FCC Element 8 - Ship Radar, USCG prep certification 2026

Progress: 24% (23/94)

Learning progress ?

1. Choose the most correct statement containing the parameters which control the size of the target echo.Not learned 2. Which of the following has NO effect on the maximum range capability?Not learned 3. What type of transmitter power is measured over a period of time?Not learned 4. What RADAR component controls timing throughout the system?Not learned 5. Which of the following components allows the use of a single antenna for both transmitting and receiving?Not learned 6. The sweep frequency of a RADAR indicator is determined by what parameter?Not learned 7. A radio wave will travel a distance of three nautical miles in:Not learned 8. One RADAR mile is how many microseconds?Not learned 9. RADAR range is measured by the constant:Not learned 10. If a target is 5 miles away, how long does it take for the RADAR echo to be received back at the antenna?Not learned 11. How long would it take for a RADAR pulse to travel to a target 10 nautical miles away and return to the RADAR receiver?Not learned 12. What 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.Not learned 13. Frequencies generally used for marine RADAR are in the ___ part of the radio spectrum.Not learned 14. Practical RADAR operation requires the use of microwave frequencies so that:Not learned 15. An S-band RADAR operates in which frequency band?Not learned 16. A RADAR operating at a frequency of 3 GHz has a wavelength of approximately:Not learned 17. The major advantage of an S-band RADAR over an X-band RADAR is:Not learned 18. An X band RADAR operates in which frequency band?Not learned 19. 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:Not learned 20. A 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:Not learned 21. A pulse RADAR transmits a 0.5 microsecond RF pulse with a peak power of 100 kilowatts every 1600 microseconds. This RADAR has:Not learned 22. If 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?Not learned 23. What 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?Not learned 24. A 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:Not learned 25. For a range of 5 nautical miles, the RADAR pulse repetition frequency should be:Not learned 26. For a range of 100 nautical miles, the RADAR pulse repetition frequency should be:Not learned 27. The minimum range of a RADAR is determined by:Not learned 28. Short range RADARs would most likely transmit:Not learned 29. For a range of 30 nautical miles, the RADAR pulse repetition frequency should be:Not learned 30. For a range of 10 nautical miles, the RADAR pulse repetition frequency (PRF) should be:Not learned 31. If the PRF is 2500 Hz, what is the PRI?Not learned 32. If the pulse repetition frequency (PRF) is 2000 Hz, what is the pulse repetition interval (PRI)?Not learned 33. The pulse repetition rate (PRR) refers to:Not learned 34. If 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?Not learned 35. Small targets are best detected by:Not learned 36. What is the relationship between pulse repetition rate and pulse width?Not learned 37. What component of a RADAR receiver is represented by block 46 in Fig. 8A1?Not learned 38. A basic sample-and-hold circuit contains:Not learned 39. When comparing a TTL and a CMOS NAND gate:Not learned 40. Silicon crystals:Not learned 41. Which is typical current for a silicon crystal used in a RADAR mixer or detector circuit?Not learned 42. What component of a RADAR receiver is represented by block 47 in Fig. 8A1?Not learned 43. The basic frequency determining element in a Gunn oscillator is:Not learned 44. Which of the following is not a method of analog-to-digital conversion?Not learned 45. When comparing TTL and CMOS logic families, which of the following is true:Not learned 46. The primary operating frequency of a reflex klystron is controlled by the:Not learned 47. A Gunn diode oscillator takes advantage of what effect?Not learned 48. Fine adjustments of a reflex klystron are accomplished by:Not learned 49. Blocking oscillators operate on the formula of:Not learned 50. The block diagram of a typical RADAR system microprocessor is shown in Fig. 8A2. Choose the most correct statement regarding this system.Not learned 51. The phantastron circuit is capable of:Not learned 52. The block diagram of a typical RADAR system microprocessor is shown in Fig. 8A2. Choose the most correct statement regarding this system.Not learned 53. In the Line-Driver/Coax/Line-receiver circuit shown in Fig. 8A3, what component is represented by the blank box marked "X"?Not learned 54. Choose the most correct statement:Not learned 55. 