Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
260 Cards in this Set
- Front
- Back
|
The distance limit of the spacewave at VHF and UHF frequencies is the definition of what?
|
Line of Sight
|
|
|
The distance limit of the spacewave at VHF and UHF
frequencies is the definition of what? |
Transceiver
|
|
|
The combination of an Electric (E) field and Magnetic (H)
field is defined as a what? |
Electromagnetic Field
|
|
|
Electromagnetic waves traveling through a medium is the definition of what?
|
Propogation
|
|
|
A circuit that cuts off the output of a receiver when there is no input is what type of circuit?
|
Squelch
|
|
|
Total of reactance plus resistance. Measured in Ohm’s.
|
Impedance
|
|
|
Plane of propagation in which the E field radiates. The antenna determines which plane the electromagnetic energy is radiated. This defines what?
|
Polarization
|
|
|
The portion of a ground plane antenna that acts as ground.
|
Groundplane
|
|
|
Waves which are radiated with the E field component
perpendicular to the Earth’s surface. |
Vertically Polarized
|
|
|
A network of wire which is connected to a quarter wave antenna at the base and acts as a ground screen above ground.
|
Counterpoise
|
|
|
Mixing two frequencies across a nonlinear impedance.
|
Heterodyning
|
|
|
The VHF radio’s primary mission is what?
|
short range bridge to bridge communication with other vessels.
|
|
|
Coast Guard VHF Comms uses the _______ frequency range to provide Line of Sight (LOS) voice communication
|
146 to 175 MHz
|
|
|
The basic VHF system can be broke up into four broad catagories, they are what?
|
· Terminal equipment
· Transmitting/receiving equipment · Antennas · Power Supplies |
|
|
VHF Comms Systems Terminal equipment consists of all devices between and including the what?
|
operators station and the transmit/receive set. Control heads, microphones, and speakers are examples.
|
|
|
In VHF Comms systems the Transmit and receive equipment is usually combined into one unit called a ______ .
|
Transceiver
|
|
|
What is the purpose ot the transceiver?
|
It takes audio signals and turns them into an RF wave that is propagated by the antenna, as well as takes an RF signal and turns it back into audible voice
|
|
|
VHF Comms Antennas take the RF in its electrical form and change it into
__________ that can be ______ into space. |
electromagnetic energy, propagated
|
|
|
Most VHF Comms Systems use what as the primary power source.
|
12 VDC
|
|
|
The Coast Guard’s larger floating vessels use generators which provide _____ VAC.
|
115-120 VAC
|
|
|
Power supplies are used to convert the 115 vac to what?
|
Regulated 12 VDC
|
|
|
Terminal equipment provides the means for using the VHF Comms System. The terminal equipment allows what to happen?
|
· The operator to control different functions of the radio
· Voice and data to be converted into electrical energy · The operator to listen to the received information. |
|
|
The primary interface unit between the operator and a radio that does not have front panel controls is called the ____.
|
Control Head
|
|
|
Speakers allow for hands free what?
|
audio reception of the received intelligence
|
|
|
Critical factors in speaker selection and installation are what?
|
· Impedance
· Wattage · Polarity |
|
|
Microphones convert ___ energy into ___ energy.
|
acoustical, electrical
|
|
|
An antenna converts _____ at radio frequencies into _______ during transmission, this process is reversed for reception.
|
electrical energy, electromagnetic waves
|
|
|
The antenna must be able to radiate energy efficiently so _____ by the transmitter is not wasted.
|
power supplied
|
|
|
Considerations when procuring and installing VHF antennas are what?
|
· Gain
· Size and material · Durability · Placement · Groundplanes |
|
|
Gain of an antenna is not a what?
|
Increase in power output
|
|
|
Vertical antennas radiate _____ from the center point.
|
omnidirectional
|
|
|
In vertical antennas Gain is
achieved doing what? |
manipulating the electrical length of the antenna
conductor. |
|
|
What type of vertical antenna have a copper wire which is wound up and around a fiberglass rod, or the wire is fed thru the center of a fiberglass pole. They are typically ¼-wave antennas and usually just under five feet long.
|
Fiberglass Antennas
|
|
|
What type of vertical antennas are ½-wave antennas. Since the stainless steel rod is short, typically under 3 feet in length, these antennas need to be lengthened electrically. A wire coil is used to electrically lengthen the antenna. The coil is placed in-line at the antenna input. The term used to describe this type of antenna configuration is “End Fed”.
|
Stainless steel whip antennas
|
|
|
The longer size allows this antennas electromagnetic lobe to be highly focused. These antennas can be up to 10 ft in length and use specialized mounting hardware. What type of antenna is it?
