NCTI Service Technician questions with correct answers
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Course
Ncti field tech
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Ncti Field Tech
What are three principle characteristics that define an AC waveform? 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...
NCTI Service Technician questions with
correct answers
What are three principle characteristics that define an AC waveform? 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? 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.)? 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? 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? 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? 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? 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? Answer✓✓ A coaxial express cable allows a particular optical node to reach farther out in the distribution system.
How is underground cable manufactured? 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? 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? 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? 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? 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? 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? 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? 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? Answer ✓✓ An SLM measures individual analog video and audio, and digital carrier levels.
What does a digital multimeter (DMM) measure? 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? Answer ✓✓ A TDR measures the presence of and distance to cable faults.
What does a signal leakage detector measure? 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? 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? 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? 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? 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? 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? Answer✓✓ The outage groups are: (1) cables cut by underground digging
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