Ship RADAR Endorsement
Marine RADAR theory, operation, maintenance, and troubleshooting including ARPA systems, target tracking, and collision avoidance.
Subelement A: RADAR Principles – 10 Key Topics – 10 Exam Questions – 8 Drawings
Topic 10: Circuits-2
In the circuit shown in Fig. 8A4, U5 pins 1 and 4 are high and both are in the reset state. Assume one clock cycle occurs of Clk A followed by one cycle of Clk B. What are the output states of the two D-type flip flops?
8-10A2If more light strikes the photodiode in Fig. 8A5, there will be:
8-10A3In the circuit shown in Fig. 8A6, which of the following is true?
8-10A4What is the correct value of RS in Fig. 8A7, if the voltage across the LED is 1.9 Volts with 5 Volts applied and If max equals 40 milliamps?
8-10A5The block diagram of a typical RADAR system microprocessor is shown in Fig. 8A2. Choose the most correct statement regarding this system.
8-10A6You are troubleshooting a component on a printed circuit board in a RADAR system while referencing the Truth Table in Fig. 8A8. What kind of integrated circuit is the component?
Topic 1: Marine RADAR Systems
Choose the most correct statement containing the parameters which control the size of the target echo.
8-1A2Which of the following has NO effect on the maximum range capability?
8-1A3What type of transmitter power is measured over a period of time?
8-1A4What RADAR component controls timing throughout the system?
8-1A5Which of the following components allows the use of a single antenna for both transmitting and receiving?
8-1A6The sweep frequency of a RADAR indicator is determined by what parameter?
Topic 2: Distance and Time
A radio wave will travel a distance of three nautical miles in:
8-2A2One RADAR mile is how many microseconds?
8-2A3RADAR range is measured by the constant:
8-2A4If a target is 5 miles away, how long does it take for the RADAR echo to be received back at the antenna?
8-2A5How long would it take for a RADAR pulse to travel to a target 10 nautical miles away and return to the RADAR receiver?
8-2A6What is the distance in nautical miles to a target if it takes 308.5 microseconds for the RADAR pulse to travel from the RADAR antenna to the target and back.
Topic 3: Frequency and Wavelength
Frequencies generally used for marine RADAR are in the ___ part of the radio spectrum.
8-3A2Practical RADAR operation requires the use of microwave frequencies so that:
8-3A3An S-band RADAR operates in which frequency band?
8-3A4A RADAR operating at a frequency of 3 GHz has a wavelength of approximately:
8-3A5The major advantage of an S-band RADAR over an X-band RADAR is:
8-3A6An X band RADAR operates in which frequency band?
Topic 4: Power, Pulse Width, PRR
A pulse RADAR has a pulse repetition frequency (PRF) of 400 Hz, a pulse width of 1 microsecond, and a peak power of 100 kilowatts. The average power of the RADAR transmitter is:
8-4A2A shipboard RADAR transmitter has a pulse repetition frequency (PRF) of 1,000 Hz, a pulse width of 0.5 microseconds, peak power of 150 KW, and a minimum range of 75 meters. Its duty cycle is:
8-4A3A pulse RADAR transmits a 0.5 microsecond RF pulse with a peak power of 100 kilowatts every 1600 microseconds. This RADAR has:
8-4A4If a RADAR transmitter has a pulse repetition frequency (PRF) of 900 Hz, a pulse width of 0.5 microseconds and a peak power of 15 kilowatts, what is its average power output?
8-4A5What is the average power if the RADAR set has a PRF of 1000 Hz, a pulse width of 1 microsecond, and a peak power rating of 100 kilowatts?
8-4A6A search RADAR has a pulse width of 1.0 microsecond, a pulse repetition frequency (PRF) of 900 Hz, and an average power of 18 watts. The unit’s peak power is:
Topic 5: Range, Pulse Width, PRF
For a range of 5 nautical miles, the RADAR pulse repetition frequency should be:
8-5A2For a range of 100 nautical miles, the RADAR pulse repetition frequency should be:
8-5A3The minimum range of a RADAR is determined by:
8-5A4Short range RADARs would most likely transmit:
8-5A5For a range of 30 nautical miles, the RADAR pulse repetition frequency should be:
8-5A6For a range of 10 nautical miles, the RADAR pulse repetition frequency (PRF) should be:
Topic 6: Pulse Width - Pulse Repetition Rates
If the PRF is 2500 Hz, what is the PRI?