|
5/8 wave or 10 db gain multisection fiberglass pole antennas
|
|
|
Ideally VHF antennas should be mounted where?
|
as high as possible to increase the LOS range
|
|
|
If the VHF antenna is placed on the mast of a vessel the electromagnetic lobe will travel in what direction compared to the surface of water?
|
parallel to the surface of the water.
|
|
|
Quarter wave antennas should be placed _______ to increase their range.
|
as high as possible
|
|
|
Power boats and large vessels benefit from the enhanced gain characteristics of what type of antenna?
|
the ½ and 5/8 wave antennas
|
|
|
A quarter wave antenna needs a proper ground plane to radiate the electromagnetic energy properly. Also called a counterpoise, its represents the other half of a ¼ wave antenna known as the _____ Antenna.
|
Image Antenna
|
|
|
Power supplies are used to provide the VHF Comm systems with what type of input power?
|
Regulated Input Power
|
|
|
What is the input voltage requirement for all Coast Guard VHF radio units?
|
12-14 Vdc, 13.8 Vdc being nominal.
|
|
|
The MCX-1000 requires how many amps when transmitting 30 watts, and how many amps when receiving a signal with the audio turned up.
|
8 amps transmitting and 1.8 amps receiving
|
|
|
Of the many power supplies available, the Coast Guard maintains what two types?
|
· Modar CGG-T-1670A Power Supply
· Modar CGG-T-1671A/TPN-1124A DC to DC Power Converter |
|
|
The Modar CGG-T-1670A Power Supply does what?
|
Converts 115-120Vac to 13.8 Vdc at 10 amps of available power.
|
|
|
The Modar CGG-T-1671A/TPN-1124A DC to DC Power Converter does what?
|
Converts 24/32Vdc to 13.6 Vdc at 8.5 amps of available power.
|
|
|
What are some reasons why Radio transceivers in the VHF frequency range are small compact units?
|
· VHF frequency range allows components to be smaller than lower frequency equipment.
· The communication range is LOS allowing for reduced power output, typically less than 50 watts. · The transmit and receive components are housed in one unit. This is called a transceiver. · Some components in the radio are used by both the transmit and receive functions. |
|
|
The basic FM transmitter combines the voice signal from a microphone and the sub carrier frequency from the master oscillator by a process called heterodyning, where does this take place?
|
in the phase shift network
|
|
|
LOS is the distance limit of what type of electromagnetic wave in the VHF Freq range?
|
Spacewave
|
|
|
The Electromagnetic Field is the combination of what two fields? _______and ______
|
electric field (E-field)
magnetic field (H-field) |
|
|
The frequency range of the VHF radio is _______ to ________.
|
146 MHz to 175 MHz
|
|
|
Vertically polarized antennas propagate energy _________ to the earth surface.
|
perpendicular
|
|
|
A mismatch of speaker impedance can degrade the _______ and _______ of the received signal.
|
clarity
amplitude |
|
|
What determines the physical length of an antenna?
|
frequency of the transmitted wave
|
|
|
The END FED antenna uses a ________ to electrically lengthen the antenna.
|
wire coil
|
|
|
Power supplies must provide adequate _______or_______ to ensure full power out of a radio.
|
current or amperage
|
|
|
A counterpoise represents one half of a ¼ wave antenna, this is called the ________.
|
image antenna
|
|
|
Heterodyning combines the ______and the ______ to produce a ________ in the phase shift network.
|
voice signal
master oscillator FM sub carrier |
|
|
The intermediate frequency in a FM receiver is actually the ______ frequency produced by mixing the RF carrier wave and the ______.
|
difference
local oscillator |
|
|
Is The MCX-1000 VHF Comms system is the Coast Guard’s only supported VHF radio system.
|
YES
|
|
|
EEPROM stands for what?
|
Electrically Erasable Programmable Read Only Memory.
|
|
|
DES stands for what?
|
Data Encryption Standard
|
|
|
The MCX-1000 has how many modes?
|
56 modes translates into available channels.
|
|
|
In the MCX-1000 what is a Zone?
|
Zone is collection of modes for geographical grouping
|
|
|
what is the frequency range of the MCX-1000?
|
136 to 162 MHz
|
|
|
What is the MCX-1000 primary power?
|
13.6 Vdc nominal, negative ground
|
|
|
what is the RF power out of the MCX-1000?
|
25 watts Hi power / 1 watt Lo power
|
|
|
What is the MCX-1000 receive and transmit current?
