Navedtra 14189A, Navy Electricity And Electronics Training Series. Module 17-Radio-Frequency Communications Principles 2

Front 1

Frequencies above what are not normally refracted by the atmosphereand ground-wave range is minimal?

Back 1

30 megahertz

Front 2

The naval communications system is broken down into what groups?

Back 2

Strategic and tactical

Front 3

What type of communications are usually limited to a specific area ofoperations and are used to direct or report the movement of specificforces?

Back 3

Tactical

Front 4

What mode is a method of operation in which telecommunicationsbetween stations takes place simultaneously in both directions using twoseparate frequencies?

Back 4

Full-Duplex (fdx)

Front 5

What is the type of operation in which one station transmitsinformation on one or more channels directed to more than one stationand/or unit?

Back 5

Broadcast (bc)

Front 6

Message traffic is normally sent to the fleet by three methods:broadcast, intercept, and what else?

Back 6

Receipt

Front 7

What combines into a single system all the elements that make up thenaval communications system and the Army and Air Force equivalent?

Back 7

DCS

Front 8

What offers rapid, direct interconnection of DOD and certain othergovernment installations through worldwide telephone exchanges?

Back 8

DCS AUTOVON

Front 9

What provides authorized users with a means for exchangingclassified information over communications security (COMSEC) circuitryor over other approved circuitry?

Back 9

AUTOSEVOCOM

Front 10

Daily capacity of the AUTODIN system is about how many average-length messages?

Back 10

Five million

Front 11

What was established for the purpose of integrating the criticalintelligence communications (CRITICOMM) and the special intelligencecommunications (SPINTCOMM) networks into a single automatedcommunications network?

Back 11

DSSCS

Front 12

What network provides a voice link between the Chief of NavalOperations (CNO) and all subordinate commands ashore, afloat, andairborne?

Back 12

HICOM

Front 13

What meets our need for a connection between Navy tactical voicesystems of the operating forces and the various fixed telephone servicesashore?

Back 13

NORATS

Front 14

What is the principle use of the continuous wave?

Back 14

Radiotelegraphy

Front 15

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

Back 15

Antenna

Front 16

What is power the product of?

Back 16

Current and Voltage

Front 17

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 othersine wave quantity it helped make?

Back 17

Sub-harmonic

Front 18

What are special power amplifiers that multiply the input frequency?

Back 18

Frequency multipliers

Front 19

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

Back 19

Suppression

Front 20

What type of transmission is the most common communications modeused today?

Back 20

Single-sideband

Front 21

What is generally used whenever special voice communications circuitsare necessary between shore activities or between ships and shoreactivities because it is less susceptible to atmospheric interference thanamplitude modulation?

Back 21

SSB

Front 22

What is used extensively in naval communications to expand our trafficcapabilities?

Back 22

ISB

Front 23

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

Back 23

Reception, selection, detection, and reproduction

Front 24

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

Back 24

Reception

Front 25

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

Back 25

Selection

Front 26

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

Back 26

Detection

Front 27

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

Back 27

Reproduction

Front 28

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

Back 28

Sensitivity

Front 29

What is the limiting factor of sensitivity?

Back 29

Noise

Front 30

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

Back 30

Selectivity

Front 31

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

Back 31

Fidelity