8-6A2If the pulse repetition frequency (PRF) is 2000 Hz, what is the pulse repetition interval (PRI)?
8-6A3The pulse repetition rate (PRR) refers to:
8-6A4If the RADAR unit has a pulse repetition frequency (PRF) of 2000 Hz and a pulse width of 0.05 microseconds, what is the duty cycle?
8-6A5Small targets are best detected by:
8-6A6What is the relationship between pulse repetition rate and pulse width?
Topic 7: Components-1
What component of a RADAR receiver is represented by block 46 in Fig. 8A1?
8-7A2A basic sample-and-hold circuit contains:
8-7A3When comparing a TTL and a CMOS NAND gate:
8-7A4Silicon crystals:
8-7A5Which is typical current for a silicon crystal used in a RADAR mixer or detector circuit?
8-7A6What component of a RADAR receiver is represented by block 47 in Fig. 8A1?
Topic 8: Components-2
The basic frequency determining element in a Gunn oscillator is:
8-8A2Which of the following is not a method of analog-to-digital conversion?
8-8A3When comparing TTL and CMOS logic families, which of the following is true:
8-8A4The primary operating frequency of a reflex klystron is controlled by the:
8-8A5A Gunn diode oscillator takes advantage of what effect?
8-8A6Fine adjustments of a reflex klystron are accomplished by:
Topic 9: Circuits-1
Blocking oscillators operate on the formula of:
8-9A2The block diagram of a typical RADAR system microprocessor is shown in Fig. 8A2. Choose the most correct statement regarding this system.
8-9A3The phantastron circuit is capable of:
8-9A4The block diagram of a typical RADAR system microprocessor is shown in Fig. 8A2. Choose the most correct statement regarding this system.
8-9A5In the Line-Driver/Coax/Line-receiver circuit shown in Fig. 8A3, what component is represented by the blank box marked "X"?
8-9A6Choose the most correct statement:
Subelement B: Transmitting Systems – 8 Key Topics – 8 Exam Questions
Topic 11: Transmitting Systems
The magnetron is used to:
8-11B2The purpose of the modulator is to:
8-11B3Which of the following statements about most modern RADAR transmitter power supplies is false?
8-11B4The purpose of the Pulse Forming Network is to:
8-11B5The purpose of the Synchronizer is to:
8-11B6Which of the following is not part of the transmitting system?
Topic 12: Magnetrons
High voltage is applied to what element of the magnetron?
8-12B2The characteristic of the magnetron output pulse that relates to accurate range measurement is its:
8-12B3What device is used as a transmitter in a marine RADAR system?
8-12B4The magnetron is:
8-12B5A negative voltage is commonly applied to the magnetron cathode rather than a positive voltage to the magnetron anode because:
8-12B6The anode of a magnetron is normally maintained at ground potential:
Topic 13: Modulation
In a solid-state RADAR modulator, the duration of the transmitted pulse is determined by:
8-13B2The modulation frequency of most RADAR systems is between:
8-13B3A shipboard RADAR uses a PFN driving a magnetron cathode through a step-up transformer. This results in which type of modulation?
8-13B4In a pulse modulated magnetron what device determines the shape and width of the pulse?
8-13B5What device(s) may act as the modulator of a RADAR system?
8-13B6The purpose of a modulator in the transmitter section of a RADAR is to:
Topic 14: Pulse Forming Networks Modulation
The pulse developed by the modulator may have an amplitude greater than the supply voltage. This is possible by:
8-14B2Pulse transformers and pulse-forming networks are commonly used to shape the microwave energy burst RADAR transmitter. The switching devices most often used in such pulse-forming circuits are:
8-14B3The purpose of the pulse-forming network is to:
8-14B4The shape and duration of the high-voltage pulse delivered to the magnetron is established by:
8-14B5Pulse-forming networks are usually composed of the following:
8-14B6An artificial transmission line is used for:
Topic 15: TR - ATR - Circulators - Directional Couplers-1
The ferrite material in a circulator is used as a(an):
8-15B2In a circular resonant cavity with flat ends, the E-field and the H-field form with specific relationships. The:
8-15B3A ferrite circulator is most commonly used in what portion of a RADAR system?
8-15B4A circulator provides what function in the RF section of a RADAR system?
8-15B5A directional coupler has an attenuation of -30 db. A measurement of 100 milliwatts at the coupler indicates the power of the line is:
8-15B6What is the purpose or function of the RADAR duplexer/circulator?
Topic 16: TR - ATR - Circulators - Directional Couplers-2
The ATR box:
8-16B2When a pulse RADAR is radiating, which elements in the TR box are energized?