|
RCV = 1.8 amps
XMT = 8.0 amps |
|
|
What is the output Impedance of the MCX-1000?
|
50 Ohms
|
|
|
What is the frequency stability of the MCX-1000?
|
+/- 0.0005% which equates to 784 Hz at 156.8 MHz.
|
|
|
The FM noise of the MCX-1000 is rated at what level?
|
50 dB
|
|
|
What is the modulation level of the MCX-1000?
|
+/- 5 KHz
|
|
|
The guard receiver of the MCX-1000 is aligned to receive what channels?
|
16 (156.8 Mhz)
13 (156.65 Mhz) |
|
|
What are the three versions of the MCX-1000 used by the Coast Guard?
|
· CGG-MCX-1000 (V) 1, with Channel 16 Guard receiver
· CGG-MCX-1000 (V) 2, with Channel 13 Guard receiver · CGG-MCX-1000 (V) 3, No Guard receiver. |
|
|
Why must caution be used when ordering a replacment MCX-1000 transceiver thru the APA program?
|
Some radios are programmed for the “west coast”, and other are programmed for the “east coast”.
|
|
|
The MCX-1000 Marine VHF-FM is capable of _________ modes.
|
56
|
|
|
The output impedance of the MCX-1000 transmitter RF connection is
|
50 Ohms
|
|
|
Name two functions that can be altered by rotating a knob on the MCX-1000?
|
On / Off,
Main Speaker Volume, and Change Modes |
|
|
Receiver SINAD of the MXC-1000 is rated at
|
.35 uVolts
|
|
|
The microphone connection on the MCX-1000 control head can also be use to do what?
|
program the radio’s EEPROM
|
|
|
The radio’s chassis houses what major components?
|
RF Power Amplifier,
Receiver Front End, Frequency Synthesizer, Microcomputer / Analog Interface, and Main Board. |
|
|
Where on the transceiver is the connection for the control head cable located?
|
Front of transceiver
|
|
|
The accessory connection is used for the _______and ______.
|
external audio amplifier
muting circuits |
|
|
Name the two channels the Guard Receivers monitor?
|
Channel 13 at 156.65 MHz
Channel 16 at 156.80 MHz |
|
|
There are _______versions, and ______ system configurations of the MCX-1000.
|
Three
Two |
|
|
In a MCX-1000 dual head system configuration what two functions can be operated independently?
|
Audio levels of both the main and guard speakers, and display dimming of control head
|
|
|
Formed with a nickel hydroxide cathode, a cadmium anode, and a potassium hydroxide electrolyte. Each cell has operating voltage of 1.25 Vdc. This defines what?
|
NiCad Batteries
|
|
|
The rate of charging a battery is approximately 1/100 of its Ampere-Hour rating
|
Trickle Charge
|
|
|
MIL-STD-810(C-F), Can withstand immersion in 6 feet of salt water for up to 4 hours.
|
Immersion Proof
|
|
|
Of the many handhelds available for short range bridge-to-bridge communications, the Coast Guard supports three of these radios through the Return, Repair and Reissue Program (ELCINST 4408.1). What are they?
|
· CGC-MX-300R
· CGC-EXPO · CGC-Astro Digital Saber |
|
|
What is the most widley used Motorola VHF handheld radio used in the Coast Guard?
|
MX-300R
|
|
|
What Motorola VHF handheld is mostly used at shore units and is not as rugged as the MX-300R?
|
EXPO
|
|
|
What VHF handheld radio is replacing all current Coasy Guard supported handheld radios?
|
Astro Digital Saber
|
|
|
NiCad batteries, if not completely discharged during
normal operation before being recharged, will suffer from what? |
“memory effect”
|
|
|
What are the two types of battery chargers for NiCad batteries used on Coast Guard handheld radios?
|
· CGG-NLN-8988A Six Bay battery charger. 115Vac input
· CGG-NLN-8858A One Bay battery charger. 115Vac input. |
|
|
KVL stands for what?
|
Key Variable Loader (Key Loader)
|
|
|
Name three models of handheld radios in the VHF-FM range the Coast Guard supports.
|
CGG-MX-300R
CGG-EXPO CGG-SABER |
|
|
The output power of a hand held is approximately ______ watts.
|
5 watts
|
|
|
The Key Variable Loader is used to _______ into DES capable radios.
|
transfer keys
|
|
|
Memory effect in a NiCad battery can reduce the amount of ______ the battery can be utilized.
|
time
|
|
|
The Key Variable Loader display will read _______ when it is ready to load a radio.