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?Not learned 56. If more light strikes the photodiode in Fig. 8A5, there will be:Not learned 57. In the circuit shown in Fig. 8A6, which of the following is true?Not learned 58. What 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?Not learned 59. The block diagram of a typical RADAR system microprocessor is shown in Fig. 8A2. Choose the most correct statement regarding this system.Not learned 60. You 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?Not learned 61. The magnetron is used to:Not learned 62. The purpose of the modulator is to:Not learned 63. Which of the following statements about most modern RADAR transmitter power supplies is false?Not learned 64. The purpose of the Pulse Forming Network is to:Not learned 65. The purpose of the Synchronizer is to:Not learned 66. Which of the following is not part of the transmitting system?Not learned 67. High voltage is applied to what element of the magnetron?Not learned 68. The characteristic of the magnetron output pulse that relates to accurate range measurement is its:Not learned 69. What device is used as a transmitter in a marine RADAR system?Not learned 70. The magnetron is:Not learned 71. A negative voltage is commonly applied to the magnetron cathode rather than a positive voltage to the magnetron anode because:Not learned 72. The anode of a magnetron is normally maintained at ground potential:Not learned 73. In a solid-state RADAR modulator, the duration of the transmitted pulse is determined by:Not learned 74. The modulation frequency of most RADAR systems is between:Not learned 75. A shipboard RADAR uses a PFN driving a magnetron cathode through a step-up transformer. This results in which type of modulation?Not learned 76. In a pulse modulated magnetron what device determines the shape and width of the pulse?Not learned 77. What device(s) may act as the modulator of a RADAR system?Not learned 78. The purpose of a modulator in the transmitter section of a RADAR is to:Not learned 79. The pulse developed by the modulator may have an amplitude greater than the supply voltage. This is possible by:Not learned 80. Pulse 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:Not learned 81. The purpose of the pulse-forming network is to:Not learned 82. The shape and duration of the high-voltage pulse delivered to the magnetron is established by:Not learned 83. Pulse-forming networks are usually composed of the following:Not learned 84. An artificial transmission line is used for:Not learned 85. The ferrite material in a circulator is used as a(an):Not learned 86. In a circular resonant cavity with flat ends, the E-field and the H-field form with specific relationships. The:Not learned 87. A ferrite circulator is most commonly used in what portion of a RADAR system?Not learned 88. A circulator provides what function in the RF section of a RADAR system?Not learned 89. A directional coupler has an attenuation of -30 db. A measurement of 100 milliwatts at the coupler indicates the power of the line is:Not learned 90. What is the purpose or function of the RADAR duplexer/circulator?Not learned 91. The ATR box:Not learned 92. When a pulse RADAR is radiating, which elements in the TR box are energized?Not learned 93. The TR box:Not learned 94. What device is located between the magnetron and the mixer and prevents received signals from entering the magnetron?Not learned 95. A keep-alive voltage is applied to:Not learned 96. A DC keep-alive potential:Not learned 97. What RADAR circuit determines the pulse repetition rate (PRR)?Not learned 98. The triggering section is also known as the:Not learned 99. Operation of any RADAR system begins in the:Not learned 100. The timer circuit:Not learned 101. Pulse RADARs require precise timing for their operation. Which type circuit below might best be used to provide these accurate timing pulses?Not learned 102. Unblanking pulses are produced by the timer circuit. Where are they sent?Not learned 103. An advantage of resonant charging is that it:Not learned 104. The characteristics of a field-effect transistor (FET) used in a modern RADAR switching power supply can be compared as follows:Not learned 105. A pulse-width modulator in a switching power supply is used to:Not learned 106. In a fixed-frequency switching power supply, the pulse width of the switching circuit will increase when:Not learned 107. A major consideration for the use of a switching regulator power supply over a linear regulator is:Not learned 108. Which of the following characteristics are true of a power MOSFET used in a RADAR switching supply?Not learned 109. Which of the following statements is true?Not learned 110. Logarithmic receivers:Not learned 111. RADAR receivers are similar to:Not learned 112. What section of the receiving system sends signals to the display system?Not learned 113. What is the main difference between an analog and a digital receiver?Not learned 114. In a RADAR receiver, the RF power amplifier:Not learned 115. 