8-16B3The TR box:
8-16B4What device is located between the magnetron and the mixer and prevents received signals from entering the magnetron?
8-16B5A keep-alive voltage is applied to:
8-16B6A DC keep-alive potential:
Topic 17: Timer - Trigger - Synchronizer Circuits
What RADAR circuit determines the pulse repetition rate (PRR)?
8-17B2The triggering section is also known as the:
8-17B3Operation of any RADAR system begins in the:
8-17B4The timer circuit:
8-17B5Pulse RADARs require precise timing for their operation. Which type circuit below might best be used to provide these accurate timing pulses?
8-17B6Unblanking pulses are produced by the timer circuit. Where are they sent?
Topic 18: Power Supplies
An advantage of resonant charging is that it:
8-18B2The characteristics of a field-effect transistor (FET) used in a modern RADAR switching power supply can be compared as follows:
8-18B3A pulse-width modulator in a switching power supply is used to:
8-18B4In a fixed-frequency switching power supply, the pulse width of the switching circuit will increase when:
8-18B5A major consideration for the use of a switching regulator power supply over a linear regulator is:
8-18B6Which of the following characteristics are true of a power MOSFET used in a RADAR switching supply?
Subelement C: Receiving Systems – 10 Key Topics – 10 Exam Questions – 4 Drawings
Topic 19: Receiving Systems
Which of the following statements is true?
8-19C2Logarithmic receivers:
8-19C3RADAR receivers are similar to:
8-19C4What section of the receiving system sends signals to the display system?
8-19C5What is the main difference between an analog and a digital receiver?
8-19C6In a RADAR receiver, the RF power amplifier:
Topic 20: Mixers
The diagram in Fig. 8C9 shows a simplified RADAR mixer circuit using a crystal diode as the first detector. What is the output of the circuit when no echoes are being received?
8-20C2In the receive mode, frequency conversion is generally accomplished by a:
8-20C3An RF mixer has what purpose in a RADAR system?
8-20C4In a RADAR unit, the mixer uses a:
8-20C5What component of a RADAR receiver is represented by block 49 in Fig. 8A1?
8-20C6In a RADAR unit, the mixer uses:
Topic 21: Local Oscillators
The error voltage from the discriminator is applied to the:
8-21C2In a RADAR unit, the local oscillator is a:
8-21C3What component of a RADAR receiver is represented by block 48 in Fig. 8A1?
8-21C4What device(s) could be used as the local oscillator in a RADAR receiver?
8-21C5The klystron local oscillator is constantly kept on frequency by:
8-21C6How may the frequency of the klystron be varied?
Topic 22: Amplifiers
Overcoupling in a RADAR receiver will cause?
8-22C2The usual intermediate frequency of a shipboard RADAR unit is:
8-22C3The I.F. Amplifier bandwidth is:
8-22C4A logarithmic IF amplifier is preferable to a linear IF amplifier in a RADAR receiver because it:
8-22C5The high-gain IF amplifiers in a RADAR receiver may amplify a 2 microvolt input signal to an output level of 2 volts. This amount of amplification represents a gain of:
8-22C6In a RADAR receiver AGC and IAGC can vary between:
Topic 23: Detectors - Video Amplifiers
Which of the following statements is correct?
8-23C2Video amplifiers in pulse RADAR receivers must have a broad bandwidth because:
8-23C3In video amplifiers, compensation for the input and output stage capacitances must be accomplished to prevent distorting the video pulses. This compensation is normally accomplished by connecting:
8-23C4Which of the following signals is not usually an input to the video amplifier?
8-23C5Which of the following signals are usually an input to the video amplifier?
8-23C6The video (second) detector in a pulse modulated RADAR system would most likely use a/an:
Topic 24: Automatic Frequency Control - AFC
The AFC system is used to:
8-24C2A circuit used to develop AFC voltage in a RADAR receiver is called the:
8-24C3In the AFC system, the discriminator compares the frequencies of the:
8-24C4An AFC system keeps the receiver tuned to the transmitted signal by varying the frequency of the:
8-24C5A RADAR transmitter is operating on 3.0 GHz and the reflex klystron local oscillator, operating at 3.060 GHz, develops a 60 MHz IF. If the magnetron drifts higher in frequency, the AFC system must cause the klystron repeller plate to become:
8-24C6What component is block 50 in Fig. 8A1?