|
“1 rEAdy”
|
|
|
What sound will be heard if the radio is keyed in coded operation, but not loaded with key variables?
|
An intermittent beep
|
|
|
Capable of only passing a selective range of frequencies
|
Narrowband
|
|
|
Capable of passing a broad range of frequencies.
|
Wideband
|
|
|
UHF Communication systems are used aboard Coast Guard ships for ____, ____, or ____ transmissions.
|
point-to-point, plain or secure voice
|
|
|
Because of the ______, UHF transmissions do not propagate outside the immediate area.
|
ultra high frequency
|
|
|
Coast Guard UHF Communication systems use the ____ frequency range to provide Line of Sight (LOS) voice communications.
|
225 to 400 MHz
|
|
|
UHF equipment is categorized into what three broad terms?
|
· Terminal equipment
· Transceiver · Antennas |
|
|
What is the primary transceiver used for UHF voice communications on board Coast Guard vessels?
|
AN/WSC-3
|
|
|
The AN/WSC-3 system is capable of communications via what two methods?
|
LOS or SATCOM
|
|
|
The RT-1107/WSC-3
Transceiver is available in how many versions? |
10 Versions
|
|
|
How many versions of the WSC-3 does the CG use? What are they?
|
4 Versions
Ver-6 (LOS) Ver-7 (LOS) Ver-8 (LOS) Ver-3A (SATCOM) |
|
|
Ultra High Frequency (UHF) antennas are ___ because of the short wavelength of UHF propagated radio waves.
|
Small
|
|
|
The Coast Guard uses two types of moderate-gain-directed antennas for fixed, point-to-point communications. What are they?
|
· AT-150/SRC.
· AS-390/SRC. |
|
|
C-11922/U is what piece of equipment?
|
RCU (Remote Control Unit) for the WSC-3
|
|
|
TA-970/U, TA-980/U and TA-990/U are used for what?
|
The telephone sets for the WSC-3. They provide voice communications in both the plain and cipher modes
|
|
|
The Type I: TA-970/U provides what type of comms for the WSC-3
|
single-channel voice communications capability from interior/below deck shipboard spaces
|
|
|
The Type II: TA-980/U provides voice communication capability for up to how many channels?
|
12 switch-selectable channels
|
|
|
The Type III: TA-990/U provides what type of comms for the WSC-3?
|
single-channel voice communication capability from exterior/above deck shipboard locations.
|
|
|
What is the frequency range used for the WSC-3 UHF Transceiver?
|
225.000 Mhz to 399.975 Mhz
|
|
|
How many possible channels does the WSC-3 have?
|
7000
|
|
|
What types of emissions does the WSC-3 provide?
|
AM plain and secure voice
FM plain and secure voice Link 11, FSK and PSK |
|
|
What is the output power of the WSC-3 transmitter in FM and AM modes?
|
FM-1 to 100 watts adjustable
AM-30 watts |
|
|
Which versions of the WSC-3 that the CG uses is capable of LOS voice communications?
|
Versions 6 and 7
|
|
|
What are the five major functions of the WSC-3 radio set?
|
transmit, receive, Built-In-Test Equipment (BITE), control, and power distribution
|
|
|
What is the voltage (power) needed to operate the WSC-3 radio set?
|
115/230-Vac, 60-Hz
|
|
|
THe built in test equipment (BITE) of the WSC03 radio set provides what?
|
limited continuous monitoring of the radio set functions without interference to the operational signals
|
|
|
What are the three things that will turn on the malfunction light of the WSC-3, what are they?
|
1. A power supply problem
2. A frequency problem 3. A bad BITE module. |
|
|
How many preset frequency channels are in the WSC-3?
|
20
|
|
|
The AN/WSC-3 Radio Set can be strapped for either ____ or ___ Vac.
|
115 or 230 VAC
|
|
|
LOS UHF Comms equipment is best suited for ______ range communication between ships and _____ during special operations.
|
short range
aircraft |
|
|
The military UHF frequency range is from _____ to
_____. |
225 to 400Mhz
|
|
|
Secure communication equipment _____/____ voice intelligence for transmission of sensitive information.
|
encrypt/decrypt
|
|
|
Terminal equipment includes all gear except for the main ______ and antenna systems.
|
transceiver
|
|
|
The _______ is the primary Radio Set used on Coast Guard vessels for communication in the UHF frequency range.
|
AN/WSC-3 (V)
|
|
|
The Radio Set _______ will identify which RT-1107/WSC-3 version is installed at your unit.
|
nameplate
|
|
|
Name the three types of A25 Interface Module used in the RT 1107/WSC-3.
