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Definition
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What is definition of CLI
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Definition
| A mathematical value derived from the number and severity of leaks in the cable. |
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| Compliance with FCC regulations requires a CLI figure of merit of __ or less. |
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Carrier-to-beat ratios greater than
__ dB are far enough below desired carries levels to be a little concern to the average viewer. |
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| Following ghost appears to the______ of the picture. |
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Definition
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| Leading ghost appears to the _____ of the picture. |
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Definition
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| Following Ghost is caused by what? |
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Definition
| Signal Reflection, Impedance Mismatch |
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| What causes Co-Channel Interference |
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Definition
| When the same channel from two (or more)different TV stations is received by the same antenna. |
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| For Co-Channel Interference to be visible, the difference in levels between desired and undesired channels must be less than __ dB. |
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Definition
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Definition
| Method of reception using a RF current of the proper magnitude and phase relation so the received voltage is of the same nature as the original wave. |
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Definition
| Noise caused by changes in temperature |
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| What is our standard temperature of reference. |
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Definition
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| What is Carrier-to-Noise ratio (C/N) |
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Definition
| Difference in dB between carrier level and noise floor. |
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| What is FCC minimum Carrier to Noise Ratio? |
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Definition
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Definition
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Definition
| Undesired changes in the waveform of a signal. (Distort is to alter the original shape of an object, image, sound, waveform or other form of information or representation.) |
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| What is definition of XMOD? |
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Definition
| The crossing of modulation from one channel to another. |
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Term
| Since horizontal sync pulse has the highest energy content of any of the video components within a TV channel, cross-modulation typically mainfests itself as ? |
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Definition
| Vertical bar and ghost images. |
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| Composite Third Order(CTB) does not effect which 2 channels? |
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Definition
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Definition
| Composite Triple Beat or Composite Third Order (Book shows 2 different answers)((CTB is the ratio of carrier to Composite Third order Beat, also called Composite Triple Beat.) |
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| For each dB the levels of a well behaved amplifier are raised, the carrier CTB ratio gets __ dB worse. |
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Definition
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Definition
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Definition
| Appears as a horizontal bar in the picture. Primary source is the power passing chokes used in passive devices. |
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| Minimum carrier to hum ratio |
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Definition
| 30 dB or better (less than or equal to 3% hum) |
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Term
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Definition
| Quadrature Amplitude Modulation |
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Definition
| Quadrature Phased Shift Keying |
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Definition
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Definition
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Definition
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Definition
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Definition
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Definition
| Radio Frequency (Forward and Return Signal Strength) |
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| Forward Spectrum Begins at ___Mhz and can be as high as ___Ghz |
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Definition
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| Return spectrum starts from __Mhz to __Mhz |
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Definition
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Term
| How many phase states with a QPSK carrier |
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Definition
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Term
| Signal-to-noise Ratio is? |
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Definition
| A measure of signal strength relative to background noise in analog and digital communications. |
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Term
| Define MER(Modulation Error Correction) |
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Definition
| Measures the ratio of the error power to the average power in an ideal QAM signal. Comparable to the SNR measurement in analog systems. |
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| Define FEC (Forward Error Correction) |
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Definition
| Is a method where additional data bits are added to the digital video bit stream to help identify and correct any errors that may be caused by the transmission system |
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Term
| Define BER (Bit Error Rate) |
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Definition
| Meaures how often an error occurs in a given amount of data |
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Definition
| A condition where interfering signals leak into a cable network. |
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| Devices used to terminate RF signals. This maintains the system inpedance, which reduces signal reflections. |
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Definition
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Term
| What is the primary source of hum modulation today? |
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Definition
| Power passing chokes used in passive devices. |
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Term
| What device in the power inserter prevents RF energy from entering into the power supply? |
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Definition
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Term
| What is the purpose of a power inserter? |
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Definition
| Introduce AC power into the network for use by the active devices. |
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Term
| Which Comcast network architecture provides a single, common infrastructures in which all services are delivered via IP over a consistent transport and routing architecture. |
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Definition
| CRAN (Converged Regional Area Network) |
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Term
| What are the leakage limits? |
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Definition
| Over 54 MHz up to and including 216 MHz – 20 micro-volts per meter, measured at 3 meters |
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Term
| A leakage test can be conducted in what two ways? |
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Definition
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Term
| What causes a leading ghost? |
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Definition
| When ingress allows a locally broadcast TV channel's signal to enter TV along with channel's supplied by network. |
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| Majority of ingress enters the system between the ___ and the customer's TV set. |
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Definition
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| Discrete 2nd order, the 2nd harmonic is ___dB lower then the carrier. |
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Definition
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Term
| TV carriers are spaced at ____ increments. |
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Definition
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Term
| Excessive DC current draw, would result in 120-cycle modulation of the TV carriers. This would cause___ hum bars to appear in the picture. |
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Definition
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Term
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Definition
| Is the process of varying one or more properties of a high-frequency periodic waveform, called the carrier signal, with respect to a modulating signal. |
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Term
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Definition
| Digital modulation scheme that allows 2 channels of information to be transmitted at the same time on a particular frequency by changing the phase and amplitude. |
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| With Ingress, anything higher than ___dbmV is a problem that you need to investigate. |
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Definition
