Spectrum Field Technician 1
Test
Decibel (dB) - -Relative # of signal gain or loss through a device or cable.
-Decibel millivolt (dBmV) - -Absolute # of signal strength.
-Foreign voltage detector (FVD) - -Detects unwanted voltage on
cables/strands; test on plastics too.
-Data Over Cable Service Interface Specification (DOCSIS) - -The
international standard for adding high-bandwidth data to an existing cable
system.
-What does SAFE stand for? - -Stop. Assess. Focus. Eliminate.
-What does NCP stand for? - -Next. Channel. Pointer.
-What does SLM stand for? - -Signal. Level. Meter.
-What is a signal level meter? - -Tool used to run multiple tests involving
signal level, MER, BER and noise level.
-What does CNR stand for? - -Carrier to Noise Ratio.
-What is the purpose of CNR? - -Comparing level of desired signal to level of
background noise.
-What is Hum modulation? - -The distortion of both cable video and audio.
-How can you identify video hum? - -Visually seeing single (60Hz) or double
(120Hz) horizontal bars rolling slowly up from bottom to top of television.
-How can you identify audio hum? - -By physically hearing a buzzing sound.
-what does BER stand for and what does it do? - -Bit. Error. Ratio.
Overall measure of data quality of the received bit stream.
-Consequences of BER (2 things). - -1.) Video: picture fails
2.) Data: loss of dial tone
-What is the max length of a ground wire? - -20 feet (want the wire as short
as possible).
, -What causes high BER (3 things)? - -1.) Ingress: poor connections
2.) Distortion: undesired change in electrical signal
3.) Noise: unwanted disturbance to a desired signal
-What is the desired BER level? - -1.0E-9
-What does MER stand for? - -Modulation. Error. Ratio.
-How many channels can go into a QAM? - -8-12.
-What do QPSK, 16QAM, 64QAM and 256 QAM have in common? - -They are
phase shifted 90 degrees apart.
-What is Egress? - -Crap coming out of our system.
-What is Ingress? - -Crap coming into our system.
-What does DOCSIS do? - -Permits high-bandwidth data transfer to a cable
TV system.
-What does CPE stand for? - -Customer. Premises. Equipment.
-What does CMTS stand for? - -Cable. Modem. Termination. System.
-What does CMTS do? - -Exchanges digital signals with cable modems on a
cable network.
-What does TDR stand for? - -Time. Domain. Reflectometer.
-What can a TDR test identify (4 things)? - -1.) Total length of cable
2.) Route of the cable
3.) Location of water/moisture in cable
4.) Crushed, pinched or kinked links
-What does LTE stand for? - -Long. Term. Evolution.
-What is LTE? - -Broadband communication for mobile devices/data
terminals.
-What is the equation for calculating current? - -I=E/R
-What is the equation for calculating resistance? - -R=E/I
-What is the equation for calculating voltage? - -E=I*R
Test
Decibel (dB) - -Relative # of signal gain or loss through a device or cable.
-Decibel millivolt (dBmV) - -Absolute # of signal strength.
-Foreign voltage detector (FVD) - -Detects unwanted voltage on
cables/strands; test on plastics too.
-Data Over Cable Service Interface Specification (DOCSIS) - -The
international standard for adding high-bandwidth data to an existing cable
system.
-What does SAFE stand for? - -Stop. Assess. Focus. Eliminate.
-What does NCP stand for? - -Next. Channel. Pointer.
-What does SLM stand for? - -Signal. Level. Meter.
-What is a signal level meter? - -Tool used to run multiple tests involving
signal level, MER, BER and noise level.
-What does CNR stand for? - -Carrier to Noise Ratio.
-What is the purpose of CNR? - -Comparing level of desired signal to level of
background noise.
-What is Hum modulation? - -The distortion of both cable video and audio.
-How can you identify video hum? - -Visually seeing single (60Hz) or double
(120Hz) horizontal bars rolling slowly up from bottom to top of television.
-How can you identify audio hum? - -By physically hearing a buzzing sound.
-what does BER stand for and what does it do? - -Bit. Error. Ratio.
Overall measure of data quality of the received bit stream.
-Consequences of BER (2 things). - -1.) Video: picture fails
2.) Data: loss of dial tone
-What is the max length of a ground wire? - -20 feet (want the wire as short
as possible).
, -What causes high BER (3 things)? - -1.) Ingress: poor connections
2.) Distortion: undesired change in electrical signal
3.) Noise: unwanted disturbance to a desired signal
-What is the desired BER level? - -1.0E-9
-What does MER stand for? - -Modulation. Error. Ratio.
-How many channels can go into a QAM? - -8-12.
-What do QPSK, 16QAM, 64QAM and 256 QAM have in common? - -They are
phase shifted 90 degrees apart.
-What is Egress? - -Crap coming out of our system.
-What is Ingress? - -Crap coming into our system.
-What does DOCSIS do? - -Permits high-bandwidth data transfer to a cable
TV system.
-What does CPE stand for? - -Customer. Premises. Equipment.
-What does CMTS stand for? - -Cable. Modem. Termination. System.
-What does CMTS do? - -Exchanges digital signals with cable modems on a
cable network.
-What does TDR stand for? - -Time. Domain. Reflectometer.
-What can a TDR test identify (4 things)? - -1.) Total length of cable
2.) Route of the cable
3.) Location of water/moisture in cable
4.) Crushed, pinched or kinked links
-What does LTE stand for? - -Long. Term. Evolution.
-What is LTE? - -Broadband communication for mobile devices/data
terminals.
-What is the equation for calculating current? - -I=E/R
-What is the equation for calculating resistance? - -R=E/I
-What is the equation for calculating voltage? - -E=I*R