|
Standard
SAS Switchable Audio |
|
|
What three problem areas will cause the AN/WC-3 transceiver malfunction lamp to light.
|
Power Supply
Frequency BITE module |
|
|
The __________ enables the technician to monitor the transceivers functions without interference to the operational signals
|
BITE
|
|
|
What is the recommended first step in troubleshooting the AN/WSC-3 system.
|
conduct a performance check
|
|
|
A character that represents one of the two digits (1 or 0) in the binary number system.
|
Bit
|
|
|
A data communication system can be described simply in terms of three components, what are they?
|
· Transmitting equipment
· Transmission medium · Receiving equipment. |
|
|
What is a simplex transmission mode?
|
Transmission occurs in only one direction.
Radio Beacon LORAN |
|
|
What is a half-duplex transmission mode?
|
Transmission occurs in both directions, but not at the same time.
SSB HFDL |
|
|
What is a Full-Duplex transmission mode?
|
Transmission occurs in both directions at the same time.
A standard telephone system. |
|
|
What is a byte?
|
A Byte is a string of bits that, when combined with each other, represents a character.
|
|
|
ASCII stands for what?
|
American Standard Code for Information Interchange
|
|
|
What is the most popular character encoding used today?
|
ASCII
|
|
|
What is a parity bit?
|
an optional data bit used for error detection.
|
|
|
Asynchronous transmission is used primarily for what?
|
slow speed (less than 19,200 bps).
|
|
|
Advantage of synchronous over asynchronous data transfer is what?
|
more efficient when transmitting large chunks of data
|
|
|
The RS-232 standard uses what kind of connector?
|
DB 25 “D” shape connector
· The DB 25 P (P for plug) connector is used with DTE · The DB 25 S (S for socket) connector is used with DCE |
|
|
what is the maximum length of cable and the maximum data rate for a cable using a DB-25 connector?
|
50 Feet
20k bps |
|
|
A ______ is a piece of equipment that combines data from several inputs into one continuous serial data stream for transmission over a single communication channel.
|
multiplexer
|
|
|
There are three basic types of multiplexing techniques used in data communication. What are they?
|
· Frequency division multiplexing (FDM)
· Time division multiplexing (TDM) · Statistical multiplexing (STDM) |
|
|
What multiplexing technique takes the frequency spectrum of one leased land line, and subdivides it into a series of smaller frequency bands.
|
Frequency Division Multiplexing (FDM)
|
|
|
Which multiplexing technique is a process in which two or more channels of information are transmitting over the same transmission medium by allocating a different time interval (time slot) for the transmission of each channel.
|
Time Division Multiplexing (TDM)
|
|
|
Which multiplexing technique is the same as TDM, but instead of having each time slot fixed, they are variable in length.
|
Statistical Multiplexing
|
|
|
Frequency division multiplexing (FDM), Time division multiplexing (TDM), Statistical multiplexing (STDM) are the basic multiplexing techniques. What is another technique that works with UHF Satellites?
|
Time Division Multiple Access
(TDMA) |
|
|
The word modem is an acronym for what?
|
modulator/demodulator
|
|
|
What is defined as the impression of intelligence upon a transmission medium, such as radio waves.
|
Modulation
|
|
|
What are the two most common types of modulation schemes used in communication equipment?
|
· FSK (Frequency Shift Keying)
· PSK (Phase Shift Keying) |
|
|
Asynchronous modems use _______ modulation and are restricted to low speed applications.
|
frequency shift keying (FSK),
|
|
|
What type of modulation is used for medium speed (2400 to 4800 bps) synchronous modems.
|
Phase shift keying (PSK)
|
|
|
What are two types of PSK techniques that are in use?
|
· BPSK (Bi-Phase Shift Keying)
· QPSK (Quadri-Phase Shift Keying) |
|
|
________ provides the functions required to establish, maintain, and terminate a connection, and provides the signal conversion required for communications between data terminal equipment and the telephone line or data circuit.
|
Data Communication Equipment (DCE)
|
|
|
________ develops the data source and/or accepts data signals from a transmission device, and provides for the communication control function protocol. It includes any piece of equipment at which a communication path begins or ends.
|
Data Terminal Equipment (DTE)
|
|
|
Which type of character encoding that requires 7 or 8 bits is? (Baudot or ASCII)
|
ASCII
|
|
|
Which type of character encoding requires 5 bits is? (Baudot or ASCII)
|
Baudot
|
|
|
A _______ bit is an additional data bit added at the end of an ASCII character and is used for error detection.