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Term
| You must disconnect the drop from the cable system before you use any tone/signal generating device? True or False |
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Definition
| True. Tone Generators send strong interfering carriers back into the cable system. |
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Term
| What does a high pass filter do? |
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Definition
| It passes high frequencies well, but attenuates frequencies lower than the cut-off frequency. (Comcast high pass filter attenuates 3-50MHz) |
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Term
| Total system noise combines as it travels towards the headend and is called? |
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Definition
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Definition
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Term
| Basic Troubleshooting Steps is also known as an ______ _____? |
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Definition
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Term
| Whats does FDM stand for? |
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Definition
| Frequency Division Multiplexing |
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Term
| What is the definition of FDM (Frequency division multiplexing) |
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Definition
| The ability to carry and individually select different channels on a single cable by their unique frequency. |
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Term
| A power diplex does what? |
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Definition
| Separates or combines the AC current's two parts: the AC power and the RF broadband signals. |
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Term
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Definition
| Using a single circuit or transmission link for the simultaneous transmission or reception of two signals |
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| Diplex Filters does what? |
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Definition
| Separates the forward and reverse signals from the coax so they can be routed to (and from) the appropriate components within the amplifier. |
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Definition
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Definition
| Compensates for the unequal attenuation properties of coax at different frequency. (Input EQ flattens the signal) |
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| Forward Amplifier Module(Trunk amp)does what? |
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Definition
| Amplifies forward signals passing through the trunk and distribution lines. |
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Term
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Definition
| Sometimes called a Mop-up, tries to correct any undesired peaks or valleys within the passband of the amplifier |
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Term
| What is Automatic Gain Control (AGC) |
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Definition
| Used to compensate for fluctuations of the input signal. |
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Term
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Definition
| Amplifies forward signal and sends it out to feeder line (as many as 4) |
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Definition
| Used to boost return signals. |
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Definition
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Definition
| Lowers low-frequency to correct reverse tilt. |
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Term
| What does in-line conditioners help? |
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Definition
| Upstream. Uses attenuators pads to increase upstream levels. |
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Term
| What does a power inserter introduce to the cable system? |
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Definition
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Term
| 4 parts of a coaxial cable? |
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Definition
| Jacket, conductor(sheath), dielectric, center conductor |
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Term
| 3 parts of a fiber cable. |
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Definition
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Term
| What is a optical transmitter do? |
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Definition
| Changes the RF signal into pulses of light and then transmits them onto the optical fiber. |
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Term
| What does a optical receiver do? |
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Definition
| Converts incoming light to RF signals. |
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Term
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Definition
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Term
| Wavelength is a measurement of _____, the ____ that signal of a specific frequency travels during the time it takes to complete one full cycle. |
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Definition
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Term
| The wavelengths of light used in broadband telecommunications are centered at ____ nm and _____nm. |
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Definition
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Term
| What does CRAN stand for? |
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Definition
| Converged Regional Area Network. |
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Term
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Definition
| Only known and trusted routes exist or are propagated from one part of Comcast network to another. |
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Term
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Definition
| Comcast Private Backbone or Converged Backbone |
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Term
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Definition
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Term
| How much straight cable do you start with when starting your splice? |
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Definition
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Term
| What distance do you mark the cable where you want the tool to stop. |
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Definition
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Term
| With XMOD, if the bars fall of screen, cross modulation should be __dB below the visual carrier level for non-visibility of the offending video. |
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Definition
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Term
| With XMOD, if on screen, carrier to cross modulation should be ____dB. |
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Definition
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Term
| What becomes visible before a XMOD in a systems carrying more than forty or more channels. |
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Definition
| (CTB) Composite Triple Beat (CTB is the ratio of carrier to Composite Third order Beat, also called Composite Triple Beat.) |
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Term
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Definition
| Caused by anything with a motor. Electrical Noise |
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Definition
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| Minimum aerial clearance for drops above public streets, alleys, roads, and commercial and residential driveways. |
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Definition
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Definition
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| Grounding wire should not exceed ____feet or the length of the shortest cable outlet. |
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Definition
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Definition
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Term
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Definition
| Uninterruptible Power Supply |
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| The loss for Series 6 at the highest frequency? |
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Definition
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| Number of phase states in a QAM carrier? |
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Definition
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Term
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Definition
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| How long do you keep CLI Logs? |
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Definition
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Term
| What are the five types of system maps |
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Definition
| Base Map, Strand Map, Design Map, Amplifier Schematic or "Tree" Map, and As Built Map. |
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Term
| Map that resembles street map, complete with feature like lakes and rivers, streets, and boundaries. |
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Definition
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Term
| Shows streets with poles and pedestal locations and includes the span length or footage between these items. |
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Definition
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| Shows the location of the electronic equipment, including the headend and any hubs, also amps, power supplies, and taps. |
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Definition
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| Maps provide the layout of the system in a condensed form. |
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Definition
| Amplifier Schematics or "tree" maps |
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| Word to help remember types of maps? |
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Definition
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