levels.
What does a digital multimeter (DMM) measure? - Correct Answer-A digital multimeter
(or VOM) measures AC and DC voltages, resistance for continuity checks, and current.
What does a time domain reflectometer (TDR) measure? - Correct Answer-A TDR
measures the presence of and distance to cable faults.
What does a signal leakage detector measure? - Correct Answer-A signal leakage
detector is an RF receiver with an installed input antenna that measures broadband
,cable signals leaking from the system within FCC assigned aeronautical frequency
bands.
What does a combination SLM/leakage detector measure? - Correct Answer-A
combination SLM/leakage detector incorporates the features of both an SLM and a
signal leakage detector.
What are measurement applications for using SLMs, DMMs, TDRs, leakage detectors,
and combination leakage detectors? - Correct Answer-The measurement applications
include: (1) balancing amplifier (bridger, distribution, and line extender) output levels
(SLM); (2) verifying system and amplifier power supply operation (DMM); (3) identifying
cut or damaged cable spans (TDR); (4) identifying sources of ingress (signal leakage
detector, SLM); and (5) monitoring and measuring signal leakage (egress) for system
CLI reporting (combination SLM/leakage detector).
What is the proper troubleshooting technique? - Correct Answer-Begin at a location
common to all known outage sites, divide the area of unknown signal status in half,
verify the signal condition, and repeat (if necessary) until the source of the problem is
found.
How can a distribution system design map aid the troubleshooting process, after
gathering as much information as possible about the extent of the affected area? -
Correct Answer-A system design map is used to analyze system for the device common
to the customers so far affected before traveling to make additional signal status
checks.
What are six sources of outages caused by powering failures? - Correct Answer-
Powering failures include: (1) a utility power failure; (2) a tripped utility breaker; (3) spent
standby battery power; (4) a blown distribution leg fuse; (5) a blown amplifier DC power
supply fuse; and (6) a cable center conductor suck-out.
What are three groups of outage causes associated with cut or damaged cables? -
Correct Answer-The outage groups are: (1) cables cut by underground digging
equipment (a backhoe, a trencher, a post-hole digger, a shovel, etc); (2) aerial cable
damaged by lightning or downed power lines; and (3) downed aerial cable due to traffic
accidents or severe weather.
How often are outages caused by equipment failures? - Correct Answer-Outages
caused by equipment failures generally occur less frequently than other outage
categories.
What tasks are involved in maintaining physical plant integrity within the distribution
system? - Correct Answer-Maintaining physical plant integrity involves: (1) checking and
tightening loose connectors, housing enclosures, and tap face plates; (2) lubricating
pedestal and power supply padlocks periodically during normal access; and (3) securing
and documenting any broken lashing wire to prevent further deterioration.
, What does eliminating a discovered signal leak accomplish? - Correct Answer-
Eliminating a discovered leak averts a potential outage or trouble call.
What are six performance checks involved in maintaining power supplies? - Correct
Answer-Power supply performance checks include: (1) AC input voltage; (2) AC output
voltage; (3) output current (amperage) draw; (4) individual battery voltages; (5) charging
(float) voltages; and (6) standby switching capability.
When does alternating current change direction in the conductor? - Correct Answer-
Alternating current changes direction (or alternates) in the conductor each time the
potential difference applied to the ends of the conductor changes (or alternates) its
polarity.
Define an AC power source. - Correct Answer-An AC power source is a potential
difference in a circuit that continually changes its polarity.
What term is used more commonly than "alternator" to describe an AC power source? -
Correct Answer-AC generator" is the term used more commonly than "alternator" to
describe an AC power source.
What does an AC generator produce using magnetism and mechanical motion? -
Correct Answer-An AC generator produces AC voltage using magnetism and
mechanical motion.
Define "flux lines." - Correct Answer-"Flux lines" are magnetic lines of force running
longitudinally from the north pole to the south pole of a magnet.
What is the left-hand rule? - Correct Answer-The left-hand rule states that when the
index finger points in the direction of the magnetic field and the thumb points in the
direction that the conductor moves through a magnetic field, the middle finger points in
the direction that the electromotive force causes the current to flow.
Where does the AC voltage appear in an AC generator consisting of a loop of wire
rotated between the poles of a magnet? - Correct Answer-The AC voltage appears
across the gap between the ends of the loop in an AC generator consisting of a loop of
wire rotated between the poles of a magnet.
What is a slip ring in an AC generator consisting of a loop of wire rotated between the
poles of a magnet? - Correct Answer-A slip ring is a smooth circular band of conducting
material connected to one end of the loop, in an AC generator consisting of a loop of
wire rotated between the poles of a magnet.
List three mechanical forces used to turn the armature of AC generators in large-scale
AC power production. - Correct Answer-Flowing water, burning coal to produce steam,