ET VOL 3 CH 1,3 Flashcards Preview

2015 > ET VOL 3 CH 1,3 > Flashcards

Flashcards in ET VOL 3 CH 1,3 Deck (64)
Loading flashcards...
1

2

What type of equipment is used to coordinate the activities of fleet units by linking them with each other and shore stations?

Radio

3

Radio is the transmission and reception of electronic impulses or signals through space by means of what type of waves?

Electromagnetic

4

AN/UCC-1, AN/URA-17, and CV-2460 are examples of what type of shipboard equipment?

Terminal

5

___________ equipment is used primarily where coded transmissions are employed, to convert the modulated signal into the original intelligence.

Terminal

6

For efficient transmission, which of the following frequency bands require(s) high power and long antennas?

ELF, VLF, LF

7

Which of the following frequency bands has limited naval use?

MF

8

The super-high-frequency band is used extensively in what of communications?

Microwave

9

The emission class of an rf transmitter is based on what characteristic?

Modulation

10

An FM signal should remain constant in (a) what characteristic and change only in (b) what characteristic?

(A) amplitude. (B) frequency

11

What type of modulation is especially suited for use in time-division multiplexing?

Pulse

12

For modern communication needs, CW is not a preferred method. Why is this true?

CW is slow

13

In an FM transmitter, the audio signal shifts the carrier frequency in what network?

Phase-shift

14

In a ssb transmitter the carrier is removed to concentrate the power in the sideband(s) .

True

15

Which of the four receiver functions involves extraction of the modulation from the rf signal?

Detection

16

Which of the four receiver characteristics require compromise because of bandpass requirements ?

Selectivity and fidelity

17

The term “dBm” is based on what standard reference level?

1 milliwatt

18

What is formula for DBM?

DBM =actual power/.001 watt

19

Normal power out is 100 watts. During PMS, you discover that power out has dropped by 3dB. What is the new power out?

50 watt (3 db =50% of power) loss or gain)

20

How many radio set controls can be paralleled to one transmitter/ receiver group?

4

21

To transfer control of switched circuits to another transmitter or receiver switchboard, you should use what switch position?

(X) 1 Thru 6 are transmitters

22

Which of the following terms is used for a machine that operates as a single-phase transformer?

Synchro (light duty)

23

Of the two terms listed below, which one refers to reflection of radio signals back to earth by a satellite?

Passive

24

Which term refers to reception and retransmission?

Active

25

SATCOM links are only slightly affected by what phenomena associated with hf propagation difficulties?

Atmospheric

26

Trained crews can set up what type of satellite earth terminals within hours to establish communications in remote areas?

Mobile

27

factors, which, if any factors, limit the use of a satellite communications system?

1. Orbital parameters and technical characteristics 2. Transmitter power and receiver sensitivity

28

What purpose does CUDIXS/NAVMACS serve?

Provides a communications network for transmitting general-service message traffic between ships and shore installations

29

How many NCTAMS have primary responsibility for communications via satellite?

4 LANT Norfolk MED Naples WESTPAC finegayam Guam East PAC wahiam hi

30

Subsystems consist of two parts. What are they?

Satellite; rf terminal