ISCET RADAR FLASHCARDS EXAM QUESTIONS AND ANSWERS
To install and maintain a RADAR, you must have: - CORRECT ANSWER✅✅GROL w/ Radar or GMDSSIM
w/ Radar
Who may replace fuses and receiving type tubes and circuits in a Radar? - CORRECT ANSWER✅✅Holder
of GROL w/ Radar
Under what circumstances can an unlicensed person operate a radar set? - CORRECT ANSWER✅✅Only
if the Tx is a non-tunable type and when the master of the ship designated him to operate it
What Radar maintenance work may be done by unlicensed workers? - CORRECT ANSWER✅✅None
Who is permitted to operate a ship Radar? - CORRECT ANSWER✅✅Master of the ship, or anyone
designated by the master.
What is box 46 of EL8-A? - CORRECT ANSWER✅✅TR Box
What is box 47 of EL8-A? - CORRECT ANSWER✅✅RF Attenuator
What is box 48 of EL8-A? - CORRECT ANSWER✅✅Klystron
What is box 49 of EL8-A? - CORRECT ANSWER✅✅Crystal Detector
What is box 50 of EL8-A? - CORRECT ANSWER✅✅Discriminator
The minimum range of a Radar is primarily determined by: - CORRECT ANSWER✅✅The pulse width and
TR (TRL) cell recovery time
An RF mixer has what purpose in a Radar system? - CORRECT ANSWER✅✅It converts low-level signal to
a different frequency
,The switching devices most commonly used in pulse networks, and pulse transformers are/is: - CORRECT
ANSWER✅✅SCR's and Thyratrons
Good bearing resolution largely depends upon: - CORRECT ANSWER✅✅A narrow antenna beam in the
horizontal plane
Bearing Resolution is: - CORRECT ANSWER✅✅The ability to distinguish two adjacent targets of equal
distance.
An artificial line is used for: - CORRECT ANSWER✅✅Determining the shape and durations of the pulses
What device is located between the magnetron and the mixer and prevents received signals from
entering the magnetron? - CORRECT ANSWER✅✅The ATR box
The ATR Box: - CORRECT ANSWER✅✅Prevents the received signal from entering the transmitter
When a pulse radar is radiating, which elements in the TR box are energized? - CORRECT
ANSWER✅✅The TR and ATR tubes
In the AFC system, the discriminator compares the frequencies of the: - CORRECT
ANSWER✅✅Magnetron and Klystron
The purpose of the discriminator circuit in a Radar is to: - CORRECT ANSWER✅✅Generate a corrective
voltage for controlling the frequency of the klystron local oscillator
Where is the RF Attenuator used in a Radar? - CORRECT ANSWER✅✅Between the Magnetron and AFC
section of the receiver
What frequency is the discriminator tuned to? - CORRECT ANSWER✅✅30 MHz IF
, The usual intermediate frequency of a shipboard Radar unit is: - CORRECT ANSWER✅✅30 or 60 MHz
The error voltage from the discriminator us applied to: - CORRECT ANSWER✅✅The repeller (reflector)
of the klystron
How may the frequency of the klystron be varied? - CORRECT ANSWER✅✅Small changes can be made
by adjusting the repeller voltage and large changes can be made by adjusting the size of the resonant
cavity
Fine adjustment of the reflex klystron are accomplished by: - CORRECT ANSWER✅✅Varing the repeller
voltage
The pulse repetition rate (PRR) refers to: - CORRECT ANSWER✅✅The pulse rate of the magnetron
The timer circuit: - CORRECT ANSWER✅✅Determines the PRR, determines range markers, and provides
blanking and unblanking signals for the CRT
On what frequency is radar expected to cause interference? - CORRECT ANSWER✅✅On most any
communication frequency
If the magnetron is allowed to operate without the magnetic field in place: - CORRECT ANSWER✅✅It
will quickly destroy itself from excessive current flow
What radar circuit determines the pulse repetition rate (PRR)? - CORRECT ANSWER✅✅The timer
(syncronizer circuit)
Range markers are determined by: - CORRECT ANSWER✅✅The timer
Unblanking pulses are produced by the timer circuit. Where are they sent? - CORRECT ANSWER✅✅To
the CRT
To install and maintain a RADAR, you must have: - CORRECT ANSWER✅✅GROL w/ Radar or GMDSSIM
w/ Radar
Who may replace fuses and receiving type tubes and circuits in a Radar? - CORRECT ANSWER✅✅Holder
of GROL w/ Radar
Under what circumstances can an unlicensed person operate a radar set? - CORRECT ANSWER✅✅Only
if the Tx is a non-tunable type and when the master of the ship designated him to operate it
What Radar maintenance work may be done by unlicensed workers? - CORRECT ANSWER✅✅None
Who is permitted to operate a ship Radar? - CORRECT ANSWER✅✅Master of the ship, or anyone
designated by the master.