Topic 25: Sea Clutter - STC
The STC circuit is used to:
8-25C2The STC circuit:
8-25C3Sea return is:
8-25C4Sea clutter on the RADAR scope cannot be effectively reduced using front panel controls. What circuit would you suspect is faulty?
8-25C5What circuit controls the suppression of sea clutter?
8-25C6The sensitivity time control (STC) circuit:
Topic 26: Power Supplies
Prior to making “power-on” measurements on a switching power supply, you should be familiar with the supply because of the following:
8-26C2A constant frequency switching power supply regulator with an input voltage of 165 volts DC, and a switching frequency of 20 kHz, has an “ON” time of 27 microseconds when supplying 1 ampere to its load. What is the output voltage across the load?
8-26C3The circuit shown in Fig. 8C10 is the output of a switching power supply. Measuring from the junction of CR6, CR7 and L1 to ground with an oscilloscope, what waveform would you expect to see?
8-26C4With regard to the comparator shown in Fig. 8C11, the input is a sinusoid. Nominal high level output of the comparator is 4.5 volts. Choose the most correct statement regarding the input and output.
8-26C5When monitoring the gate voltage of a power MOSFET in the switching power supply of a modern RADAR, you would expect to see the gate voltage change from “low” to “high” by how much?
8-26C6The nominal output high of the comparator shown in Fig. 8C11 is 4.5 volts. Choose the most correct statement which describes the trip points.
Topic 27: Interference Issues
One of the best methods of reducing noise in a RADAR receiver is?
8-27C2The primary cause of noise in a RADAR receiver can be attributed to:
8-27C3Noise can appear on the LCD as:
8-27C4RADAR interference on a communications receiver appears as:
8-27C5In a RADAR receiver the most common types of interference are?
8-27C6Noise can:
Topic 28: Miscellaneous
The purpose of the discriminator circuit in a RADAR set is to:
8-28C2The MTI circuit:
8-28C3Where is a RF attenuator used in a RADAR unit?
8-28C4The condition known as “glint” refers to a shifting of clutter with each RADAR pulse and can be caused by a:
8-28C5An ion discharge (TR) cell is used to:
8-28C6When the receiver employs an MTI circuit:
Subelement D: Display & Control Systems - 10 Key Topics – 10 Exam Questions
Topic 29: Displays
Modern liquid crystal displays have a pixel count of:
8-29D2Voltages used in CRT anode circuits are in what range of value?
8-29D3The purpose of the aquadag coating on the CRT is:
8-29D4LCD patterns are formed when:
8-29D5In a raster-type display, the electron beam is scanned:
8-29D6Select the statement, which is most correct regarding a raster scan display.
Topic 30: Video Amplifiers and Sweep Circuits
What are the usual input signals to the video amplifier?
8-30D2Which of the following would not normally be an input to the video amplifier?
8-30D3The purpose of the sweep amplifier is to:
8-30D4How many deflection coils are driven by the sweep amplifier?
8-30D5The main purpose of the sweep generator is to provide:
8-30D6The main purpose of the video amplifier is to provide:
Topic 31: Timing Circuits
Timing circuits are used to provide what function?
8-31D2The circuit that develops timing signals is called the:
8-31D3Which of the following functions is not affected by the timing circuit?
8-31D4The synchronizer primarily affects the following circuit or function:
8-31D5The output from the synchronizer usually consists of a:
8-31D6The sweep drive is initiated by what circuit?
Topic 32: Fixed Range Markers
Accurate range markers must be developed using very narrow pulses. A circuit that could be used to provide these high-quality pulses for the CRT is a:
8-32D2Range markers are determined by:
8-32D3A gated LC oscillator, operating at 27 kHz, is being used to develop range markers. If each cycle is converted to a range mark, the range between markers will be:
8-32D4What would be the frequency of a range ring marker oscillator generating range rings at 10 nautical miles intervals?
8-32D5What is the distance between range markers if the controlling oscillator is operating at 20 kHz?
8-32D6What would be the frequency of a range ring marker oscillator generating range rings at intervals of 0.25 nautical miles?
Topic 33: Variable Range Markers
The variable range marker signal is normally fed to the input of the:
8-33D2The purpose of the variable range marker is to:
8-33D3How is the variable range marker usually adjusted for accuracy?
8-33D4The panel control for the variable range marker is normally a:
8-33D5An important component of the VRM system is the:
8-33D6Which of the following statements about the Variable Range Marker system is correct?
