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14088
Communications systems
Question | Answer |
---|---|
What term is normally used for microwave transmitter input signal? | Baseband Signal |
In a microwave transmitter, the linearize couples a portion of the output power back to the klystron. This allows for modulation densities as high as 1200 channels and compensates for what klystron deficiency? | Nonlinearity |
During UHF secure voice transmission, the operator uses a secure voice remote phone unit. What is the common term for this unit? | RPU |
In a typical microwave receiver, what is the standard intermediate frequency? | 70 MHZ |
Which of the following methods are usually used for microwave communications? | Los and troposcatter |
By which of the following methods can you increase the maximum number of intelligible signals transmitted on a single path? | Multiplexing |
Which of the following communications methods involves subdividing a channel into smaller segments of equal size and placing a signal in each subchannel? | FDM |
Which of the following requirements does SAS satisfy? | All of the above |
How many crypto and plain subsystems are used within SAS? | Five |
One mode of teletypewriter operation is the synchronous mode. What other mode is used for basic teletypewriter operation? | Asynchronous |
What is the name of the fiveunit code that includes mark and space signals and is used in teletypewriter operation? | Baudot |
Which of the following problems is reduced by not using start and stop signals in the synchronous teletypewriter mode? | Distorted signal |
Which of the following terms accually pertains only to modulation rate? | Baud |
In neutral tty operation, current flow and no current flow represent the mark and space conditions. In polar tty operation what is the condition of the line current? | It is always present |
What device is used to change tty dc pulses into mark and space signals to modulate the transmitter carrier wave? | Keyer |
After the tty signal is received, what device(s) must be used to change the signal back to dc pulses? | Both 1 and 2 |
The Navy’s two basic RATT systems are AFTS and RFCS. What is the RFCS system commonly called? | FSK |
What device provides looping current for the tty? | A solid state pwoer supply |
What is/are used to interconnect all the tty equipment in any configuration needed? | TTY panel |
Which of the following methods is/are used to reduce fading and interference in long-range communications? | Both 1 and 2 |
What type of frequency diversity is used for multichannel broadcasts? | Tone |
During unpatching, pulling which plug from its tty panel jack first will produce a dangerous dc voltage on the exposed plug? | Set |
How many rotary switch positions will you find on a remote transmitter control unit? | Three |
In AFTS, to what does the term “half-duplex” refer? | All of the above |
Which of the following methods should you use to transmit printed text? | Facsimile |
In which of the following publications can you find information on TEMPEST requirements? | MIL-STD-1680 |
What is the designator of any conductor intended to carry classified plain language terminating in RED equipment or the RED side of crypto equipment? | Primary Red |
Of the following radios, which is popularly known as the “Gibson girl”? | AN/CRT-3A |
Which of the following radios provides homing and two-way voice communications between liferafts and searching ships? | AN/PRC-96 |
Which of the following radios is particularly useful during tactical black-out operations? | AN/PRC-104 |
Which of the following radios has frequency hopping capability? | AN/PRC-117 |
The use of frequency hopping has certain advantages. One advantage is that the signal is difficult to detect. How is this accomplished? | No single carrier is used |
One important feature of the AN/PSC-3 uhf radio is that it can interface directly with vhf radios. What is the purpose of this interface? | To provide a satellite link for vhf radios |
DMDG messages are sent at 300 or 1200 baud in the satellite mode and 266.6 baud when connected to AN/PRC-70/74.Which of the following is the device used to type and read these messages? | KY-879/P |
What system was specifically designed to provide solutions to equipment planning by automatically determining the best system that each participant in a communications link should use? | CLIPS |
Of the two terms listed below, which one refers to reflection of radio signals back to earth by a satellite? | Passive |