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?Not learned 116. In the receive mode, frequency conversion is generally accomplished by a:Not learned 117. An RF mixer has what purpose in a RADAR system?Not learned 118. In a RADAR unit, the mixer uses a:Not learned 119. What component of a RADAR receiver is represented by block 49 in Fig. 8A1?Not learned 120. In a RADAR unit, the mixer uses:Not learned 121. The error voltage from the discriminator is applied to the:Not learned 122. In a RADAR unit, the local oscillator is a:Not learned 123. What component of a RADAR receiver is represented by block 48 in Fig. 8A1?Not learned 124. What device(s) could be used as the local oscillator in a RADAR receiver?Not learned 125. The klystron local oscillator is constantly kept on frequency by:Not learned 126. How may the frequency of the klystron be varied?Not learned 127. Overcoupling in a RADAR receiver will cause?Not learned 128. The usual intermediate frequency of a shipboard RADAR unit is:Not learned 129. The I.F. Amplifier bandwidth is:Not learned 130. A logarithmic IF amplifier is preferable to a linear IF amplifier in a RADAR receiver because it:Not learned 131. The 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:Not learned 132. In a RADAR receiver AGC and IAGC can vary between:Not learned 133. Which of the following statements is correct?Not learned 134. Video amplifiers in pulse RADAR receivers must have a broad bandwidth because:Not learned 135. In 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:Not learned 136. Which of the following signals is not usually an input to the video amplifier?Not learned 137. Which of the following signals are usually an input to the video amplifier?Not learned 138. The video (second) detector in a pulse modulated RADAR system would most likely use a/an:Not learned 139. The AFC system is used to:Not learned 140. A circuit used to develop AFC voltage in a RADAR receiver is called the:Not learned 141. In the AFC system, the discriminator compares the frequencies of the:Not learned 142. An AFC system keeps the receiver tuned to the transmitted signal by varying the frequency of the:Not learned 143. A 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:Not learned 144. What component is block 50 in Fig. 8A1?Not learned 145. The STC circuit is used to:Not learned 146. The STC circuit:Not learned 147. Sea return is:Not learned 148. Sea clutter on the RADAR scope cannot be effectively reduced using front panel controls. What circuit would you suspect is faulty?Not learned 149. What circuit controls the suppression of sea clutter?Not learned 150. The sensitivity time control (STC) circuit:Not learned 151. Prior to making "power-on" measurements on a switching power supply, you should be familiar with the supply because of the following:Not learned 152. A 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?Not learned 153. The 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?Not learned 154. With 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.Not learned 155. When 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?Not learned 156. The nominal output high of the comparator shown in Fig. 8C11 is 4.5 volts. Choose the most correct statement which describes the trip points.Not learned 157. One of the best methods of reducing noise in a RADAR receiver is?Not learned 158. The primary cause of noise in a RADAR receiver can be attributed to:Not learned 159. Noise can appear on the LCD as:Not learned 160. RADAR interference on a communications receiver appears as:Not learned 161. In a RADAR receiver the most common types of interference are?Not learned 162. Noise can:Not learned 163. The purpose of the discriminator circuit in a RADAR set is to:Not learned 164. The MTI circuit:Not learned 165. Where is a RF attenuator used in a RADAR unit?Not learned 166. The condition known as "glint" refers to a shifting of clutter with each RADAR pulse and can be caused by a:Not learned 167. An ion discharge (TR) cell is used to:Not learned 168. When the receiver employs an MTI circuit:Not learned 169. Modern liquid crystal displays have a pixel count of:Not learned 170. Voltages used in CRT anode circuits are in what range of value?Not learned 171. The purpose of the aquadag coating on the CRT is:Not learned 172. LCD patterns are formed when:Not learned 173. In a raster-type display, the electron beam is scanned:Not learned 174. Select the statement, which is most correct regarding a raster scan display.Not learned 175. What are the usual input signals to the video amplifier?Not learned 176. Which of the following would not normally be an input to the video amplifier?Not learned 177. The purpose of the sweep amplifier is to:Not learned 178. How many deflection coils are driven by the sweep amplifier?Not learned 179. The main purpose of the sweep generator is to provide:Not learned 180. The main purpose of the video amplifier is to provide:Not learned 181. Timing circuits are used to provide what function?Not learned 182. The circuit that develops timing signals is called the:Not learned 183. Which of the following functions is not affected by the timing circuit?Not learned 184. The synchronizer primarily affects the following circuit or function:Not learned 185. The output from the synchronizer usually consists of a:Not learned 186. The sweep drive is initiated by what circuit?Not learned 187. 