Topic 34: EBL, Azimuth and True Bearing
The purpose of the Electronic Bearing Line is to:
8-34D2The Electronic Bearing Line is:
8-34D3Which of the following inputs is required to indicate azimuth?
8-34D4Bearing information from the gyro is used to provide the following:
8-34D5Which of the following statements about “true bearing” is correct?
8-34D6A true bearing presentation appears as follows:
Topic 35: Memory Systems
In a digitized RADAR, the 360 degree sweep is divided into how many digitized segments?
8-35D2While troubleshooting a memory problem in a raster scan RADAR, you discover that the “REFRESH” cycle is not operating correctly. What type of memory circuit are you working on?
8-35D3The term DRAM stands for:
8-35D4How does the dual memory function reduce sea clutter?
8-35D5How many sequential memory cells with target returns are required to display the target?
8-35D6What is the primary purpose of display system memory?
Topic 36: ARPA - CAS
The ship’s speed indication on the ARPA display can be set manually, but does not change with changes in the vessel’s speed. What other indication would point to a related equipment failure?
8-36D2What does the term ARPA/CAS refer to?
8-36D3Which of the following would not be considered an input to the computer of a collision avoidance system?
8-36D4Which answer best describes a line on the display which indicates a target’s position. The speed is shown by the length of the line and the course by the direction of the line.
8-36D5What is the purpose or function of the “Trial Mode” used in most ARPA equipment?
8-36D6The ARPA term CPA refers to:
Topic 37: Display System Power Supplies
The display power supply provides the following:
8-37D2The display power supply provides the following:
8-37D3In a display system power supply what is the purpose of the chopper?
8-37D4In a display system power supply, what is the purpose of the inverter?
8-37D5What would be a common switching frequency for a display system power supply?
8-37D6What display system power supply output would use a tripler circuit?
Topic 38: Miscellaneous
The heading flash is a momentary intensification of the sweep line on the PPI presentation. Its function is to:
8-38D2The major advantage of digitally processing a RADAR signal is:
8-38D3In order to ensure that a practical filter is able to remove undesired components from the output of an analog-to-digital converter, the sampling frequency should be:
8-38D4Bearing resolution is:
8-38D5The output of an RC integrator, when driven by a square wave with a period of much less than one time constant is a:
8-38D6How do you eliminate stationary objects such as trees, buildings, bridges, etc., from the PPI presentation?
Subelement E: Antenna Systems- 5 Key Topics – 5 Exam Questions
Topic 39: Antenna Systems
Slotted waveguide arrays, when fed from one end exhibit:
8-39E2A typical shipboard RADAR antenna is a:
8-39E3Good bearing resolution largely depends upon:
8-39E4The center of the transmitted lobe from a slotted waveguide array is:
8-39E5How does antenna length affect the horizontal beamwidth of the transmitted signal?
8-39E6What is the most common type of RADAR antenna used aboard commercial maritime vessels?
Topic 40: Transmission Lines
The VSWR of a microwave transmission line device might be measured using:
8-40E2The impedance total (ZO) of a transmission line can be calculated by ZO = √L/C when L and C are known. When a section of transmission line contains 250 microhenries of L and 1000 picofarads of C, its impedance total (ZO) will be:
8-40E3If long-length transmission lines are not properly shielded and terminated:
8-40E4A certain length of transmission line has a characteristic impedance of 72 ohms. If the line is cut at its center, each half of the transmission line will have a ZO of:
8-40E5Standing waves on a transmission line may be an indication that:
8-40E6What precautions should be taken with horizontal waveguide runs?
Topic 41: Antenna to Display Interface
The position of the PPI scope sweep must indicate the position of the antenna. The sweep and antenna positions are frequently kept in synchronization by the use of:
8-41E2On a basic synchro system, the angular information is carried on the:
8-41E3What is the most common type of antenna position indicating device used in modern RADARs?
8-41E4Which of the following statements about antenna resolvers is correct?
8-41E5An antenna synchro transmitter is composed of the following:
8-41E6RADAR antenna direction must be sent to the display in all ARPAs or RADAR systems. How is this accomplished?
Topic 42: Waveguides-1
Waveguides can be constructed from:
8-42E2A microwave transmission line constructed of a center conductor suspended between parallel conductive ground planes is called:
8-42E3Waveguide theory is based upon:
8-42E4A waveguide is used at RADAR microwave frequencies because:
8-42E5Waveguide theory is based on the principals of:
8-42E6How is the signal removed from a waveguide or magnetron?
