nct4 v2 Flashcards Preview

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Flashcards in nct4 v2 Deck (500)
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1

Random electron activity in the atoms that make up the conductor

Thermal Noise

2

Noise floor in a 4MHz bandwidth @ 68*F is called:

Termination Noise

3

Difference in a peak carrier level to the noise floor:

Carrier to Noise

4

Amount of noise in a 4MHz bandwidth on a 75 Ohm cable @ 68*F

-59.16dB

5

FCC Spec for C/N

43dB

6

Undesired change in the waveform of a signal

distorion

7

Crossing of Modulation from one channel to another

XMOD or Cross Modulation

8

XMOD appears as

Vertical bars in the picture

9

2nd harmonics of any 2 channels are typically _____ below the sum/difference products

6dB

10

CTB products fall within _____ of the video carrier

30 KHz

11

Tilting the output of an amplifier improves:

Distortion performance

12

CSO beats fall @ __________ above the video carrier

1.25MHz +/- 15 KHz

13

unwanted sum/difference frequencies resulting from heterodyning of 2 or more signals

Beats

14

A horizontal bar in the picture is _______ Modulation

Hum

15

Primary cause of Hum (60Hz)

Power Passing Choke (60Hz)

16

A source of hum in older systems (120Hz)

Series regulated DC Power supplies (120Hz)

17

3 parts of fiber

Coating, Cladding, Core

18

When light stays in the core, this is called

Total Internal Reflection

19

2 wavelengths used in HFC Networks

1550nm & 1310nm

20

Most common type of fiber used in the cable industry

Single Mode Fiber

21

Wavelength is ________ proportional to frequency

Inversely

22

A shorter wavelength means a _______ Frequency

Higher

23

Compares the speed of refracted light in a material to the speed of light in a vacuum

Index of Refraction

24

One Billionth of a meter

nanometer

25

Device that takes the RF and modulates it onto an optical wavelength

Optical Transmitter

26

Optical transmitters use this type of diode

Laser Diode

27

What device detects light and demodulates it to RF

Optical Receiver

28

An optical receiver uses this type of Diode

Photo Diode

29

C/N Formula

L1-(NF-59.2)

30

Formula for C/N @ end of cascade

C/N1-10logN (C/N1 is equal to the C/N of a single amplifier in the cascade, N=Number of amplifiers)

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