|
party
|
|
|
( True or False) The party bit will detect all errors that occur during transmission of a character?
|
False
|
|
|
What type of serial transmission requires the use of Start and Stop bits?
|
Asynchronous
|
|
|
Name three types of Multiplexing Techniques:
|
Frequency Division Multiplexing (FDM)
Time Division Multiplexing (TDM) Statistical Multiplexing (STDM) |
|
|
What type of serial transmission is more efficient when transmitting large chunks of data?
|
Synchronous
|
|
|
Name two types of modulation techniques:
|
Frequency Shift Keying (FSK)
Phase Shift Keying (PSK) |
|
|
When troubleshooting a data comms system you should know what three important things?
|
· the signal flow of the system
· your equipment and its features, and · information about the signal |
|
|
One of the basic techniques for isolation of faults in data communications is what kind of test?
|
Loopback Test
|
|
|
The GRM-10208-1 patch panel plug allows the technician what when troubleshooting?
|
a visual aid in determining if a signal is present at the patch pannel
|
|
|
When the GMR-10208-1 patch pannel plug light alternates between red and green it is an indication of what?
|
An active TTY signal is present
|
|
|
When the GMR-10208-1 patch pannel plug light is red it is an indication of what?
|
Space signal is present
|
|
|
When the GMR-10208-1 patch pannel plug light is green it is an indication of what?
|
Mark signal is present
|
|
|
The data line monitor allows the technician to monitor the condition of what three line types?
|
· Data Lines
· Control Lines · Ground Lines |
|
|
The breakout box allows the technician to monitor and measure the condition of what 5 line types?
|
· Data Lines
· Control Lines · Ground Lines · Time Lines · Secondary Lines |
|
|
If you have a redundant system, _______ or _______ can help eliminate certain communication equipment.
|
patching or switching
|
|
|
To determine if your communication equipment has a built in self test, you should
|
Refer to the equipment’s technical manual
|
|
|
A _______ normally has the ability of performing a loopback test.
|
modem
|
|
|
The ________ may eliminate the need for a DC voltmeter to test the GRM patch panel.
|
GRM-10208-1 patch panel plug
|
|
|
A Data Line Monitor allows the technician to monitor the condition of:
__________Lines __________Lines __________Lines |
Data Lines
Control Lines Ground Lines |
|
|
The ______ is a sophisticated type of test equipment that allows the technician to view the data that is being transmitted.
|
protocol analyzer
|
|
|
A breakout box can be used in conjunction with what two pieces of test equipment?
|
Voltmeter
O’scope |
|
|
What is defined as The portions of the TDMA frame used for the transmission of management, control, and status information between the channel controllers and terminal users.
|
Orderwire
|
|
|
What are 4 advantages of satellite comms?
|
· reliable
· survivable · secure · cost effective. |
|
|
Most satellites will use different frequencies for the Up and Down Links, this is to do what?.
|
prevent interference between the two Links
|
|
|
What are two type of communications satellites that you will encounter?
|
· Active - acts as a repeater, it amplifies signals received and then retransmits them back to earth.
· Passive - reflects received radio signals back to earth. |
|
|
What two thing are necessary to overcome up-link limitations and to ensure that the signals received by the satellite are strong enough to be detected.
|
High-powered transmitters, and highly directional high-gain antennas
|
|
|
There is a delay time in satellite comms of approx. how long from the time data is transmitted to the time it is received. This delay varies with the latitude and longitude of the earth stations.
|
0.25 Seconds
|
|
|
There are three parameters used to describe the orbit of a satellite. What are they?
|
Perigee
Apogee Angle of Inclination |
|
|
The Angle of Inclination determines what?
|
The area covered by the path of the satellite, the greater the angle of inclination, the greater the coverage area.
|
|
|
The satellites that the Coast Guard uses are in a what type of orbit?
|
geosynchronous orbit
|
|
|
The geosynchronous satellite will appear to be what?
|
stationary over one point of the earth’s surface
|
|
|
Three geosynchronous satellites can provide what?
|
coverage over most of the earth
|
|
|
The Coast Guard uses what satellite system?
|
The Navy’s UHF Satellite Communications (SATCOM) system
|
|
|
The UHF SATCOM system provides world-wide coverage between what latitudes?
|
latitudes of 70 degrees north and 70 degrees south
|
|
|
NCTAMS stands for what?
|
Naval Computer and Telecommunications Area Master Stations
|
|
|
Who has primary responsibility for Naval UHF communication via satellites?
|
NCTAMS
|
|
|
What are the four NCTAMS sites?
