At Exam

Front 1

Purpose of Radar timer

Back 1

to synchronize the sweep voltage or current for the indicator with the transmitter pulse.

Front 2

Function of the synchronizer is

Back 2

to produce the trigger pulse that starts the transmitter.

Front 3

the function of the majority of circuits in radars is

Back 3

timing or control

Front 4

radar systems are classified by wither

Back 4

self-synchronized of externally synchronized

Front 5

timing trigger of externally synchronized systems is obtained from what

Back 5

master oscillator

Front 6

in self-synchronized system timing of trigger pulse is obtained from what

Back 6

the transmitter

Front 7

the CRT stands for what

Back 7

cathode- ray tube

Front 8

the basic timing circuit should meet what 3 basic requirements

Back 8

Must be free-running (astable), must be stable in frequency, frequency must be variable in steps

Front 9

purpose of radar transmitter is to develop

Back 9

high power, high frequency pulses of RF energy to be radiated by antenna system

Front 10

transmitting devices used in fire control

Back 10

magnetrons, klystrons, gallium arsenide oscillators

Front 11

what controls the radar pulsewidth by use of rectangular dc pulse.

Back 11

radar modulator

Front 12

timing circuit must be triggered on the

Back 12

leading edge

Front 13

what synchronizes the CRT sweep circuits and target range

Back 13

the trigger pulse

Front 14

two types of modulators

Back 14

line-pulsing and drive-hard-tube

Front 15

line-pulsed modulator is easier to maintain because

Back 15

less complex, more compact, and light

Front 16

components of the radar modulator

Back 16

power supply, storage element, charging impedance, modulator switch

Front 17

a circuit element of network for storing energy

Back 17

storage element

Front 18

to control the charge time of storage element and to prevent shot-circuiting of power supply

Back 18

charging impedance

Front 19

to discharge the energy stored by the storage element through the transmitter oscillator

Back 19

modulator switch

Front 20

these are used only in modulators that have dc power supply and electron-tube modulator

Back 20

Capacitor

Front 21

the electron tube modulator switch controls

Back 21

the charge and discharge of the capacitor storage

Front 22

a thyratron conducts when

Back 22

a positive trigger pulse is applied to its grid

Front 23

the radar receiver must have

Back 23

high gain and low noise

Front 24

a waveguide arrangement with four branches constructed so that energy of one of the four branches is coupled to two of the three branches

Back 24

hybrid T or Magic T

Front 25

most modern radars use

Back 25

solid-state, variable frequency, voltage-controlled, varactor oscillators

Front 26

a semiconductor device employed as a variable reactance circuit element

Back 26

varacotr diode

Front 27

variable reactance is provided by

Back 27

the P-N junction capacitance

Front 28

operates between positive bias and reverse breakdown voltage

Back 28

varactor diode

Front 29

purpose of AFC circuits

Back 29

to tune the receiver local oscillator to the correct operating frequency

Front 30

three basic modes of operation for AFC

Back 30

search, acquisition, loop control modes

Front 31

simplest type of AGC adjusts

Back 31

the IF amplifier bias according to the avg level of receiver signal

Front 32

gain is controlled by

Back 32

the largest received signals

Front 33

used to amplify the output signal from the video detector to a high level enough to be used by the radar presentation system

Back 33

video amplifier

Front 34

the simplified block diagram, presented to establish a basic understanding of scopes

Back 34

A-scope

Front 35

B-scan

Back 35

Range, azimuth, intellegence received

Front 36

used to present data on the bearing elevation of targets

Back 36

c scope

Front 37

Plan-position indicators PPI-scopes

Back 37

an exact replica of the region scanned

Front 38

negative trigger pulses from timer are applied to

Back 38

the sweep multivibrator

Front 39

a pulse-type transmitter triggered by the code synchronizer

Back 39

interrogator

Front 40

how many modes of IFF

Back 40

5

Front 41

Mode 1 and Mode 2

Back 41

used for military only

Front 42

Modes 3/A

Back 42

military and civilian

Front 43

Mode 4

Back 43

military enrypted mode or classified

Front 44

MASTER control switch has how many positions

Back 44

5