Term
| After you have adjusted the oscilloscope intensity control, what other control may you need to adjust? |
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Definition
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Term
| When a halo appears around the spot on an oscilloscope screen, what control should you adjust? |
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Definition
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Term
| When the spot is elliptical on the screen, what control should you adjust? |
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Definition
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Term
| What happens if you increase the vertical gain control too much? |
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Definition
| The display becomes distorted. |
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Term
| What height-to-width ratio provides optimum display proportions for general-purpose waveform examinations? |
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Definition
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Term
| Which controls do you use to center the spot on the screen? |
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Definition
| Vertical and horizontal positioning controls. |
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Term
| What happens if you advance the synchronizing control too far? |
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Definition
| The display becomes distorted. |
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Term
| What are the two major sections of a BERT set that create and receive the test pattern? |
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Definition
| The data code generator and code detector. |
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Term
| What type of test pattern does the data code generator produce? |
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Definition
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Term
| Name two common signal codes that are used with BERT sets. |
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Definition
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Term
| Name two framing formats to use with BERT sets. |
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Definition
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Term
| What does 63, 511 and 2047 in a test pattern identify? |
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Definition
| The total number of bits in the test pattern. |
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Term
| Explain the purpose of a breakout box. |
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Definition
To monitor and access all 25 conductors of EIA RS-232 and ITU V.24 interfaces between data modems and terminals. |
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Term
| What is the purpose of the 24 miniature ON/OFF switches on a breakout box? |
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Definition
To allow all interface conductors (except frame ground pin 1) be interrupted individually for isolated testing and observation. |
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Term
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Definition
A form of distortion involving displacement in time of the transitions in a signal, causing a back-and-forth movement. |
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Term
| At what point in a PCM/TDM system is the timing jitter test taken? |
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Definition
At the input to the second-level digital multiplexer. |
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Term
| What test equipment do you use to measure timing jitter when you use the total peak-to-peak jitter method? |
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Definition
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Term
| If there are 110 divisions for one bit time and the measured jitter is 29 divisions, what is the percent of jitter? |
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Definition
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Term
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Definition
| The ratio of total bits in error to the total bits transmitted. |
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Term
Which test determines the overall performance of a digital link? |
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Definition
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Term
| What must you do before connecting a BERT set to a channel? |
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Definition
Loop the transmit output back to the receive equipment to make sure the receiver synchronizes. |
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Term
| Explain what an "average bit error rate per run" means. |
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Definition
The number of bit errors measured during the run interval dividend by the total number of bits transmitted during the run. |
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Term
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Definition
A predetermined sequence of logical ones and zeros used for testing during T-1 installation and fault isolation. |
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Term
| Which test pattern was found effective for testing voice-grade circuits? |
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Definition
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Term
| Which test pattern is suited for finding a misoptioned T-3 equipment set for B8ZS operations? |
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Definition
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Term
| Which test pattern should you use first in testing a T-1 circuit? |
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Definition
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Term
| Explain why the 3-in-24 test pattern is unique. |
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Definition
When it's transmitted unframed along unframed circuits, the pattern simultaneously stresses the maximum consecutive zeros and the minimum ones density specifications. When it's transmitted framed and aligned with the framing pattern, it stresses the consecutive zeros requirement, but slightly exceeds ones density criteria. When it's transmitted framed, but not aligned to the frame patter, it often creates a D4 yellow alarm condition. |
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Term
| To stress the minimum ones density of a circuit using B8ZS coding, which test pattern would you use? |
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Definition
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Term
Description of Digital Test: Two types-controlled and uncontrolled. |
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Definition
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Term
Digital Test Description: The unit of measure is dBdsx. |
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Definition
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Term
Digital Test Description: May cause automatic switching to spare equipment. |
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Definition
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Term
Digital Test Description: Generated by equipment when no signal is received. |
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Definition
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Term
Digital Test Description: The test to perform to ensure that your T-1 system is operating at 1.544 MHz. |
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Definition
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Term
Digital Test Description: Should be less than 21 errors in 45 minutes for superframe circuits. |
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Definition
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Term
| List the four main causes of T-1 impairments. |
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Definition
1.) Faulty equipment 2.) Data specific 3.) Environmental factors 4.) Improper connections |
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Term
| What is the minimum distance a medium-speed digital circuit cable pair should be separated from other medium-speed digital circuits? |
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Definition
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Term
| List three effects of an impedence mismatch. |
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Definition
(1) Poor frequency response. (2) Excessive loss of signal power. (3) Improper level measurements. |
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Term
| At the sending station, what should the output impedence of the signal generator be? |
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Definition
The same as the input impedance of the channel being tested. |
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Term
| What is the input terminal impedence of a circuit that has a terminal voltage of 0.25 volt and an open circuit voltage of 0.5 volt? |
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Definition
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