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:Not learned 188. Range markers are determined by:Not learned 189. A 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:Not learned 190. What would be the frequency of a range ring marker oscillator generating range rings at 10 nautical miles intervals?Not learned 191. What is the distance between range markers if the controlling oscillator is operating at 20 kHz?Not learned 192. What would be the frequency of a range ring marker oscillator generating range rings at intervals of 0.25 nautical miles?Not learned 193. The variable range marker signal is normally fed to the input of the:Not learned 194. The purpose of the variable range marker is to:Not learned 195. How is the variable range marker usually adjusted for accuracy?Not learned 196. The panel control for the variable range marker is normally a:Not learned 197. An important component of the VRM system is the:Not learned 198. Which of the following statements about the Variable Range Marker system is correct?Not learned 199. The purpose of the Electronic Bearing Line is to:Not learned 200. The Electronic Bearing Line is:Not learned 201. Which of the following inputs is required to indicate azimuth?Not learned 202. Bearing information from the gyro is used to provide the following:Not learned 203. Which of the following statements about "true bearing" is correct?Not learned 204. A true bearing presentation appears as follows:Not learned 205. In a digitized RADAR, the 360 degree sweep is divided into how many digitized segments?Not learned 206. While 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?Not learned 207. The term DRAM stands for:Not learned 208. How does the dual memory function reduce sea clutter?Not learned 209. How many sequential memory cells with target returns are required to display the target?Not learned 210. What is the primary purpose of display system memory?Not learned 211. 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?Not learned 212. What does the term ARPA/CAS refer to?Not learned 213. Which of the following would not be considered an input to the computer of a collision avoidance system?Not learned 214. Which 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.Not learned 215. What is the purpose or function of the "Trial Mode" used in most ARPA equipment?Not learned 216. The ARPA term CPA refers to:Not learned 217. The display power supply provides the following:Not learned 218. The display power supply provides the following:Not learned 219. In a display system power supply what is the purpose of the chopper?Not learned 220. In a display system power supply, what is the purpose of the inverter?Not learned 221. What would be a common switching frequency for a display system power supply?Not learned 222. What display system power supply output would use a tripler circuit?Not learned 223. The heading flash is a momentary intensification of the sweep line on the PPI presentation. Its function is to:Not learned 224. The major advantage of digitally processing a RADAR signal is:Not learned 225. In 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:Not learned 226. Bearing resolution is:Not learned 227. The output of an RC integrator, when driven by a square wave with a period of much less than one time constant is a:Not learned 228. How do you eliminate stationary objects such as trees, buildings, bridges, etc., from the PPI presentation?Not learned 229. Slotted waveguide arrays, when fed from one end exhibit:Not learned 230. A typical shipboard RADAR antenna is a:Not learned 231. Good bearing resolution largely depends upon:Not learned 232. The center of the transmitted lobe from a slotted waveguide array is:Not learned 233. How does antenna length affect the horizontal beamwidth of the transmitted signal?Not learned 234. What is the most common type of RADAR antenna used aboard commercial maritime vessels?Not learned 235. The VSWR of a microwave transmission line device might be measured using:Not learned 236. The 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:Not learned 237. If long-length transmission lines are not properly shielded and terminated:Not learned 238. A 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:Not learned 239. Standing waves on a transmission line may be an indication that:Not learned 240. What precautions should be taken with horizontal waveguide runs?Not learned 241. 