NAVEDTRA 14189A, Ch. 2

Question 1

What is the principle use of the continuous wave?

Answer 1

Radiotelegraphy

Question 2

A cw transmitter requires four essential components. These are a generator, amplifier, keyer, and what else?

Answer 2

Antenna

Question 3

What is power the product of?

Answer 3

Current and Voltage

Question 4

What refers to a sine wave quantity (for example, an oscillator output) that has a frequency that is a submultiple of the frequency of some other sine wave quantity it helped make?

Answer 4

Subharmonic

Question 5

What are special power amplifiers that multiply the input frequency?

Answer 5

Frequency multipliers

Question 6

What is the elimination of the undesired portions of the signal?

Answer 6

Suppression

Question 7

What type of transmission is the most common communications mode used today?

Answer 7

Single-sideband

Question 8

What is generally used whenever special voice communications circuits are necessary between shore activities or between ships and shore activities because it is less susceptible to atmospheric interference than amplitude modulation?

Answer 8

SSB

Question 9

What is used extensively in naval communications to expand our traffic capabilities?

Answer 9

ISB

Question 10

What four basic functions must a receiver perform in order to be useful?

Answer 10

Reception, selection, detection, and reproduction

Question 11

What occurs when a transmitted electromagnetic wave passes through the receiver antenna and induces a voltage in the antenna?

Answer 11

Reception

Question 12

What is the ability of the receiver to select a particular frequency of a station from all other station frequencies appearing at the antenna of the receiver?

Answer 12

Selection

Question 13

What is the action of separating the low (audio) frequency intelligence from the high (radio) frequency carrier?

Answer 13

Detection

Question 14

What is the action of converting the electrical signals to sound waves?

Answer 14

Reproduction

Question 15

What property is defined by the ability of a receiver to reproduce weak signals?

Answer 15

Sensitivity

Question 16

What is the limiting factor of sensitivity?

Answer 16

Noise

Question 17

What is the degree of distinction made by the receiver between the desired signal and unwanted signals?

Answer 17

Selectivity

Question 18

What property of a receiver is its ability to accurately reproduce, in its output, the signal that appears at its input?

Answer 18

Fidelity

Question 19

What is the process used to tune two or more circuits with a single control?

Answer 19

Ganged tuning

Question 20

What are the only two fundamental sections of the FM receiver that are electrically different from the AM receiver?

Answer 20

Discriminator and Limiter

Question 21

Which circuit in FM circuits is designed to respond to frequency shift variations?

Answer 21

Discriminator

Question 22

What is the variation in signal strength called at the receiver antenna?

Answer 22

Fading

Question 23

What is an AGC voltage that is used to cause degeneration by driving the amplifiers toward cutoff referred to as?

Answer 23

Reverse AGC

Question 24

Which audio amplifier property determines the degree of amplification provided to different frequencies in the sound spectrum?

Answer 24

Frequency response

Question 25

Treble tones are defined as the audio frequencies above approximately what frequency?

Answer 25

3,000 hertz

Question 26

Bass tones are defined as the audio frequencies below approximately what frequency?

Answer 26

300 hertz

Question 27

Which circuits are used in situations where you must accurately control the frequency of an oscillator by some external signal?

Answer 27

Automatic Frequency Control

Question 28

Which circuit cuts off the output of a receiver when there is no input?

Answer 28

Squelch

Question 29

What is a signal-producing process through heterodyning and frequency selection?

Answer 29

Frequency synthesis