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31 Cards in this Set
- Front
- Back
Frequencies above what are not normally refracted by the atmosphereand ground-wave range is minimal?
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30 megahertz
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The naval communications system is broken down into what groups?
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Strategic and tactical
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What type of communications are usually limited to a specific area ofoperations and are used to direct or report the movement of specificforces?
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Tactical
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What mode is a method of operation in which telecommunicationsbetween stations takes place simultaneously in both directions using twoseparate frequencies?
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Full-Duplex (fdx) |
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What is the type of operation in which one station transmitsinformation on one or more channels directed to more than one stationand/or unit? |
Broadcast (bc) |
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Message traffic is normally sent to the fleet by three methods:broadcast, intercept, and what else? |
Receipt |
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What combines into a single system all the elements that make up thenaval communications system and the Army and Air Force equivalent? |
DCS |
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What offers rapid, direct interconnection of DOD and certain othergovernment installations through worldwide telephone exchanges? |
DCS AUTOVON |
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What provides authorized users with a means for exchangingclassified information over communications security (COMSEC) circuitryor over other approved circuitry? |
AUTOSEVOCOM |
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Daily capacity of the AUTODIN system is about how many average-length messages? |
Five million |
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What was established for the purpose of integrating the criticalintelligence communications (CRITICOMM) and the special intelligencecommunications (SPINTCOMM) networks into a single automatedcommunications network? |
DSSCS |
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What network provides a voice link between the Chief of NavalOperations (CNO) and all subordinate commands ashore, afloat, andairborne? |
HICOM |
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What meets our need for a connection between Navy tactical voicesystems of the operating forces and the various fixed telephone servicesashore? |
NORATS |
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What is the principle use of the continuous wave? |
Radiotelegraphy |
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A cw transmitter requires four essential components. These are agenerator, amplifier, keyer, and what else? |
Antenna |
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What is power the product of? |
Current and Voltage |
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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? |
Sub-harmonic |
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What are special power amplifiers that multiply the input frequency? |
Frequency multipliers |
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What is the elimination of the undesired portions of the signal? |
Suppression |
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What type of transmission is the most common communications modeused today? |
Single-sideband |
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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? |
SSB |
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What is used extensively in naval communications to expand our trafficcapabilities? |
ISB |
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What four basic functions must a receiver perform in order to beuseful? |
Reception, selection, detection, and reproduction |
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What occurs when a transmitted electromagnetic wave passes throughthe receiver antenna and induces a voltage in the antenna? |
Reception |
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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? |
Selection |
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What is the action of separating the low (audio) frequency intelligencefrom the high (radio) frequency carrier? |
Detection |
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What is the action of converting the electrical signals to sound waves? |
Reproduction |
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What property is defined by the ability of a receiver to reproduceweak signals? |
Sensitivity |
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What is the limiting factor of sensitivity? |
Noise |
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What is the degree of distinction made by the receiver between thedesired signal and unwanted signals? |
Selectivity |
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What property of a receiver is its ability to accurately reproduce, in itsoutput, the signal that appears at its input? |
Fidelity
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