Spectrum Field Tech Questions and Answers 100% Pass

Spectrum Field Tech Questions and Answers 100% Pass Current/ amperage Flow or movement of electric charges Resistor a passive two-terminal material that impedes the flow of current What is the most common workplace hazard involving electricity? Electrical shocks What is minimum approach distance? The shortest safe distance to keep from energized conductors CATV at the pole 40'' CATV at the mid-span 24'' CATV at the house 12'' Live parts of electric equipment must be guarded against at how many volts? 50 volts What are the 2 kinds of grounds required by Safety standards for electrical systems? Service and Equipment What are circuit protection devices designed to do? Automatically limit or shift off the flow of electricity in the event of a ground fault, overload, or short circuit in the wiring system OSHA Occupational Safety and Health Administration CATV Community Antenna Television HFC Hybrid Fiber Coax What are the four sources of signals? Satellite, local origination, off air, fiber optics Forward 54 MHz-1 GHz G.B. Guard Band Return 5-42 MHz Downstream (forward path) Forward signal from the headend to a customer Upstream (reverse path) Return signal from a customer to the headend Signal frequency Number of times that an RF signal completes a cycle from a positive value to a negative value and back in one second Ultrasonic frequencies are higher than what? Audio Infrasonic frequencies are below what? Audio How many hertz can the human ear hear? 20-20,000 Per NTSC requirements, what is a tv channels bandwidth? 6MHz FCC (Federal Communications Commission) Gov agency responsible or regulating and assigning frequencies throughout the US HFC distributes what? Broadband signals through a network of various elements Nodes Convert the light signals from the headend into radio frequency signals for delivery to customer Ingress signal leakage TV: Lines in picture, ghosting, pay per view problems, scrambling problems Ingress signal leakage Internet: Lack of internet access, lack of internet access, lack of email services, data problems Ingress signal leakage Voice Telephone call failures (incoming and out coming) QAM (quadrature amplitude modulation) Is both an analog and digital modulation scheme used for transmitting digital data as an analog signal by using a carrier split into 2 carriers of identical frequency phase shifted 90 degrees apart How many programming channels can digital signals have within a 6 MHz space? 12 CLI Cumulative Leakage Index What are charters technical standard for 256 QAM and OFDM carries at CPE? 34 dB or better BER bit error rate Post BER 1.0e-9 Pre BER 1.0e-6 FEC Forward Error Correction SLM Signal Level Meter CNR Carrier to Noise Ratio Hum Modulation The amplitude distortion of broadband cable video and audio carriers by 60 Hz or 120 Hz voltage What are the two types of hum modulation? Video and audio Digital= Rate data bitstream Analog= Concentrated at a single frequency How much bandwidth is required to transmit digital signal data? 6 MHz The wider the digital signal the more? Power Higher BER can be caused by? Ingress Distortion Noise Interference Hum Reflection Spaced errors Errors that are spread out because of noise Burst errors Errors that are grouped together because of intermittent problems such as ingress or loose connectors FEC Generates and introduces additional bits as data is transmitted Uncorrectable FEC errors are caused by: Impulsive noise or ingress interference Loose or intermittent connections A faulty modem MER A measurement used to quantify the performance of communications system transmitting a digital signal Industry acceptable MER values for QPSK ~24dB Industry acceptable MER values for 64-QAM ~27dB Industry acceptable MER values for 256-QAM ~31dB Voltage Measurement of the force or pressure that electrons to move 1v equals what? 1 current of 1 ampere through a resistance of one ohm Current are measured in what? Amperes Resistance The opposition a material offers to the flow of current Power The rate at which work is done. Measured in watts 1 watt= what? 1V X 1AMP ISA Integrated Splitter Amplifiers How many outlets are needed to use ISA? 4 OR more Grounding a conducting connection between an electric circuit or equipment and the earth or some other conducting body. Bonding The permanent joining of metallic ports to form an electrically conductive path that will ensure electrical continuity and the capacity to conduct safely any current likely to be imposed What is the rg6 bond? 12 What is the rg11 bond? 6 What type of bond for mobile home trailer? Mobile home trailer beam clamp Out of band (OOB) Signals sent to and from STB that are not directly related to delivery of the video product. Used for delivery data streams that support STB operation in the forward and to convey responses and commands from the STB in the return What are some examples of OOB? Program guides, channel lineups, and updated operating system code changes Addressability The ability to control STBs from a remote location Switched Digital Video (SDV) A two-way technology that provides charter with a cost-effective way to move efficiently use its bandwidth In-band data path Pathway that delivers video channels from charters headend downstream to each STB Modem modulator-demodulator. Modem modulates outbound signal while at the same time demodulating incoming signal DOCSIS (Data Over Cable Service Interface Specification) International telecommunications standard that allows high-bandwidth data transfer over an existing coaxial cable TV system Internet Wireless standard IEEE 802.11 What is not available when using cable cards? SDV. Customer-owned devices must be connected after the tuning adapter in order to receive SDV