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:Not learned 242. On a basic synchro system, the angular information is carried on the:Not learned 243. What is the most common type of antenna position indicating device used in modern RADARs?Not learned 244. Which of the following statements about antenna resolvers is correct?Not learned 245. An antenna synchro transmitter is composed of the following:Not learned 246. RADAR antenna direction must be sent to the display in all ARPAs or RADAR systems. How is this accomplished?Not learned 247. Waveguides can be constructed from:Not learned 248. A microwave transmission line constructed of a center conductor suspended between parallel conductive ground planes is called:Not learned 249. Waveguide theory is based upon:Not learned 250. A waveguide is used at RADAR microwave frequencies because:Not learned 251. Waveguide theory is based on the principals of:Not learned 252. How is the signal removed from a waveguide or magnetron?Not learned 253. A rotary joint is used to:Not learned 254. Resistive losses in a waveguide are very small because:Not learned 255. A right-angle bend in an X-band waveguide must have a radius greater than:Not learned 256. To insert RF energy into or extract RF energy from a waveguide, which of the following would not be used?Not learned 257. The following is true concerning waveguides:Not learned 258. At microwave frequencies, waveguides are used instead of conventional coaxial transmission lines because:Not learned 259. 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?Not learned 260. Range rings on the PPI indicator are oval in shape. Which circuit would you suspect is faulty?Not learned 261. What 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?Not learned 262. While 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?Not learned 263. In 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?Not learned 264. The raster scan RADAR display has missing video in a rectangular block on the screen. Where is the most likely problem area?Not learned 265. 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:Not learned 266. A defective crystal in the AFC section will cause:Not learned 267. The RADAR display has sectors of solid video (spoking). What would be the first thing to check?Not learned 268. In 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?Not learned 269. If the TR tube malfunctions:Not learned 270. The indicated distance from your own vessel to a lighthouse is found to be in error. What circuit would you suspect?Not learned 271. 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?Not learned 272. In a RADAR unit, if the crystal mixer becomes defective, replace the:Not learned 273. An increase in magnetron current that coincides with a decrease in power output is an indication of what?Not learned 274. It is reported that the RADAR is not receiving small targets. The most likely causes are:Not learned 275. A high magnetron current indicates a/an:Not learned 276. Low or no mixer current could be caused by:Not learned 277. If the magnetron is allowed to operate without the magnetic field in place:Not learned 278. Targets displayed on the RADAR display are not on the same bearing as their visual bearing. What should you first suspect?Not learned 279. Loss of distant targets during and immediately after wet weather indicates:Not learned 280. In 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?Not learned 281. On 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?Not learned 282. An increase in the deflection on the magnetron current meter could likely be caused by:Not learned 283. A thick layer of rust and corrosion on the surface of the parabolic dish will have what effect?Not learned 284. The echo box is used for:Not learned 285. What should be done to the interior surface of a waveguide in order to minimize signal loss?Not learned 286. Which of the following is the most useful instrument for RADAR servicing?Not learned 287. A non-magnetic screwdriver should always be used when replacing what component?Not learned 288. What kind of display would indicate water in the waveguide?Not learned 289. Why is coaxial cable often used for S-band installations instead of a waveguide?Not learned 290. RADAR interference to a communications receiver is eliminated by:Not learned 291. Why should long horizontal runs of waveguide be avoided?Not learned 292. Long horizontal sections of waveguides are not desirable because:Not learned 293. In a RADAR system, waveguides should be installed:Not learned 294. What is the most important factor to consider in locating the antenna?Not learned 295. Choose the most correct statement with respect to component damage from electrostatic discharge:Not learned 296. Before testing a RADAR transmitter, it would be a good idea to:Not learned 297. While making repairs or adjustments to RADAR units:Not learned 298. While removing a CRT from its operating casing, it is a good idea to:Not learned 299. If a CRT is dropped:Not learned 300. Prior to removing, servicing or making measurements on any solid state circuit boards from the RADAR set, the operator should ensure that:Not learned