What is box 46 of EL8-A? - CORRECT ANSWER✅✅TR Box
What is box 47 of EL8-A? - CORRECT ANSWER✅✅RF Attenuator
What is box 48 of EL8-A? - CORRECT ANSWER✅✅Klystron
What is box 49 of EL8-A? - CORRECT ANSWER✅✅Crystal Detector
What is box 50 of EL8-A? - CORRECT ANSWER✅✅Discriminator
The minimum range of a Radar is primarily determined by: - CORRECT ANSWER✅✅The pulse width and
TR (TRL) cell recovery time
An RF mixer has what purpose in a Radar system? - CORRECT ANSWER✅✅It converts low-level signal to
a different frequency
,The switching devices most commonly used in pulse networks, and pulse transformers are/is: - CORRECT
ANSWER✅✅SCR's and Thyratrons
Good bearing resolution largely depends upon: - CORRECT ANSWER✅✅A narrow antenna beam in the
horizontal plane
Bearing Resolution is: - CORRECT ANSWER✅✅The ability to distinguish two adjacent targets of equal
distance.
An artificial line is used for: - CORRECT ANSWER✅✅Determining the shape and durations of the pulses
What device is located between the magnetron and the mixer and prevents received signals from
entering the magnetron? - CORRECT ANSWER✅✅The ATR box
The ATR Box: - CORRECT ANSWER✅✅Prevents the received signal from entering the transmitter
When a pulse radar is radiating, which elements in the TR box are energized? - CORRECT
ANSWER✅✅The TR and ATR tubes
In the AFC system, the discriminator compares the frequencies of the: - CORRECT
ANSWER✅✅Magnetron and Klystron
The purpose of the discriminator circuit in a Radar is to: - CORRECT ANSWER✅✅Generate a corrective
voltage for controlling the frequency of the klystron local oscillator
Where is the RF Attenuator used in a Radar? - CORRECT ANSWER✅✅Between the Magnetron and AFC
section of the receiver
What frequency is the discriminator tuned to? - CORRECT ANSWER✅✅30 MHz IF
, The usual intermediate frequency of a shipboard Radar unit is: - CORRECT ANSWER✅✅30 or 60 MHz
The error voltage from the discriminator us applied to: - CORRECT ANSWER✅✅The repeller (reflector)
of the klystron
How may the frequency of the klystron be varied? - CORRECT ANSWER✅✅Small changes can be made
by adjusting the repeller voltage and large changes can be made by adjusting the size of the resonant
cavity
Fine adjustment of the reflex klystron are accomplished by: - CORRECT ANSWER✅✅Varing the repeller
voltage
The pulse repetition rate (PRR) refers to: - CORRECT ANSWER✅✅The pulse rate of the magnetron
The timer circuit: - CORRECT ANSWER✅✅Determines the PRR, determines range markers, and provides
blanking and unblanking signals for the CRT
On what frequency is radar expected to cause interference? - CORRECT ANSWER✅✅On most any
communication frequency
If the magnetron is allowed to operate without the magnetic field in place: - CORRECT ANSWER✅✅It
will quickly destroy itself from excessive current flow
What radar circuit determines the pulse repetition rate (PRR)? - CORRECT ANSWER✅✅The timer
(syncronizer circuit)
Range markers are determined by: - CORRECT ANSWER✅✅The timer
Unblanking pulses are produced by the timer circuit. Where are they sent? - CORRECT ANSWER✅✅To
the CRT
