Flashcards in nct 4 signals Deck (91)

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1

## The Cable TV System is also referred to what type of a system?

### A Closed Loop System.

2

## Within what part of the coaxial cable is the radioenergy is designed to be contained within?

### The Shield

3

## The spot of damaged cable where the radio energy escapes into free space, transmitting (egress) and receiving (ingress) signals becomes what?

### An antenna.

4

## When a leakage is discovered, how do we isolate and locate the cause, make repairs, and verify that the leakage has been resolved?

### By using radio receivers tuned to the aeronautical frequency band.

5

## What must every system do to verify that there is no ingress above the power levels specified by the FCC?

### Complete a proof of performance test and submit itsreport to the FCC periodically

6

## What is the difference between a microvolt and a millivolt?

### A Microvolt is unit of electric potential equal to one millionth (10-6) of a volt. A Millivolt (mV) is a unit of potential difference equal to one thousandth (10-3) of a volt.

7

## Logarithm

### Is the exponent or the power to which a fixed number (the base) must be raised in order to produce a given number.

8

## How are Logarithms normally computed?

### To the base of 10 and can therefore be defined as ‘The exponent of 10 required to equal the number.’

9

## What is the log of 100?

### The log of 100 is 2 (10 with an exponent of 2 = 100.)

10

## What are Logs (logarithms) used for?

### Is used for shortening mathematical calculations.

11

## What’s an Exponent?

### Is the number of times the base is multiplied by itself. (Example: 10 to the 2nd power = 100, 2 is the exponent)

12

## What is a Base?

### The number being raised. (Ex: 10 to the 2nd Power = 100, 10 is the base).

13

## Any number raised to the exponent 0 is equal to what?

### 1

14

## Any number raised to the exponent 1 is equal to what?

### Itself

15

## How does one multiply two or more numbers with the same base?

### By adding the exponents.

16

## How does one divide two or more numbers with the same base?

### By subtracting the exponents.

17

## What Prefix is a 10 with an exponent of 9?

### Giga

18

## What Prefix is a 10 with an exponent of 6?

### Mega

19

## What Prefix is a 10 with an exponent of 3?

### Kilo

20

## What Prefix is a 10 with an exponent of -3?

### Milli

21

## What Prefix is a 10 with an exponent of -6?

### Micro

22

## What Prefix is a 10 with an exponent of -9?

### Nano

23

## What Prefix is a 10 with an exponent of -12?

### Pico

24

## if 256 QAM is employed the baud rate is how many bits per second?

### 8

25

## Definition of Hertz

### the System Of Units (SI) unit of frequency, equal to one cycle per second.

26

## What is a continuous signal or carrier that varies in amplitude or frequency as a function of changes at its input?

### An analog signal.

27

## A non-continuous signal or carrier that changes its output in discreetly timed steps of voltage level and/or phase that can represent numerical values or other information.

### Digital Transmission

28

## Name 4 of the 8 advantages that digital transmission has over analog transmission:

### 1) No noise or distortion accumulation.2) High immunity to interference.3) Error checking may be included.4) Can be compressed and/or encoded.5) Easily stored and retrieved.6) Can be multiplexed and multi-layered.7) Unlimited copying or regeneration.8) Little or no loss of quality over long distances.

29

## 2 of the 3 disadvantages of digital transmission are:

### 1) Some loss of quality may occur in the conversion process.2) Added expense of digital processing devices.3) Digital terminal.

30