|
· NCTAMS Lant- Norfolk, Va
· NCTAMS Med- Bagnoli, Italy · NCTAMS Westpac - Finegayan, Guam · NCTAMS Eastpac- Wahiawa, Hawaii |
|
|
INMARSAT stands for what?
|
Internation Maritime Satellite Organization
|
|
|
The purpose of INMARSAT is to provide what?
|
mobile satellite communications to the international maritime and offshore industries
|
|
|
The Coast Guard uses two different types of INMARSAT, what are they?
|
· Standard A
· Standard C |
|
|
The Coast Guard uses what two multiple access systems?
|
· Frequency Division Multiple Access (FDMA)
· Time Division Multiple Access (TDMA) |
|
|
The DAMA multiplexed data stream is divided into frames; each frame is ____ in length.
|
1.386 seconds
|
|
|
The Uplink and Downlink frequencies are ______ frequencies.
|
different
|
|
|
A _____ obit has the same rotation as the earth and is positioned over the equator.
|
geosynchronous
|
|
|
A typical satellite communication system consist of what three elements?
|
Ground Base Station
Satellite Earth Terminals |
|
|
The coverage area of the Navy’s UHF Satellite Communications (SATCOM) system is between the latitudes of __ degrees north and __ degrees south.
|
70° North and 70° South
|
|
|
What type of satellite acts as a repeater and amplifies signals received, and then retransmits them back to earth?
|
An active satellite
|
|
|
Name two Multiple Access systems used in satellite communications:
|
Frequency Division Multiple Access (FDMA)
Time Division Multiple Access (TDMA) |
|
|
(True or False) IMARSAT is a commercial satellite system used by the Coast Guard.
|
True
|
|
|
VME stands for what?
|
Versa Module Eurocard
|
|
|
The UHF SATCOM System contains what subsystems?
|
· Fleet Satellite Broadcast (FSB)
· Demand Assigned Multiple Access (DAMA) · Naval Modular Automated Communications Subsystem (NAVMACS) · Satellite High Command/Narrow Band Secure Voice (SATHICOM/NBSV) · Officer in Tactical Command Information Exchange Subsystem (OTICIXS) · Satellite Radio Teletype (SATRAT) |
|
|
FSB (Fleet Satellite Brodcast) functions as a what?
|
receive-only message terminal
|
|
|
What type of antenna is used in the FSB subsystem?
|
AS-2815/SSR-1
|
|
|
FSb antennas (AS-2815/SSR-1) are designed to receive transmissions at what frequency range?
|
240 - 315 MHz
|
|
|
An expansion of existing teletypewriter communication network.
|
SATRAT
|
|
|
A two way satellite link to support Over-the-Horizon (OTH) communications for battle group command and control, and tactical targeting.
|
OTICIXS
|
|
|
The primary means for ships to receive general service message traffic.
|
FSB
|
|
|
Secure voice communications via satellite relay.
|
SATHICOM
|
|
|
A method of transmitting general service message traffic between ships and shore terminals.
|
CUDIXS / NAVMACS
|
|
|
Multiplexes several baseband systems onto one 25-kHz satellite channel.
|
DAMA
|
|
|
Name the three subsystems that the DAMA system multiplexes into one 25-kHz satellite channel:
|
CUDIXS/NAVMACS
SATHICOM SATRAT |
|
|
Name the two different operational modes of the DAMA’s TD-1271 multiplexer:
|
Automatic Control (AC)
Distributed Control (DC) |
|
|
The WSC-3 transceiver used in a UHF satellite communication system is the same transceiver used in a UHF Line of Sight system. (True or False)
|
False
|
|
|
The HD-2R Versatron Interface used in the NAVMACS, is used to convert _____ to _____ ,and _____ to _____.
|
RS-232 to Mil-STD-188C
and Mil-STD-188C to RS-232 |
|
|
What is a lightweight UHF SATCOM system installed on 210 WMECs and selected stations to enhance communication interoperability between units of the Department of Defense (DOD) and various law enforcement agencies.
|
LST-5C
|
|
|
The LST-5 Radio Set is an AM/FM, UHF
transceiver used for what three purposes? |
· Half-duplex
· Line of sight · Satellite Communications |
|
|
The "Batwing" antenna is what type of antenna?
|
omni directional and does not need to be pointed at a satellite
|
|
|
The LST-5C uses an antenna called the ______ ?
|
"Batwing"
|
|
|
The AM-7175/URC is a solid state, highly reliable power amplifier unit providing up to how much power?
|
200-watts of power output
|
|
|
The LSTA -101 shock tray assembly is used to mount and supply various voltages to what LST-5C equipment?
|
· AM-7175/URC Power Amplifier
· LST-5C Transceiver · AN/CSZ-1A Sunbust Processor |
|
|
What is the major reason for the upgrade from the LST-5C to the LST-5D?
|
the LST-5D is DAMA capable
|
|
|
The antenna used for the LST-5D is the _____?
|
AV-2098
|
|
|
is the LST-5D antenna directional or omni-directional?
|
a directional antenna and always needs to be pointing toward the satellite
|
|
|
The LST-5 ___UHF SATCOM system has embedded COMSEC and DAMA capability.
|
D
|
|
|
The LST-5C AM-7175/URC power amplifier can replace the AM-7175D power amplifier used in the LST-D. (True or False)
|
False
|
|
|
The INMARSAT A provides the capabilities for what?
|
Telephone
Facsimile Data Communication Telex |
|
|
The LST-5C has a omni-directional antenna. (True or False)
|
True
|
|
|
Name the two INMARSAT-A systems found in the Coast Guard:
|
MCS-9120
MX 2400 |
|
|
The INMARSAT-C system provides voice communications. (True or False)
|
False
|
|
|
You read in the technical manual that a transceiver operates in the Half- Duplex mode. Half Duplex mode means that the transceiver.
A. is only able to transmit B. transmits and receives at the same time C. is only able to receive D. transmits and receives, but not at the same time |
D. transmits and receives, but not at the same time
|
|
|
You are transmitting an ASCII character using even parity. Which of the following bit patterns would represent this?
A. 1 0 0 0 1 0 1 1 B. 0 0 0 1 0 0 0 0 C. 1 1 1 0 0 0 1 1 D. 0 1 1 1 0 0 0 0 |
A. 1 0 0 0 1 0 1 1
|
|
|
You are troubleshooting a modem in your communications system. The signal at the output of the modem is a _____.
A. digital signal B. audio signal C. multiplex signal. D. statistical signal |
B. audio signal
|
|
|
The four AS-2815/SSR-1 antennas used in the Fleet Broadcast Subsystem are omin directional. Omin directional antennas require _____.
A. the use of an antenna controller to point the antennas towards the satellite B. no special requirement C. the antennas to be located with in the footprint of the satellite D. an Amplifier Filter Bandpass |
C. the antennas to be located with in the footprint of the satellite
|
|
|
You are communication using INMARSAT-C and notice a 5 minute delay between transmitting a message and receiving an answer. What should you do?
A. Nothing this is normal. B. Perform a functional check on the transceiver. C. Adjust the output power of the transceiver. D. Adjust the position of the antenna. |
A. Nothing this is normal.
|
|
|
Your guard receiver is setup to monitor what two channels.
A. Channel 13 and Channel 10 B. Channel 13 and Channel 16 C. Channel 10 and Channel 18 D. Channel 16 and Channel 18 |
B. Channel 13 and Channel 16
|
|
|
What would you suspect if one of your handheld radios only operates for an hour after being fully charged?
A. Nothing this normal operation B. The Wrong type of batteries have been installed. C. The batteries suffer from memory effect. D. The charging unit needs replacing. |
C. The batteries suffer from memory effect.
|
|
|
For short-range communications between bridge-to-bridge , and bridge-to-Boarding parties, the _____ Communication system is used.
A. UHF B. VHF C. SATCOM D. VLF |
B. VHF
|
|
|
The AN/WSC-3 UHF transceiver is used in the Coast Guard for both ____.
A. Line-of-Sight and Satellite Communications B. Line-of-Sight and Long Range Communications C. Long Range and Satellite Communications D. Ground and Long Range Communications |
A. Line-of-Sight and Satellite Communications
|
|
|
Which of the following functions of the MCX-1000 can NOT be performed via the control head?
A. Turn on/off the radio. B. Change the transceiver channel. C. Select transmit/receive antenna. D. Select clear or coded transmission. |
C. Select transmit/receive antenna.
|
|
|
What is the correct test equipment to use to determine if a signal is present at a Red Patch Panel?
A. Breakout Box B. Data Line Monitor C. Protocol Analyzer D. GRM-10208-1 Patch Panel Test Plug |
D. GRM-10208-1 Patch Panel Test Plug
|
|
|
What is the correct test equipment to use to view text being transmitted across data lines?
A. Breakout Box B. Data Line Monitor C. Protocol Analyzer D. GRM-10208-1 Patch Panel Test Plug |
C. Protocol Analyzer
|