Which term refers to reception and retransmission? | Active |
Which of the following terms refers to transmissions received from a satellite? | Downlink |
SATCOM links are only slightly affected by what phenomena associated with hf propagation difficulties? | Atmospheric |
Trained crews can set up what type of satellite earth terminals within hours to establish communications in remote areas? | Mobile |
Of the following factors, which, if any, limit the use of a satellite communications system? | Both 1 and 2 |
What purpose does CUDIXS/NAVMACS serve? | Provides a communications network for transmitting general-service message traffic between ships and shore installations |
How many NCTAMS have primary responsibility for communications via satellite? | 4 |
Subsystems consist of two parts. What are they? | Baseband equipment; rf terminal |
In modes 1 through 6, what are the uplink and downlink frequency bands used in Fleet Satellite Broadcast? | Shf; uhf |
What system do subscribers use to receive Fleet Satellite Broadcast? | AN/SSR-1 |
What is the minimum number of broadcast channels that NAVMACS guards automatically? | 4 |
What is the bandwidth (in kHz) of the satellite channels allocated to CUDIXS/NAVMACS? | 25 |
What term is associated with a submarine commander’s ability to receive messages via satellite at scheduled intervals? | Group broadcasts |
Secure voice uses digitized voice with a 3-kHz voice channel. What type of voice modulation does this describe? | Narrowband |
When using Secure Voice, a ship must contact what authority before initiating communications with a shore command? | Voice controller |
Which of the following is a subsystem specifically designed for special intelligence communications? | TACINTEL |
TADIXS-equipped surface ships and submarines operate in what mode(s)? | Receive only |
What subsystem is used in conjunction with TADIXS to transmit OTH-T data from the fleet to other ships and shore commands? | OTCIXS |
Because the reception of TADIXS information by a ship does not require an acknowledgement, the ship can l operate in what type of environment and still receive message traffic? | Emission control |
What system was developed to multiplex several users on one 25-kHz satellite channel? | DAMA |
What term is used to describe how the Demand Assigned Multiple Access data stream is formatted? | Frame |
In the DAMA multiplexed data stream, which slot is used to test for communications error? | Link |
What are all DAMA multiplexer transmit times referenced to? | The satellite |
Which of the following equipments is used as the DAMA multiplexer? | TD-1271B/U |
Who performs day-to-day control and operation of naval satellite communications assets? | Naval Computer and Telecommunications Command |
Of the 23 uhf communications channels each FLTSATCOM satellite has, how many one dedicated to Navy use? | 10 |
How many FLTSATCOM satellites have ehf packages installed? | 2 |
LEASAT satellites have fewer 25-kHz channels than FLTSATs. What ground-based system do they use to maintain communications efficiency? | DAMA |
What is the replacement satellite for GAPFILLER, FLTSATCOM, and LEASAT? | UHF F/O |
The AN/FSC-79 satellite communications terminal transmits on what band? | Shf |
Which of the following is another term used to describe the shf communications band? | X-band |
The AN/WSC-5(V) uhf transceiver is capable of using differentially encoded phaseshift- keying and what other type of modulation? | FM |
Which of the following radios is the primary shipboard los and satellite transceiver? | AN/WSC-3 |
The AN/WSC-3 transceiver has two rf output levels. One of these is 30 watts. What is the other rf output level? | 100 Watts |
What shipboard system is used to receive Fleet Satellite Broadcast? | AN/SSR-1 |
Which of the following is a spread spectrum type modem and is used with the AN/FSC-79 satellite communications terminal? | OM-51A/FR |
Of the two processors listed below, which one is used in the TADIXS subsystem? | AN/UYK-44(V) |
The AN/USQ-69(V) data terminal set is currently used with what two subsystems? | TACINTEL/NAVMACS |
Audio digital converter CV-3333/U is used primarily as an analog-to-digital converter for what type of communications? | Secure voice |
Where are the system interface connectors installed on the Electrical Equipment Rack CY-7597/WSC-3? | On the top panel |
DAMA-equipped shore installations use the OK- 481(V)2/FSC Control Monitor Group to interface TD-1271B/Us, AN/WSC-5(V)s, and baseband equipment. It can accommodate up to how many TD-1271B/Us? | 14 |