Topic 43: Waveguides-2
A rotary joint is used to:
8-43E2Resistive losses in a waveguide are very small because:
8-43E3A right-angle bend in an X-band waveguide must have a radius greater than:
8-43E4To insert RF energy into or extract RF energy from a waveguide, which of the following would not be used?
8-43E5The following is true concerning waveguides:
8-43E6At microwave frequencies, waveguides are used instead of conventional coaxial transmission lines because:
Subelement F: Installation, Maintenance & Repair
Topic 44: Equipment Faults-1
When you examine the RADAR you notice that there is no target video in the center of the CRT. The blank spot gets smaller in diameter as you increase the range scale. What operator front panel control could be misadjusted?
8-44F2Range rings on the PPI indicator are oval in shape. Which circuit would you suspect is faulty?
8-44F3What would be the most likely defective area when there is no target video in the center of the CRT and the blank spot gets smaller in diameter as your range scale is increased?
8-44F4While the vessel is docked the presentation of the pier is distorted near the center of the PPI with the pier appearing to bend in a concave fashion. This is a primary indication of what?
8-44F5In a RADAR using digital video processing, a bright, wide ring appears at a fixed distance from the center of the display on all digital ranges. The transmitter is operating normally. What receiver circuit would you suspect is causing the problem?
8-44F6The raster scan RADAR display has missing video in a rectangular block on the screen. Where is the most likely problem area?
Topic 45: Equipment Faults-2
A circuit card in a RADAR system has just been replaced with a spare card. You notice the voltage level at point E in Fig. 8F12 is negative 4.75 volts when the inputs are all at 5 volts. The problem is:
8-45F2A defective crystal in the AFC section will cause:
8-45F3The RADAR display has sectors of solid video (spoking). What would be the first thing to check?
8-45F4In the circuit contained in Fig. 8F12, there are 5 volts present at points B and C, and there are zero volts present at points A and D. What is the voltage at point E?
8-45F5If the TR tube malfunctions:
8-45F6The indicated distance from your own vessel to a lighthouse is found to be in error. What circuit would you suspect?
Topic 46: Equipment Faults-3
Silicon crystals are used in RADAR mixer and detector stages. Using an ohmmeter, how might a crystal be checked to determine if it is functional?
8-46F2In a RADAR unit, if the crystal mixer becomes defective, replace the:
8-46F3An increase in magnetron current that coincides with a decrease in power output is an indication of what?
8-46F4It is reported that the RADAR is not receiving small targets. The most likely causes are:
8-46F5A high magnetron current indicates a/an:
8-46F6Low or no mixer current could be caused by:
Topic 47: Equipment Faults-4
If the magnetron is allowed to operate without the magnetic field in place:
8-47F2Targets displayed on the RADAR display are not on the same bearing as their visual bearing. What should you first suspect?
8-47F3Loss of distant targets during and immediately after wet weather indicates:
8-47F4In a marine RADAR set, a high VSWR is indicated at the magnetron output. The waveguide and rotary joint appear to be functioning properly. What component may be malfunctioning?
8-47F5On a vessel with two RADARs, one has a different range indication on a specific target than the other. How would you determine which RADAR is incorrect?
8-47F6An increase in the deflection on the magnetron current meter could likely be caused by:
Topic 48: Maintenance
A thick layer of rust and corrosion on the surface of the parabolic dish will have what effect?
8-48F2The echo box is used for:
8-48F3What should be done to the interior surface of a waveguide in order to minimize signal loss?
8-48F4Which of the following is the most useful instrument for RADAR servicing?
8-48F5A non-magnetic screwdriver should always be used when replacing what component?
8-48F6What kind of display would indicate water in the waveguide?
Topic 49: Installation
Why is coaxial cable often used for S-band installations instead of a waveguide?
8-49F2RADAR interference to a communications receiver is eliminated by:
8-49F3Why should long horizontal runs of waveguide be avoided?
8-49F4Long horizontal sections of waveguides are not desirable because:
8-49F5In a RADAR system, waveguides should be installed:
8-49F6What is the most important factor to consider in locating the antenna?
Topic 50: Safety
Choose the most correct statement with respect to component damage from electrostatic discharge:
8-50F2Before testing a RADAR transmitter, it would be a good idea to:
8-50F3While making repairs or adjustments to RADAR units:
8-50F4While removing a CRT from its operating casing, it is a good idea to:
8-50F5If a CRT is dropped:
8-50F6Prior to removing, servicing or making measurements on any solid state circuit boards from the RADAR set, the operator should ensure that: