Analysis, modelling and measurement of the effects of aluminium and polymer heatsinks on conducted electromagnetic compatibility in DC–DC converters   
Effects of polymer heatsink materials on electromagnetic interference (EMI) noise in converters have not been adequately investigated. Heatsinks provide a path to ground for the common-mode (CM) noise. Selecting an appropriate heatsink material can therefore help reduce CM noise by increasing noise path impedance. The critical parameter is the heatsink-to-device capacitance and accurate models of the heatsink impedance need to be developed. This is necessary for results that are accurate enough to allow prequalification of a converter as would happen in an accredited environment. However, simplified CM and differential-mode models of the step-down DC–DC converter are adequate to predict the effects of the heatsink on the conducted noise. This study will demonstrate that compared to a solid aluminium material, using polymer material incorporating conductive fillers can greatly lower the device-to-heatsink capacitance, and still be adequate for heat dissipation in low power converters. This in turn reduces CM noise in the frequency band below 30 MHz. The measurement test setup is configured according to MIL-STD-461F standard. It consists of a wideband two-port line impedance stabilising network (LISN), a properly grounded copper sheet, a suspended feed-line from the LISN to the device under test and an oscilloscope recording the data.
          EEVblog #1004 – Owon XDS3202A 14bit Oscilloscope Teardown   
EEVblog #1004 – Owon XDS3202A 14bit Oscilloscope TeardownBy EEVblog >> WATCH HERE << Watch it here >>> : https://www.youtube.com/watch?v=-F4H-zC_i0s
          Controls Field Service Technician - National Oilwell Varco - Oklahoma City, OK   
Ability to utilize various electrical diagnostic tools including multimeters, oscilloscope, and basic hand tools....
From National Oilwell Varco - Fri, 30 Jun 2017 03:28:42 GMT - View all Oklahoma City, OK jobs
          (USA-TN-Monterey) Maintenance Controls & Automation Supervisor   
**Company Overview** **:** We are Kerry. The Taste & Nutrition Company. We make products people enjoy and feel better about. And, we are growing. We need talented, passionate people who want to help us make the business better. People who expect better from themselves. People who care about delivering better for customers, their colleagues, the company and their own career. People who take pride in paving new paths to lead the business forward. We need great people who want to do great things. People like you, perhaps. If you are high energy, self-motivated, creative, collaborative, and enjoy executing against the demands of a fast-paced high growth organization, then consider joining our team to help drive your career and Kerry forward. Learn more and/or apply at . Kerry is an Equal Opportunity Employer. Employment decisions are made without regard to race, color, religion, national or ethnic origin, sex, sexual orientation, gender identity or expression, age, disability, protected veteran status or other characteristics. **Description and Responsibilities** **:** OurCrossville, TN, plant is growing, and looking for a motivated Maintenance Controls & Automation Supervisor to join the team! With over 41 plants across North America, our Crossville facility is a part of our meat division, and has around 50 employees at the plant. Hours are 8:00-4:00pm CST. So if you are looking to join a growing organization that offers career advancement, cutting edge food processing technologies, and the chance to work with a global organization, then this could be the right opportunity for you! Responsibilities include: + Install, service, troubleshoot and preform preventive and predictive maintenance functions of the electrical and automation control systems. + Various project responsibilities + Other duties as assigned **Qualifications** **:** + Must be knowledgeable in the use of multi-meters, oscilloscopes, PCs, and other test equipment. + Must have a general maintenance knowledge and ability to work in any area including helping a mechanic or performing mechanic duties. + Must possess an understanding of electricity, electrical systems, electrical motor control systems, and process control instrumentation. This includes, but is not limited to 480 Volt 3 Phase motor switchgear, 120 Volt control systems, PLC systems, and 4-20ma analog instrumentation. + Must have basic knowledge of testing and working with electrical switching devices such as starters, relays, timers, and solenoids. + Knowledge of discrete I/O devices such as pressure and limit switches. + Must have understanding of analog instrumentation, PID control, PLCs and Ladder Logic. + Ability to operate and understand computer hardware and software as it relates to the operation and control of this process. + Possess good communication, teamwork, and interpersonal skills + Food industry or similar experience is preferred + Constant learning may be required to keep up with new technology + 4 year degree in Engineering Technology required + Minimum of 3-5 years’ experience as Instrumentation and Electrical Controls required **Requisition ID** _2017-9166_ **Division** _Kerry_ **Job Locations** _US-TN-Monterey_ **Position Type** _Full Time_ **Recruiter** _KW1_ **Posting Type** _LI_
          Communications Engineering Mastery Test 7: ECE Pre-Board   

Communications Engineering Exam 7

This is 100 items set of Practice Examination 7 in Communications Engineering (Electronics Systems and Technology) composed of previous Board Exams Questions. Read each questions and choices carefully! Choose the best answer. In the actual board, you have to answer 100 items in Communications Engineering within 5 hours. You have to get at least 70% to pass the subject. Communications Engineering is 30% of the total 100% Board Rating along with Mathematics (20%), General Engineering and Applied Sciences (20%) and Electronics Engineering (30%). Familiarize each and every questions to increase the chance of passing the ECE Board Examination.

Start the Test Yourself Exam 7

Choose the letter of the best answer in each questions.

1. How far away is the radio horizon of an antenna 100 ft high?

  • A. 14.14 mi
  • B. 40km
  • C. 14.14 km
  • D. 40 mi

2. What is the maximum line-of-sight distance between a paging antenna 250 ft high and a pager receiver 3.5 ft of the ground?

  • A. 25 km
  • B. 25 mi
  • C. 70.73 km
  • D. 70.73 mi

3. What is the path attenuation between transmitter and receiver at a frequency of 1.2 Ghz and a distance of 11,000 mi?

  • A. 119 dB
  • B. 115 dB
  • C. 179 dB
  • D. 174 dB

4. What is the uplink receiver frequency if the downlink transmitter is on channel 4 (3.84 Ghz)?

  • A. 6.065 GHz
  • B. 6.84 GHz
  • C. 6.65 GHz
  • D. 6.05 GHz

5. What is the maximum theoretical data rate of the above problem if one transponder is used for binary transmission?

  • A. 36 Mbps
  • B. 72 Mbps
  • C.18 Mbps
  • D. 144 Mbps

6. What is the guardband between transponder channels in the commercial C-band for satellite communications?

  • A. 6 MHz
  • B. 36 MHz
  • C. 4 MHz
  • D. 2 MHz

7. What is the typical satellite transponder bandwidth?

  • A. 24 MHz
  • B. 500 MHz
  • C. 36 MHz
  • D. 48 MHz

8. What is the bandwidth available in the commercial C-band?

  • A. 1000 MHz
  • B. 36 MHz
  • C. 250 MHz
  • D. 500 MHz

9. Which of the following is the uplink frequency in C-band?

  • A. 5.925 GHz
  • B. 4.2 GHz
  • C. 7.425 GHz
  • D. 3.7 GHz

10. How many transponder channels are realized in the commercial C-band without frequency re-use?

  • A. 24
  • B. 12
  • C. 36
  • D. 48

11. Which band of frequencies used by military for its satellites and radar?

  • A. C band
  • B. X band
  • C. L band
  • D. P band

12. For navigation as well as marine and aeronautical communications and radar, ____ band is used.

  • A. L
  • B. K
  • C. S
  • D. J

13. What is the current frequency band given most attenuation for satellite communications?

  • A. Ku
  • B. C band
  • C. J
  • D. P

14. What satellite subsystem monitors onboard conditions such as temperature and battery voltage and transmits this data back to a ground station for analysis?

  • A. Communications subsystem
  • B. AKM
  • C. TTC
  • D. Transponder

15. Which of the following satellite subsystem provides stabilization in orbit and senses changes in orientation?

  • A. Attitude control subsystem
  • B. TTC
  • C. AKM
  • D. Transponder

16. What is the typical center frequency spacing between adjacent channels (transponders) in satellites?

  • A. 36 MHz
  • B. 40 MHz
  • C. 500 MHz
  • D. 4 MHz

17. Which of the following are uplinks in the Ku band?

  • A. 14 to 14.5 GHz
  • B. 11.7 to 12.2 GHz
  • C. 14 to 15.5 GHz
  • D. 11 to 11.5 GHz

18. What is considered as the most advanced satellite system developed for cellular telephones?

  • A. Iridium
  • B. Globalstar
  • C. ANIK
  • D. Molniya

19. What is the orbit of Motorola’s Iridium satellite system?

  • A. Polar
  • B. Equatorial
  • C. Inclined elliptical
  • D. Inclined equatorial

20. What band of frequencies do these satellites operate?

  • A. L band
  • B. Ka band
  • C. C band
  • D. Ku band

21. Iridium satellites can provide data communications of up ____ bps data rate.

  • A. 1200
  • B. 4800
  • C. 2400
  • D. 3840

22. What satellite system is also known as Navstar?

  • A. GPS
  • B. Iridium
  • C. Globalstar
  • D. Intelsat

23. What is the orbit height of a GPS satellite?

  • A. 10,898 nmi
  • B. 10,898 mi
  • C. 10,898 km
  • D. 10, 898 m

24. What is the orbital period of each satellite in the GPS constellation?

  • A. 6 h
  • B. 12 h
  • C. 5 h
  • D. 15 h

25. What term is normally associated with specifying the location of a celestial body in space?

  • A. Constellation
  • B. Galaxy
  • C. Satellite
  • D. Ephemeris

26. What is the angle of inclination of GPS system?

  • A. 55˚
  • B. 65˚
  • C. 105˚
  • D. 45˚

27. What material is most often used for the outer covering of coaxial cables?

  • A. PVC
  • B. Teflon
  • C. PE
  • D. Polystyrene

28. What is the dielectric constant of polyethylene (PE) insulator?

  • A. 2.5
  • B. 3.3
  • C. 2.27
  • D. 2.1

29. Polytetrafluoroethylene (PTFE) is also widely used insulator and is known as.

  • A. polystyrene
  • B. teflon
  • C. ceramic
  • D. bakelite

30. What is the characteristic impedance of a two-wire line with the following data: diameter = 0.023in., spacing =0.5 in., insulation = PE.?

  • A. 300 Ω
  • B. 250 Ω
  • C. 305 Ω
  • D. 301 Ω

31. What is the characteristic impedance of a coaxial line with the following data: inner diameter = 0.2 in., center conductor diameter = 0.06 in., insulation = Teflon.

  • A. 200 Ω
  • B. 75 Ω
  • C. 50 Ω
  • D. 150 Ω

32. A pair of current-carrying conductors is not considered a transmission line unless it is at least ___ λ long at the signal frequency.

  • A. 0.1
  • B. 0.3
  • C. 0.2
  • D. 0.4

33. If the operating frequency is 450 MHz what length of a pair of conductors is considered to be a transmission line?

  • A. 2.19 ft
  • B. 2.19 m
  • C. 0.219 ft
  • D. 0.219 m

34. What is the physical length of the above transmission line at 3/8λ long?

  • A.0.82 m
  • B. 0.82 ft
  • C. 0.82 in
  • D. 0.82 cm

35. Which of the following coaxial cable connectors is called the UHF connector?

  • A. PL-259
  • B. BNC
  • C. N-type connector
  • D. F connector

36. What connector is popular in attaching test instruments like oscilloscopes, frequency counters, spectrum analyzers, etc?

  • A. UHF connector
  • B. PL-259
  • C. BNC
  • D. SMA

37. Which coaxial cable connector is least expensive and is widely used for TV sets,VCRs and cable TV?

  • A. N-type connector
  • B. F-type connector
  • C. BNC
  • D. PL-259

38. Which coaxial connector is a more complex and expensive but do a better job in maintaining the electrical characteristics of the cable through the interconnections?

  • A. N-type connector
  • B. F-type connector
  • C.BNC
  • D. PL-259

39. The velocity factor in transmission lines vary from ___ to ___.

  • A. 0.6 to 0.8
  • B. 0.3 to 0.5
  • C.0.5 to 0.9
  • D. 0.8 to 0.9

40. What is the typical velocity factor of coaxial cables?

  • A. 0.6 to 0.8
  • B. 0.3 to 0.5
  • C. 0.5 to 0.9
  • D. 0.4 to 0.6

41. What is the typical velocity factor of open-wire line?

  • A. 0.9
  • B. 0.8
  • C. 0.5
  • D. 0.7

42. What line has a typical velocity factor of about 0.8?

  • A. Shielded pair
  • B. Flexible coaxial
  • C. Twin-lead
  • D. Open-wire line

43. What is the velocity factor of coaxial cable with a characteristic impedance of 50 Ω and capacitance of 30 pF/ft and inductance of 75 nH/ft?

  • A. 0.58
  • B.0.68
  • C. 0.98
  • D. 0.81

44. What is transit time (time delay) of a 50-ft length transmission line of the above problem?

  • A. 50 ns
  • B. 100 ns
  • C. 75 ns
  • D. 65 ns

45. What do you call a transmission line used specifically for the purpose of achieving delay?

  • A. Delay line
  • B. Flat line
  • C. Resonant line
  • D. Non-resonant line

46. What is the time delay introduced by a 75-ft coaxial cable with a dielectric constant of 2.3?

  • A. 1.54 ns
  • B. 11.5 ns
  • C. 115.6 ns
  • D. 1156 ns

47. Assume a frequency of 4 MHz, determine the phase shift offered by the line in the above problem.

  • A. 108.5˚
  • B. 106.5˚
  • C. 115.5˚
  • D. 166.5˚

48. Find the load impedance that must be used to terminate RG-62A/U to avoid reflections?

  • A. 93 Ω
  • B. 75 Ω
  • C. 50 Ω
  • D. 300 Ω

49. Find the equivalent inductance per foot of the above cable?

  • A. 13.5 nF/ft
  • B. 13.5 pF/ft
  • C. 116.8 nH/ft
  • D. 116.8 pF/ft

50. An RG-11/U foam coaxial cable has a maximum voltage standing wave of 52 V and a minimum voltage of 17 V. Find the value of the resistive load.

  • A. 24.59Ω
  • B. Either A or C
  • C. 228.75Ω
  • D. Neither A nor C

51. Sound provides all sorts of information. What information is related to mental processes of knowledge, reasoning, memory, judgement and perception?

  • A. Cognitive
  • B. Affective
  • C. Digital
  • D. Analog

52. What sound characteristic relates to a sonic time pattern?

  • A. Tempo
  • B. Attack
  • C. Rhythm
  • D. Timbre

53. What is considered the most obvious conveyor of information?

  • A. Sound
  • B. Speech
  • C. Music
  • D. Noise

54. Attack is a sound characteristic that refers to the way a sound begins. Which of the following is NOT an attack of sound?

  • A. Hard
  • B. Soft
  • C. Crisp
  • D. Simple

55. At what loudness level do pitch (in mels) and frequency (in Hz) are numerically equal?

  • A. 0 dB
  • B. 20 dB
  • C. 60 dB
  • D. 40 dB

56. The basic voice band has how many octaves?

  • A. 10
  • B. 4
  • C. 5
  • D. 3

57. The ratio of frequencies is termed.

  • A. interval
  • B. octave
  • C. harmonics
  • D. factor

58. What is the tonal ratio of an octave?

  • A. 1 to 2
  • B. 1 to 3
  • C. 2 to 1
  • D. 3 to 1

59. If the loudness level is 100 phons, what is this in sone unit?

  • A. 100
  • B. 90
  • C. 106
  • D. 96

60. What octave bands are there in the midrange?

  • A. 1st and 2nd
  • B. 5th, 6th and 7th
  • C. 3rd and 4th
  • D. 8th and 9th

61. How much louder is 80 phons over 60 phons?

  • A. 1000 times
  • B. 4 times louder
  • C. 100 times
  • D. Twice as loud

62. What increase in sound level is commonly perceived by most people?

  • A. 6 to 10 dB
  • B. 1 to 3 dB
  • C. 3 to 6 dB
  • D. 10 to 20dB

63. What is typical loudness level of an acoustic guitar 1 foot away?

  • A. 60 dB
  • B. 100 dB
  • C. 80 dB
  • D. 40 dB

64. What do you call the perceptible sound repetition?

  • A. Reverberation
  • B. Echo
  • C. Reflection
  • D. Masking

65. What is the amount of sound reduction provided by a barrier – wall, floor, or ceiling called?

  • A. Sound Attenuation
  • B. Transmission loss
  • C. Sound absorption
  • D. Barrier loss

66. What is the frequency of a 2-cm sound wave in sea water at 25˚C?

  • A. 76 kHz
  • B. 76 Hz
  • C. 76 MHz
  • D. 76 mHz

67. A choir consisting of 36 individuals all of whom can sing with the same intensity. A soloist sings a certain passage and then is joined by the remainder of the choir members for a repeat of the passage. What is the difference in the sound intensity level in the two cases?

  • A. 3 dB
  • B. 6 dB
  • C. 36 dB
  • D. 15.6 dB

68. For the safety and comfort of factory workers, the sound-intensity level in a certain factory must remain below 85 dB. What is the maximum sound intensity allowed in this factory?

  • A. 3.2 x 10-4 W/m2
  • B. 3.2 x 10-6 W/m2
  • C. 3.2 x 10-10 W/m2
  • D. 3.2 x 10-3 W/m2

69. What sound intensity corresponds to a sound-intensity level of 50 dB?

  • A. 1 x 10-6W/m2
  • B. 1 x 10-7W/m2
  • C. 1 x 10-8W/m2
  • D.1 x 10-5W/m2

70. The sound intensity received from the nearby jet plane is 12.6 µW/m2 and that from another jet plane some distance away is 0.45 µW/m2. Find the relative loudness of the two.

  • A. 14.0 dB
  • B. 14.5 dB
  • C. 12.5 dB
  • D. 14.5 dB

71. The noise from an airplane engine 100 ft from an observer is found to have an intensity of 45dB. What will be the intensity when the plane flies overhead at an altitude of 1 mi?

  • A. 10.5 dB
  • B. 34.5 dB
  • C. 35 dB
  • D. 20.5 dB

72. What is the apparent loudness of 80 dB?

  • A. Moderate
  • B. Very loud
  • C. Loud
  • D. Deafening

73. What loudness level in which permanent damage to hearing is possible?

  • A. 120 dB
  • B. 140 dB
  • C. 130 dB
  • D. 150 dB

74. What is sound pressure level if the RMS sound pressure is 100 μbars?

  • A. 114 dB
  • B. 11.4 dB
  • C. 94 dB
  • D. 57 dB

75. What is the velocity of sound in wood (m/s)?

  • A. 330
  • B. 3600
  • C. 3300
  • D. 5800

76. What is the optimum reverberation time at 500 to 1000 Hz of an auditorium?

  • A. 0.9 to 1.1 s
  • B. 1.4 to 1.6 s
  • C. 1.5 to 1.6 s
  • D. 1.6 to 1.8 s

77. For a cinema, the optimum volume per person required is

  • A. 3.1
  • B. 2.8
  • C. 7.1
  • D. 4.2

78. Which of the following is NOT an acoustical defect to be avoided in acoustical designs?

  • A. Reverberation
  • B. Flutter echo
  • C. Distortion
  • D. Sound concentration

79. What absorber in which efficient absorption is only possible over a very narrow band approaching 1.0 (total absorption)?

  • A. Porous material
  • B. Helmholtz resonator
  • C. Panel Absorber
  • D. Membrane absorber

80. How many voice signals (4 kHz max.) would fit into a 5 MHz spectrum?

  • A. 1250
  • B. 500
  • C. 1000
  • D. 1500

81. How many FM stations would be accommodated I an ordinary TV channel?

  • A. 33
  • B. 30
  • C. 40
  • D. 25

82. What is the actual length in feet of a one-quarter wavelength of a coax with a velocity factor of 0.695 at 45 MHz?

  • A. 17.82
  • B. 19.26
  • C. 16.28
  • D. 16.97

83. Determine the terrain sensitivity loss for a 4-GHz carrier that is propagating over a very dry, mountainous area.

  • A. -1.25 dB
  • B. -3.05 dB
  • C. -2.01 dB
  • D. -5.01 dB

84. A satellite transmitter operates at 4GHz with an antenna gain of 4dBi. The receiver 40000 km away has an antenna gain of 50 dBi. If the transmitter has a power of 8 W, find (ignoring feedline losses and mismatch) the EIRP in dBW.

  • A. 50
  • B. 69
  • C. 49
  • D. 30

85. A radio signal moves from air to glass. The angle of incidence is 20°. Calculate the angle of refraction. The relative permittivity of the glass is 7.8.

  • A. 7.8°
  • B. 5.04°
  • C. 6.04°
  • D. 7.04°

86. At a certain time, the MUF for transmission at an angle of incidence of 75° is 17 MHz. What is the critical frequency?

  • A. 4.4 MHz
  • B. 3.5 MHz
  • C. 6.5 MHz
  • D. 1.5 MHz

87. A properly matched transmission line has a loss of 1.5 dB/100m. if 10 W is supplied to one end of the line, how many watts reach the load, 27 m away?

  • A. 10 W
  • B. 7.2 W
  • C. 9.9 W
  • D. 9.1 W

88. The electromagnetic radiation theory was profounded by

  • A. Sir Edward Appleton
  • B. Guglielmo Marconi
  • C. Heinrich Hertz
  • D. James C. Maxwell

89. What is caused by the transverse nature of electromagnetic waves?

  • A. Polarization
  • B. Interference
  • C. Beamwidth
  • D. Gain

90. Which propagation method is known as special case of skywave?

  • A. Space wave
  • B. Troposcatter
  • C. Ground wave
  • D. Direct wave

91. What is the orbit inclination of geostationary satellites?

  • A. 0°
  • B. 10°
  • C. 20°
  • D. 30°

92. A transmission line of unknown impedance is terminated with two different resistances, and an SWR is measured each time. With a 75 Ω termination, the SWR measures 1.5. With a 300 Ω termination, it measures 2.67. What is the impedance of the line?

  • A. 100 Ω
  • B. 212 Ω
  • C. 300 Ω
  • D. 112 Ω

93. What is the high frequency sound that cannot be heard by the human ear?

  • A. Ultrasonic
  • B. Transonic
  • C. Subsonic
  • D. Supersonic

94. What frequency is 10 octaves above 30 Hz?

  • A. 30.72 kHz
  • B. 30 kHz
  • C. 300 Hz
  • D. 307.2 kHz

95. A radio signal travels ____ yards per microseconds.

  • A. 273
  • B. 328
  • C. 618
  • D. 123.6

96. What is the actual length in feet of a one-half wavelength of a coax with a velocity factor of 0.63 at 28 MHz?

  • A. 44.28
  • B. 43.46
  • C. 11.07
  • D. 46.27

97. The range of speech power is ____.

  • A. 1 – 10 watts
  • B. 100 – 1000 milliwatts
  • C. 10 – 100 milliwatts
  • D. 10 – 1000 microwatts

98. What is the actual length in feet of a one-quarter wavelength of a coax with a velocity factor of 0.68 to 30 MHz?

  • A. 19.26
  • B. 5.6
  • C. 17.82
  • D. 16.97

99. What is actual length in feet of a one-half wavelength of a coax with a velocity factor of 0.59 at 26 MHz?

  • A. 11.16
  • B. 40.29
  • C. 42.46
  • D. 46.28

100. The agreed standard for measuring loudness is the loudness sensation produced by a 1000 Hz sine wave _____ dB above the listener’s threshold of hearing.

  • A. 80
  • B. 50
  • C. 30
  • D. 40

Complete List of Communications Engineering Exams: ECE Pre-Board

Series of Communications Engineering Exams: ECE Pre-Board

Check your work.

Answers key in Communications Engineering Exam 7: ECE Pre-Board


          Electronics Technician (S&C Technician) - Kenora - Canadian Pacific - Kenora, ON   
Valid driver’s license is required; A Class 3 license and air brake qualification would be an asset; Use digital &amp; analog multi-meters, oscilloscopes, and...
From Canadian Pacific - Tue, 20 Jun 2017 02:12:43 GMT - View all Kenora, ON jobs
          Controls Field Service Technician - National Oilwell Varco - Oklahoma City, OK   
Ability to utilize various electrical diagnostic tools including multimeters, oscilloscope, and basic hand tools....
From National Oilwell Varco - Fri, 30 Jun 2017 03:28:42 GMT - View all Oklahoma City, OK jobs
          Firmware Engineer - Molex - Buffalo, NY   
Digital Multimeter (DMM), Oscilloscope, Power Supply, Logic Analyzer, J-TAG debugger, Solder Rework. Sensorcon (a division of Molex) researches, develops, and...
From Molex - Mon, 15 May 2017 18:54:35 GMT - View all Buffalo, NY jobs
          Controls Field Service Technician - National Oilwell Varco - Oklahoma City, OK   
Ability to utilize various electrical diagnostic tools including multimeters, oscilloscope, and basic hand tools....
From National Oilwell Varco - Fri, 30 Jun 2017 03:28:42 GMT - View all Oklahoma City, OK jobs
          Controls Field Service Technician - National Oilwell Varco - Oklahoma City, OK   
Ability to utilize various electrical diagnostic tools including multimeters, oscilloscope, and basic hand tools....
From National Oilwell Varco - Fri, 30 Jun 2017 03:28:42 GMT - View all Oklahoma City, OK jobs
          Firmware Engineer - Molex - Buffalo, NY   
Digital Multimeter (DMM), Oscilloscope, Power Supply, Logic Analyzer, J-TAG debugger, Solder Rework. Sensorcon (a division of Molex) researches, develops, and...
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          System Validation Co-op - Intel - Vancouver, BC   
Performance testing of products using testing instruments such as oscilloscopes and thermal chambers. You must possess the below minimum qualifications to be...
From Intel - Fri, 09 Jun 2017 10:28:39 GMT - View all Vancouver, BC jobs
          Hackaday Links: July 2, 2017   

A few months ago, we had a Hack Chat with Chip Gracey, the guy behind Parallax, the Basic Stamp, the Propeller, and the upcoming Propeller II. Now we’ve finally got around to editing that transcript. There’s a lot of awesome stuff in here, from learning a Hardware Design Language to the actual costs of fabbing silicon.

Rigol, the manufacturers of every hackerspace’s favorite oscilloscope, announced a new chipset. The current lineup of Rigol scopes top out at around 1GHz. In a prototype scope based on this chipset, Rigol demonstrated 4GHz bandwidth and 20GS/s with one Billion point memory depth. What …read more


          Axoloti 3d shape rotation patch   

This is a basic Axoloti patch for 3d shape rotation on a x y monitor/oscilloscope. The patch uses the vertices data from shapes created in OsciStudio and then copied to tables. For the conversion you can use this spreadsheet: Oscistudio table conversion spreadsheet
Inside the patch there are already 3 different example shapes.
Download patch: Axoloti 3d shape rotation patch









          Emergence 2020, thème bien choisi mais …. ( Par Omar S.)   
Emergence 2020, thème bien choisi mais …. ( Par Omar S.)

Lorsque dans l’après midi du 11 avril 2011, le boulevard s’ouvrait enfin pour que Ouattara prenne place dans le fauteuil présidentiel, nous nous sommes tous posés la question de savoir quel était son plan pour mettre le pays sur les rails. Le chantier était gigantesque ; la Cote d’ivoire qui lui tendait la main était au niveau où Houphouët-Boigny l’avait laissée en 1993 : plantations de café et de cacao vieillissantes, infrastructures amorties et dégradées, une industrialisation morose, un système éducatif inadapté à cause du nombre pléthorique d’apprenants, comparé aux capacités d’accueil,  une mentalité fondue dans la corruption, le vol et l’enrichissement des politiciens au détriment du petit peuple travailleur…    Pourtant, Ouattara avait déjà son plan depuis le Golf Hôtel. À l’image de la transition opérée dans certains pays comme le Brésil, l’Inde, L’Afrique du Sud et les « Dragons et Tigres » d’Asie, Ouattara affirmait pouvoir extirper la Côte d’Ivoire du lot des pays du quart-monde pour la rendre émergente. Sans opposition réelle,  dans un climat de paix sociale, avec la confiance des bailleurs de fonds, et un pays à construire, rien n’empêchait Ouattara de réussir. Quel bilan de l’émergence six ans après ?

 

Nous prendrons comme appui, l’éducation, les stratégies industrielles, l’autosuffisance alimentaire, la moralisation de la vie publique, et les disparités régionales.  

 

Le premier secteur où l’émergence devrait prendre son envol, était celui de l’éducation. C’est ce que les pays d’Asie (sur lesquels l’émergence est d’ailleurs calquée) ont étudié très tôt, pour arriver à la conclusion que l’un des facteurs explicatifs des différents niveaux de vie entre pays pauvres et riches était le degré d’éducation de la population. Plus le niveau intellectuel du capital humain d’un pays est faible, moins ce pays se développera. C’est après avoir pensé cet enjeu, que Ouattara aurait dû envoyer ses experts en éducation pour maitriser le mécanisme employé depuis la fin des années 70 dans ces pays. Qu’ont-fait ces pays ? Ils se sont adonnés à de véritables réformes en adaptant aux besoins de leurs pays, les cursus scolaires, les emplois du temps des enseignants, les effectifs des classes, les mesures disciplinaires. C’est ainsi que l’accent a été mis dans tous ces pays, sur la construction d’infrastructures, leur équipement et une forte tendance vers la maitrise des sciences et techniques. Moins de vingt ans après, les résultats sont là : la Chine, l’Inde, la Thaïlande ont plus ou moins des infrastructures routières de qualité, et fabriquent leurs propres voitures. La Thaïlande est d’ailleurs devenue, le pays où  la production automobile connait la plus forte croissance au monde, et ces bonnes notes découlent de ce qui a été fait en amont dans l’éducation. Pendant ce temps qu’a fait la Cote d’ivoire pour tendre vers l’émergence ? Elle a fermé les universités pour  deux ans, puis a injecté 110 milliards pour leur réhabilitation, certains URES déjà existantes ont été brusquement baptisées universités, sans accroissement réel des capacités d’accueil et des moyens de formation, certaines cités universitaires sont toujours en ruine, et un système LMD a été superposé sur l’ancienne méthode, sans agencement adéquat avec la réalité du terrain. Au niveau du secondaire, en 4 ans (2011 à 2015) 15313 salles de classes ont été ouvertes,  2188 écoles primaires, ainsi que 170 établissements secondaires ont été construites. Hélas, le rythme de distribution de matériels didactiques, d’équipement des classes reste toujours très lent. L’on voit encore des écoles où les enfants occupent à trois les tables bancs (lorsqu’il y’en a), 70% des apprenants ignorent ce qu’est une éprouvette graduée, les acides, l’oscilloscope, et dans le fond, toutes les méthodes ont changé. Désormais, au premier cycle, les matières d’éveil et la conduite ont les mêmes coefficients que les matières scientifiques et littéraires. Conséquence, l’accent est mis sur le taux de réussite au détriment de la qualité de la formation. Nous apprenions samedi dernier que 80,98%  des postulants à l’entrée en 6ème ont été déclarés admis. Mais combien savent lire leurs noms écrits ?

 

L’éducation actuelle étant en déphasage avec les méthodes des pays déjà émergents, qu’en est-il de l’industrialisation ? Rappelons que tous ces pays cités en exemple en matière d’émergence, ont mis l’accent sur une position dominante, spécifique à chacun d’eux sur le plan industriel, et s’en sont fait exportateurs. Citons en exemple Singapour pour les disques durs (processus entamé depuis 1980, aujourd’hui, leader mondial), la Corée du Sud pour les Télévisions, Taiwan avec les consoles d’ordinateurs… alors en adaptant ces modèles au nôtre que pouvaient faire les chantres de l’émergence à la sauce ivoirienne ? Tout simplement rechercher une certification qualitative  des produits dérivés du café et cacao (premier producteur mondial), lancer un vaste programme de sensibilisation au sujet de la consommation du chocolat local et du café, opter pour une exportation d’abord vers la sous-région puis varier progressivement les débouchés. Hélas, nous sommes encore au stade de l’exportation des fèves de cacao (même pas semi-fini) et lorsque par comédie et complaisance, le siège de l’Organisation Internationale du Cacao est délocalisé à Abidjan on fait la fête, comme si ce geste boosterait le processus de transformation et d’exportation du cacao.

 

L’émergence, c’était aussi tendre vers l’autosuffisance pour les produits alimentaires de consommation de masse. Ce principal produit est connu, il s’agit du riz. Qu’est-ce qui a été fait pendant ces 6 dernières années, pour nous rendre indépendant des zones marécageuses rizicoles du Vietnam, de la Thaïlande, ou de la Chine ? On se rappelle que le 31 janvier 2013, Margarita Louis-Dreyfus du groupe du même nom, avait obtenu des autorités d’Abidjan un accord pour lancer son projet de riz paddy d’un coût de 60 milliards. Depuis lors où en sommes nous avec ce plan ? Aucune communication. Pourtant, il suffisait de regarder dans les vieux tiroirs du ministère de l’agriculture pour sortir les documents ayant servi aux projets précédents l’indépendance tel ceux de la Société d'Assistance Technique et la Motorisation Agricole en Côte d'Ivoire (SATMACI), par la suite pour parachever le processus de l’autosuffisance, fut créeee la SODERIZ en 1970. Nous parlons d’une imminente émergence dans trois ans, alors que lorsque nous sommes à table, que ce soit le contenu du verre, de l’assiette, de la soupière, la nappe et même la serviette de table, tout est importé. Alors de quelle émergence alimentaire parlons-nous ?

 Un autre facteur conduisant à l’émergence des pays sus cités est la moralisation de la vie publique, et singulièrement au sommet de l’Etat. Combien de fois n’avons-nous pas appris que tel homme politique, ou tel PDG, brésilien, coréen, ou indien  a rendu sa démission pour se mettre à la disposition de la justice de son pays, lorsqu’il est soupçonné d’être impliqué dans un scandale ? Ce genre de comportement a renforcé la confiance entre les peuples et leurs autorités, favorisant ainsi l’émergence de ces pays. Que voyons-nous ici ? Il existe des lois pour renforcer l’immunité de ceux qui doivent servir de locomotive en matière de modèle (Cf. article 157 et 158 de la constitution de 2016). Ce qui crée les conditions pour que l’homme de la rue ait une image très négative des politiciens. Favoritisme, corruption, gré à gré, dessous de table, impunité des sommités est un frein à l’émergence. Et c’est Ouattara lui-même qui l’a affirmé « l’émergence de la Cote d’Ivoire restera un vœu pieu, tant que le climat des affaires ne sera pas assaini » in JA  5 Mai 2013. L’homme de la rue a parlé de cette mauvaise gouvernance, les comédiens ont utilisé des méthodes humoristiques pour attirer votre l’attention, même les artistes chanteurs (Cf. concert Yodé et Siro). Finalement, c’est un imam qui a eu le courage de vous regarder droit dans les yeux pour vous dire que votre système souffre d’une gangrène.

 

 Veulent-ils rendre la Côte d’Ivoire émergente, ou bien le phénomène ne concerne qu’Abidjan et sa région ? La question est d’autant plus fondamentale qu’il existe un fort déséquilibre dans la répartition des investissements, dans la localisation des structures institutionnelles, et dans l’autonomie des autres régions vis-à-vis d’Abidjan. Nous avons l’impression que rien n’est entrepris pour la décentralisation, en un mot Abidjan étouffe. Et ce laxisme engendre, lourdeur administrative, embouteillages d’un côté, et évidemment délaissement, et frustration de l’autre. Pourtant, l’Etat pourrait créer des pôles de développement dans chaque région, et chacune d’elle pourrait avoir une spécialité. Ainsi à défaut s’être émergente, chaque région aurait un acquis dans le processus en cours.  

 

L’émergence ! Était-ce juste une simple idée, ou la volonté d’un homme de mettre son pays debout après que celui-ci ait pataugé dans le désordre pendant des décennies ? Nous pensons qu’il s’agissait juste d’une vision passive sans matérialisation réelle. Parce que si effectivement l’idée avait été bien ficelée, le président pouvait s’inspirer de Houphouët Boigny, qui en 1946, avait en projet, de doter la Côte d’ivoire de cadres compétents dans tous les domaines. Pour ce faire, 148 élèves parmi les plus méritants sont allés étudier en France, se perfectionner, et se mettre au service de leur pays. Les anciens se souviennent encore de  l’impact des Compagnons de l’Aventure 46 sur le système ivoirien, et ce durant plusieurs années. Après la genèse de l’idée de l’émergence, nous pensons sincèrement que c’est ce qui aurait dû être fait. Choisir parmi nos apprenants, nos experts, et nos cadres naissants les plus compétents, les envoyer en formation dans les pays déjà émergeants, pour que ce futur capital humain s’imprègne des facteurs, et conditions de l’émergence. Si l’Etat a investi dans la formation des ex-rebelles comme Wattao au Maroc, et d’autres en Afrique du Sud et en France, c’est qu’il pouvait investir dans la formation du capital humain des autres secteurs d’activité.   Malheureusement, l’on a pensé qu’il s’agissait de décrété émergence, sans sous-bassement pour que brusquement avant 2020, nous y soyons.

Omar S.

 

Opération marrée rouge le 18 juin à la CPI.

          (USA-CA-San Diego) Upgrade Engineer   
Upgrade Engineer **New** **California,San Diego** at https://cymer.referrals.selectminds.com/jobs/543/other-jobs-matching/location-only Field Service 0005551Requisition # Share this Job **_ENVISON YOUR FUTURE AT CYMER!_** Cymer, an ASML Company, is the leader in developing light sources used by chipmakers worldwide to pattern advanced semiconductor chips. We're at the forefront of technology innovation because of the extraordinary efforts and ingenuity of our employees. Cymer is the world's leading provider of lithography systems for the semiconductor industry. Through innovation, Cymer is an integral part of today’s technology landscape and is leading the light Generation. _One Company, One Goal, Limitless Innovation. It's our people that make the difference._ **SUMMARY** **Cymer** an ASML Company is the **world's leading provider of lithography systems** for the semiconductor industry. Through innovation, Cymer is an integral part of today’s technology landscape and is leading the light Generation. The **EUV Source Upgrades Engineer** is responsible for the upgrade and recovery of the EUV Source Vessel at the customer site (worldwide). The EUV Source Upgrades group will work with ASML to successfully install the upgrade hardware and recover the Source in a cost effective, proficient and timely manner. As an Upgrades Engineer you need to be “hands on” and use your technical/engineering knowledge and skills to troubleshoot and recover a large-scale, highly complex, “state-of-the art,” EUV light generation system. Furthermore, he/she could work on: + Large-scale mechanical/electrical systems, sub-systems and components + Control/software systems + Vacuum systems + High and medium powered laser beams traveling through a sophisticated optical component path (CO 2 beam path) + Water/cooling systems + Tin sphere generation and laser firing/targeting systems + EUV light: generation; optimization; measurement (metrology); and collecting systems **Duties and Responsibilities** + An Upgrades Engineer encompasses 2 competencies (will be assigned to one of them): + **CO2 Engineer:** Responsible for mechanical/optical alignment and recovery of the CO2 path (Seed Table, Drive Laser and BTS) + **Recovery and PQ Engineer:** Responsible for the recovery of the Source vessel. Recovery includes resolving all the issues that are impeding the generation of light, EUV light generation and ultimately optimization (bringing up the system). + Worldwide travel up to 60% is required, no longer than 5 weeks (continuous) at a time. Also, must be able to work in a 24 hour x 7 day environment, i.e. any shift, any day. + Takes ownership and resolves medium type of technical issues/problems during the upgrade. + Trains less experienced engineers in their area of expertise. + Takes proper actions to minimize impact on cycle time when new issues arise. Furthermore, is fervent in working with the Project Leader/Site Coordinator in determining how to reduce the cycle time for the current and subsequent upgrades. + Adheres to the escalation process to involve other groups to resolve issues in an expeditious manner. + Prevents issues from re-occurring by writing Service Orders (SOs) so that issues can be logged and resolved. + Checks tools and parts on site before the upgrade starts. + Keeps the Site Coordinators up to date on schedule, planning and roadblocks. + Uses and refines procedures before and during the upgrade. Feedbacks procedure corrections and improvements through the appropriate way of working. + Interacts with cross-functional groups (engineers and scientists, worldwide customer support personnel, manufacturing personnel, upper management, etc.). Crosses functional boundaries and builds constructive and effective relationships throughout the whole organization. + Interacts and works in a team environment with many individuals of different nations and cultures in an effective and efficient way. + Performs other duties as assigned. **QUALIFICATIONS** + Minimum of two (2) years of experience is required. + BS in Optical Engineering, Electrical Engineering, Engineering Physics, Physics, Applied Physics, or Mechanical Engineering. + Worldwide travel up to 60% is required, no longer than 5 weeks (continuous) at a time. + Must be able to work in a 24 hour x 7 day environment, i.e. any shift, any day. + Background in large-scaled hardware/mechanical type of systems. + Experience in engineering, integration, operations, test, and/or technical support of large complex systems required. + Must have a combination of, and/or significant strengths in one or more of the following: electronics; control systems and software; hardware; lasers and laser induced plasma; optical components and metrology; or vacuum systems. + Experience in a large-scale semiconductor/fab equipment company is a strong plus. + Requires the ability to read and interpret engineering specifications, maintenance manuals and other pertinent engineering documents. + Proficient in reading and analyzing complex mechanical, opto-mechanical, electrical/electronic, gas, and water schematics. + Must be able to work in a complex, fast paced, highly dynamic and flexible environment, mostly team based and collaborative. + Must be able to work in cleanrooms were cleanroom and safety clothing/equipment are required. + Must be able to work in a multi-functional and multi-cultural environment. Must understand the culture to work in a unified cohesive and collaborative manner. + Ability to execute to a detailed upgrade schedule and plan. Also, the ability to work in a very structured way of working (ASML WoW). + Ability to interpret an extensive variety of technical instructions in mathematical or diagram form and deal with several abstract and concrete variables. + Requires the ability to utilize standard test equipment such as oscilloscopes, multimeters, signal generators and power meters with no direction. + Requires the ability to use optical measurement devices such as spectrometers, spectrophotometers, imaging setups, and the etc. on a routine basis. + Excellent written and verbal communication skills. + Excellent customer service skills, with an advanced understanding of customer relationship building. + Performs data collection, statistical analysis, and report summarization. Effectively reports problems through written and/or graphical formats. + Ability to use MS Word, Excel, PowerPoint, and e-mail applications. + Ability to define problems, collects data, establishes facts, and draws valid conclusions. **PHYSICAL DEMANDS and WORK ENVIRONMENT** The physical demands described here are representative of those that must be met by an employee to successfully perform the essential functions of this job. Reasonable accommodations may be made to enable individuals with disabilities to perform the essential functions. + While performing the duties of this job, the employee routinely is required to sit; walk; talk; hear; use hands to keyboard, finger, handle, and feel; stoop, kneel, crouch, twist, reach, and stretch. + The employee is occasionally required to move around the campus. + The employee may occasionally lift and/or move up to 20 pounds. + Specific vision abilities required by this job include close vision, color vision, peripheral vision, depth perception, and ability to adjust focus. + Can work under deadlines. + Schedule may vary considerably during upgrades at the customer, to include evenings and weekends as well as long hours. + The environment generally is moderate in temperature and noise level. + Must be able to read and interpret technical data, information, and documents. + Can observe and respond to people and situations and interact with others encountered in the course of work. + Can learn and apply new information or skills. Cymer offers competitive salaries and benefits including medical, dental, vision, 401(K), and FSA's. _Cymer is committed to leveraging the diverse backgrounds, perspectives, and experiences of our workforce to create opportunities for our people and the business. EOE_
          System Validation Co-op - Intel - Vancouver, BC   
Performance testing of products using testing instruments such as oscilloscopes and thermal chambers. You must possess the below minimum qualifications to be...
From Intel - Fri, 09 Jun 2017 10:28:39 GMT - View all Vancouver, BC jobs
          Firmware Engineer - Molex - Buffalo, NY   
Digital Multimeter (DMM), Oscilloscope, Power Supply, Logic Analyzer, J-TAG debugger, Solder Rework. Sensorcon (a division of Molex) researches, develops, and...
From Molex - Mon, 15 May 2017 18:54:35 GMT - View all Buffalo, NY jobs
          Firmware Engineer - Molex - Buffalo, NY   
Digital Multimeter (DMM), Oscilloscope, Power Supply, Logic Analyzer, J-TAG debugger, Solder Rework. Sensorcon (a division of Molex) researches, develops, and...
From Molex - Mon, 15 May 2017 18:54:35 GMT - View all Buffalo, NY jobs
          Firmware Engineer - Molex - Buffalo, NY   
Digital Multimeter (DMM), Oscilloscope, Power Supply, Logic Analyzer, J-TAG debugger, Solder Rework. Sensorcon (a division of Molex) researches, develops, and...
From Molex - Mon, 15 May 2017 18:54:35 GMT - View all Buffalo, NY jobs
          Hackaday Links: July 2, 2017   

A few months ago, we had a Hack Chat with Chip Gracey, the guy behind Parallax, the Basic Stamp, the Propeller, and the upcoming Propeller II. Now we’ve finally got around to editing that transcript. There’s a lot of awesome stuff in here, from learning a Hardware Design Language to the actual costs of fabbing silicon.

Rigol, the manufacturers of every hackerspace’s favorite oscilloscope, announced a new chipset. The current lineup of Rigol scopes top out at around 1GHz. In a prototype scope based on this chipset, Rigol demonstrated 4GHz bandwidth and 20GS/s with one Billion point memory depth. What …read more


          Taiwan   

An adventure of food, cities, industry, and astonishing natural landscapes.

Flights

CX893 (SFO » HKG)

CX474 (HKG » TPE)

CX511 (TPE » HKG)

CX870 (HKG » SFO)

I'm not sure I really knew what to expect when I was on the plane to Taiwan. It's somewhere I only really knew about incidentally, like when Taipei 101 was crowned the tallest building in the world, or that lot of my electronics have, engraved in small text, the words "MADE IN TAIWAN". Still, the best way to know a place is to go there!

I had been invited by the fine people of PyCon Taiwan to give a keynote, and with my slides completed before I left San Francisco, I quickly found myself on the train from the airport, Taiwanese dollars in my pocket and with a whole afternoon to spend before the conference started the next day.

Note

You can get an RFID travel card from a machine at the airport station, and it'll work on pretty much anything.

As I navigated through the MRT system to a restaurant to get some lunch, the bustle and the flow of people immediately felt much like any other big city I've been to. Sure, the city and its architecture are a little bit less fancy than in New York, London or Tokyo, but the people are friendly and the transport network is beyond that of most American cities (despite the fact that the first line opened only two decades ago).

I found a small restaurant and decided to take in some of the local food as well as reading up on the rather tumultuous history of Taiwan; it's somewhat unique, after all.

Food

Food is, for me, one of the things that defines a city, and Taipei certainly has no shortage of it. The city's night markets are one of the things I had heard about before going there, and wandering through them is an experience in both smell, taste and touch, as you push through throngs of people all excitedly ordering from a series of menus that I, and my extremely limited knowledge of Chinese writing, was unable to understand at all.

There's plenty of other places to eat as well, though, and thanks to both the conference organisers and my own wanderings around the city I was very full by the end of my week there. Taiwanese food is in abundance, of course, but there's plenty of cuisines from mainland China, Japan, and other surrounding areas, as well as western food if you go looking for it (I even enjoyed a nice burger at a small place called Kiwi Gourmet Burgers).

My general approach when faced with night markets or the local food stands up in the mountains was to point at things that looked tasty, and this generally resulted in a delicious meal. I have to give extra marks for the popularity of sausage stalls everywhere that will sell you skewers of delicious pork sausage at a moment's notice for very little money indeed.

Note

Bubble (or boba) tea was invented in Taipei, and now there's a shop every 50 metres or so

I can't end a food section without talking about one very important thing - milk tea, and specifically bubble tea. As a British person who now lives in America, my relationship with tea has gone from mild disinterest to significant craving, and the variety and abundance of tea in Taiwan is astonishing. It's not just bubble tea either, though of course this is where it was invented; even the normal, non-milky iced tea is made and sweetened just right, to a point where I wish someone could set up a pipeline from Taiwan to my apartment in San Francisco.

Food stalls in Maokong

Sights

The first three days of my trip were spent at the conference, meeting the Python community in Taiwan and listening to talks (and attempting to live-translate the slides of some that weren't in English). On the second night, though, and for two days afterwards, I ventured out in search of sights and anything else that might be interesting.

That second night was framed around a visit to the Guang Hua electronics markets; not only are there two buildings with multiple stories of shops hawking everything from USB cables to 3D printers, there's a whole load of stalls and smaller shops around the base as well. Taiwanese brands are very well featured here, to the extent that we were left wondering how one building can support over fifty shops selling the same Asus laptops, but there's also some gems among them, like the super-narrow shop we found that sold old oscilloscopes and electronics components.

That same night, we wandered down towards the area of Taipei 101 looking for food and deliberately tacky souvenirs, and after slurping down some beef noodles wandered across one of the most bizarre festivals I've ever seen. Titled "Taiwan Color Stage Fest", it featured a series of rather bored-looking women pole-dancing on several hundred metres of garish LED stages, as bassy music thumped away in the background. The locals I ran into there and ones I talked to afterwards both had no idea what it was, but it was certainly an unexpected surprise.

Maokong Gondola with Taipei 101

After the conference was over, I had a day to go around Taipei itself before a day trip down to Hualien and the famous Taroko Gorge. I started out by heading down towards Taipei Zoo and taking the Maokong Gondola up into the mountains to the south of Taipei. The gondola climbs almost three hundred metres up and goes out into a rather rural area, the city giving way into tree-covered mountains interspersed by temples and innumerable tea rooms. I enjoyed a nice lunch from a food stall at the top of the gondola, before having a walk around and then heading back into the city again.

I spent the afternoon walking around the centre of Taipei, taking in some of the impressively different styles of architecture, before whisking myself up to the top of Taipei 101 for a bit of tourist trap sightseeing. And I really do mean tourist trap; I've been up many tall sightseeing buildings in my life, but this is the first one I've seen with an entire floor of the sightseeing section dedicated to selling jewellery. The view is fantastic, however, and the lifts are impressively quick. Another visit to a night market for a snack, and then it was back to the hotel for a 6am rise to get to Taroko.

Taroko

Taroko Gorge

I've been lucky enough to go to many places of natural spectacle over the years - Niagara Falls, the Grand Canyon, the Great Barrier Reef - and Taroko Gorge rivals them all. I've been to very few places that inspire pure awe, and the sight of the Liwu River cutting through the marble cliffs of Taroko is one of them.

Note

I cannot fit a guide to the ticket system in here, but you have to order seats on one site but pay for them on another!

When I was initially planning my trip, Taroko kept coming up in guides to Taiwan, and so I added a day to my itinerary to go down and see it. The conference organisers helped me out with when and where to book the trains - the fast train down to Hualien takes just over 2 hours, but they sell out quickly so you need to book a seat in advance - via one of the most confusing and puzzling train booking systems I've ever encountered.

Once you have a ticket, though, the train down is indeed fast and efficient, with the train speeding through mountains, along the coastline, and via some impressively long tunnels before dropping you off at Hualien station. This definitely isn't Taipei any more; it's noticeably more rural, the skyline quickly giving way to the coast in the distance, though it's still plenty busy when a train arrives.

You have a couple of choices to get yourself to Taroko Gorge from Hualien; there's a bus that goes to most of the major stops, but it's only every hour or so. The local favourite is apparently to rent a scooter and putter the half-hour north along local roads before winding your way up the gorge itself.

While I love driving mountain roads on two wheels (though preferably with more than 50cc of engine capacity), the hot, rainy weather and my time constraints led me to rent a car from the Avis branch right outside the station. International Driving Permit in hand, I was quickly in possession of a rather normal Ford Focus and motoring up the local highway towards Taroko.

Driving in Taiwan is not too different to elsewhere, except that drivers and pedestrians both have a rather impressive amount of self-confidence and will happily go where they please, only mostly staying within the bounds of the roads and signs. A decent amount of patience, though, and a willingness to work with other drivers to get around obstacles, and it's a fine drive.

The weather meant that the entrance to the gorge was shrouded in cloud, the already-impressive size of the place made even more breathtaking as I wove my way through it, cliffs seemingly disappearing up into infinity, mountains almost floating in the sky as cloud ringed their bases. Some research the day before had yielded a list of recommended trails along the gorge, and instinct led me to start at the top end of the gorge and work down, trying to avoid the numerous coach tours.

Marble cliffs lead to the river below

As you drive along the gorge, the one-way, two-lane system becomes one lane in each direction before giving way into single-track roads with passing places as you climb further into the mountains. Taroko National Park is more than just the gorge, and I drove 30 kilometres from the entrance up into the base of the mountains, the road hugging the cliffs next to a very steep drop but an equally impressive view, letting you see for miles over the mountain range, the clouds covering the valleys below.

Mountains ringed by cloud

I stopped here for lunch, enjoying my sandwiches up among the clouds, before starting back down on my series of short hikes. Taroko has quite a few exciting trails, though the rainy season was ending so many were closed for repair due to mudslides or other problems. Still, even though I didn't manage to make it to the waterfall curtain cave, the hot springs, or the impressively long suspension bridge, it was made up for by the nature and the landscape itself. There's nothing quite like standing on the edge of the gorge as the walls tower above you and the river thunders below, listening to bird calls and watching butterflies dance in the air around you. And I did at least find one, smaller, suspension bridge I could go on.

I'd love to come back to Taroko when it's a better season, and not only are more of the paths and trails open but the weather is a bit more amenable to hiking. I'm a cold-weather person (after all, I willingly visited Alaska in the winter), and so an average temperature of over 30°C and relative humidity of over 80% meant that anything more than a couple of kilometres round-trip was too much for me.

After a day in the gorge, I drove back down to sit on the beaches of Hualien and take in the dramatic coastline while waiting for my train home. As I watched the clouds drift out of the mountains and towards the Pacific, a local jogger stopped and, with his limited English and my even more limited Mandarin, my impression of the Taiwanese as friendly and welcoming people was secured as we spent a few minutes hand-waving and trying to chat about travelling solo and visiting other countries.

In Conclusion

Note

Taiwan's status as a nation-state is disputed, but it operates as a de-facto country; separate border, separate government

I wasn't sure quite what to expect of Taiwan, and I found a country* that is exciting, beautiful, full of delicious food and welcoming people. It is still growing and developing, for sure, but already has so much to offer.

I got only a brief, week-long experience of the place, and I didn't even go to the south or west of the country, but from what I've seen I would happily return - though maybe at a time of year when it's a little bit less hot!


          Firmware Engineer - Molex - Buffalo, NY   
Digital Multimeter (DMM), Oscilloscope, Power Supply, Logic Analyzer, J-TAG debugger, Solder Rework. Sensorcon (a division of Molex) researches, develops, and...
From Molex - Mon, 15 May 2017 18:54:35 GMT - View all Buffalo, NY jobs
          (USA-NH-Hudson) Senior Electrical Engineer   
Located in Hudson, NH. This individual will work as a Senior Electrical Hardware Engineer in the Precision Guidance and Sensing Solutions engineering team supporting development and production of man-portable thermal imaging and missile seeker products. As a Senior Electrical Engineer you will design and oversee the manufacture of electrical circuits and circuit cards while interfacing with other team members representing a wide range of disciplines, including integrated circuit design, test engineering, software engineering, mechanical design, and system design. You will work closely with members of the Electrical Engineering team, including being a mentor, to use techniques and approaches to achieve design, manufacturing and test objectives. This individual will also work with program leadership and have a proven track record in concept generation and trade studies, and meeting hardware unit cost and program budget and schedule objectives. The successful candidate will demonstrate a clear dedication to taking ownership of his or her work, a drive to not leave tasks incomplete or not understood, and be absolutely committed to making the team, product and program successful. **Duties and Responsibilities:** + Design electronic circuits, select components, and capture schematics. + Support Principal Electrical Engineers in defining electronic architectures including power supplies, analog video chains, digital processing circuits for infrared and visible camera systems. + Troubleshoot and debug electronic circuits. + Oversee layout of Printed Circuit Boards. + Work with PCB and CCA manufacturers to procure CCAs. + Execute Design Verification Testing of CCAs. + Facilitate design reviews and customer/supplier interactions as required. + Design, develop, analyze, document and support testing of products, systems, and subsystems. + Support ongoing product issues by providing technical investigation and analysis to correct design and production yield issues. + Communicate clearly (written and oral) with other company personnel and customers as required. + Provide technical knowledge and assistance to other engineers and support personnel. + Able to work on multiple assignments and with multiple teams simultaneously. + Excels in problem solving and troubleshooting. + Other duties as assigned. **Minimum Education And Experience** Bachelor's Degree and 5-10 years work experience or equivalent experience **Required Skills And Education** + Experience with laboratory work protocols and standard test and measurement equipment (i.e. power supplies, oscilloscopes, instrumentation). + Experience with or exposure to schematic tools (Cadence, Mentor, Altium, other). + Basic software programming experience (C, C , Java, Visual Studio, other). + Experience with Microsoft Office tools such as Excel, PowerPoint, Word, and Visio. **About BAE Systems Intelligence & Security** BAE Systems is a premier global defense and security company with approximately 90,000 employees delivering a full range of products and services for air, land and naval forces, as well as advanced electronics, security, information technology solutions and customer support and services.The Electronic Systems (ES) sector spans the commercial and defense electronics markets with a broad portfolio of mission-critical electronic systems, including flight and engine controls; electronic warfare and night vision systems; surveillance and reconnaissance sensors; secure networked communications equipment; geospatial imagery intelligence products and systems; mission management; and power-and energy-management systems. Headquartered in Nashua, New Hampshire, ES employs approximately 13,000 people globally, with engineering and manufacturing functions primarily in the United States, United Kingdom, and Israel. Equal Opportunity Employer/Females/Minorities/Veterans/Disabled/Sexual Orientation/Gender Identity/Gender Expression **Senior Electrical Engineer** **Hudson, New Hampshire** **24953BR-1740**
          Communications Engineering Mastery Test 8: ECE Pre-Board   

Communications Engineering Exam 8

This is 100 items set of Practice Examination 8 in Communications Engineering (Electronics Systems and Technology) composed of previous Board Exams Questions. Read each questions and choices carefully! Choose the best answer. In the actual board, you have to answer 100 items in Communications Engineering within 5 hours. You have to get at least 70% to pass the subject. Communications Engineering is 30% of the total 100% Board Rating along with Mathematics (20%), General Engineering and Applied Sciences (20%) and Electronics Engineering (30%). Familiarize each and every questions to increase the chance of passing the ECE Board Examination.

Start the Test Yourself Exam 8

Choose the letter of the best answer in each questions.

1. What is the refractive index of an ionospheric layer with 100 x 105 free electrons per m3?

Assume frequency to be at 20 MHz.

  • A. 0.99
  • B. 0.15
  • C. 0.78
  • D. 0.85

2. “Each point on a spherical wavefront may be considered a source of secondary spherical wavefronts”. This is known as the

  • A. Snell’s law
  • B. D’Alembert’s principle
  • C. Appleton’s theory
  • D. Huygen’s principle

3. What is meant by the term deviation ratio?

  • A. The ratio of the audio modulating frequency to the center carrier frequency.
  • B. The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency.
  • C. The ratio of the carrier center frequency to the audio modulating frequency.
  • D. The ratio of the highest audio modulating frequency to the average audio modulating frequency.

4. What is the major cause of selective fading?

  • A. Small changes in the beam heading at the receiving station.
  • B. Large changes in the height of the ionosphere, as experience at the receiving station.
  • C. Time differences between the receiving and transmitting stations.
  • D. Phase differences between radio wave components of the same transmission, as experienced at the receiving station.

5. What phenomenon causes the radio-path horizon distance to exceed the geometric horizon?

  • A. E-layer skip.
  • B. D-layer skip.
  • C. Auroral skip.
  • D. Radio waves may be bent.

6. What propagation condition is usually indicated when a VHF signal is received from a station over 500 miles away?

  • A. D-layer absorption
  • B. Faraday rotation
  • C. Tropospheric ducting
  • D. Moonbounce

7. What is meant by the term modulation index?

  • A. The processor index.
  • B. The ratio between the deviation of a frequency modulated signal and the modulating frequency.
  • C. The FM signal-to-noise ratio.
  • D. The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency.

8. The bending of radio waves passing over the top of a mountain range that disperses a weak portion of the signal behind the mountain is

  • A. eddy-current phase effect
  • B. knife-edge diffraction
  • C. shadowing
  • D. mirror refraction effect

9. What is the wavelength of a signal at 500 MHz?

  • A. 0.062 cm
  • B. 6 meters
  • C. 60 cm
  • D. 60 meters

10. What is included in the total resistance of an antenna system?

  • A. Radiation resistance plus space impedance
  • B. Radiation resistance plus transmission resistance
  • C. Transmission line resistance plus radiation resistance
  • D. Radiation resistance plus ohmic resistance

11. What are electromagnetic waves?

  • A. Alternating currents in the core of an electromagnet
  • B. A wave consisting of two electric fields at right angles to each other
  • C. A wave consisting of an electric field and a magnetic field at right angles to each other
  • D. A wave consisting of two magnetic fields at right angles to each other

12. The band of frequencies least susceptible to atmospheric noise and interference is:

  • A. 30 – 300 kHz
  • B. 300 – 3000 kHz
  • C. 3 – 30 MHz
  • D. 300 – 3000 MHz

13. What is the relationship in degrees of the electrostatic and electromagnetic fields of an antenna?

  • A. 0 degree
  • B. 45 degrees
  • C. 90 degrees
  • D. 180 degrees

14. For a space wave transmission, the radio horizon distance of a transmitting antenna with a height of 100 meters is approximately:

  • A. 10 km
  • B. 40 km
  • C. 100 km
  • D. 400 km

15. What is meant by referring to electromagnetic waves as horizontally polarized?

  • A. The electric field is parallel to the earth.
  • B. The magnetic field is parallel to the earth.
  • C. Both the electric and magnetic fields are horizontal
  • D. Both the electric and magnetic fields are vertical

16. What is meant by referring to electromagnetic waves as having circular polarization?

  • A. The electric field is bent into a circular shape.
  • B. The electric field rotates
  • C. The electromagnetic wave continues to circle the earth
  • D. The electromagnetic wave has been generated by a quad antenna

17. If a transmitting antenna is 100 meters high and a separate receiving antenna is 64 meters high, what is the maximum space wave communication distance possible between them?

  • A. 18 km
  • B. 72 km
  • C. 164 km
  • D. 656 km

18. A receiver is located 64 km from a space wave transmitting antenna that is 100 meters high. Find the required height of the receiving antenna.

  • A. 36 meters high
  • B. 64 meters high
  • C. 100 meters high
  • D. 182.25 meters high

19. Which of the following is not one of the natural ways a radio wave may travel from transmitter to receiver?

  • A. Ground wave
  • B. Microwave
  • C. Sky wave
  • D. Space wave

20. Which of the following terrain types permits a ground wave to travel the farthest?

  • A. Salt water
  • B. Fresh water
  • C. Sandy
  • D. Rocky

21. What is the input terminal impedance at the center if a folded dipole antenna?

  • A. 300 ohms
  • B. 72 ohms
  • C. 50 ohms
  • D. 450 ohms

22. What is the term used to describe a spread spectrum communications system where the center frequency if a conventional carrier is altered many time per second in accordance with a pseudo-random list of channels?

  • A. Frequency hopping
  • B. Direct sequence
  • C. Time-domain frequency modulation
  • D. Frequency compandored spread spectrum

23. What is the velocity factor for non-foam dielectric 50 or 75 ohm flexible coaxial cable such as RG 8, 11, 58 and 59?

  • A. 2.70
  • B. 0.66
  • C. 0.30
  • D. 0.10

24. If a transmission line has a power loss of 6 dB per 100 feet, what is the power at the feed point to the antenna at the end of a 200 foot transmission line fed by a 100 watt transmitter?

  • A. 70 watts
  • B. 50 watts
  • C. 25 watts
  • D. 6 watts

25. What determines the velocity factor in a transmission line?

  • A. The termination impedance
  • B. The line length
  • C. Dielectrics in the line
  • D. The center conductor resistivity

26. What term is used to describe a spread spectrum communications system in which a very fast binary bit stream is used to shift the phase of an RF carrier?

  • A. Frequency hopping
  • B. Direct sequence
  • C. Binary phase-shift keying
  • D. Phase compandored spread spectrum

27. Which of the following frequency bands is best suited for ground wave propagation?

  • A. 30 to 300 kHz
  • B. 300 kHz to 3 MHz
  • C. 3 MHz to 30 MHz
  • D. 30 MHz to 300 MHz

28. Which of the following frequency bands is best suited for sky wave propagation?

  • A. 30 to 300 kHz
  • B. 3 MHz to 30 MHz
  • C. 30 MHz to 300 MHz
  • D. 3 GHz to 30 GHz

29. What is the seventh harmonic of a 100 MHz quarter wavelength antenna?

  • A. 14.28 MHz
  • B. 107 MHz
  • C. 149 MHz
  • D. 700 MHz

30. Which if the following layers of the ionosphere has no effect on sky wave propagation during the hours of darkness?

  • A. D
  • B. E
  • C. F1
  • D. F2

31. Skip distance can be maximized by using the ____ radiation angle possible and the ____ frequency that will be refracted at that angle.

  • A. lowest, lowest
  • B. lowest, highest
  • C. highest, lowest
  • D. highest, highest

32. What is the meaning of the term “velocity factor” of a transmission line?

  • A. The ratio of the characteristic impedance of the line to the terminating impedance
  • B. The index of shielding for coaxial cable.
  • C. The velocity of the wave on the transmission line multiplied by the velocity of light in a vacuum.
  • D. The velocity of the wave on the transmission line divided by the velocity of light in a vacuum.

33. What is the term for the ratio of actual velocity at which a signal travels through a line to the speed of light in a vacuum?

  • A. Velocity factor
  • B. Characteristic impedance
  • C. Surge impedance
  • D. Standing wave ratio

34. Why is the physical length of a coaxial cable transmission line shorter than its electrical length?

  • A. Skin effect is less pronounced in the coaxial cable
  • B. RF energy moves slower along the coaxial cable
  • C. The surge impedance is higher in the parallel feed line
  • D. The characteristic impedance is higher in the parallel feed line

35. What would be the physical length of a typical coaxial transmission line that is electrically one-quarter wavelength long at 14.1 MHz?

  • A. 20 meters
  • B. 3.51 meters
  • C. 2.33 meters
  • D. 0.25 meter

36. To obtain the most reliable sky wave propagation the ____ should be used.

  • A. Lowest useable frequency (LUF).
  • B. Maximum useable frequency (MUF).
  • C. Optimum useable frequency (OUF).
  • D. Critical frequency

37. What is the deviation ratio for an FM-phone signal having a maximum frequency swing of plus or minus 5 kHz and accepting a maximum modulation rate of 3kHz?

  • A. 60
  • B. 0.16
  • C. 0.6
  • D. 1.66

38. Tropospheric scatter is a method of sky wave propagation for which of the following frequency bands?

  • A. 300 kHz to 3 MHz
  • B. 3 MHz to 30 MHz
  • C. 30 MHz to 300 MHz
  • D. 300 MHz to 3 GHz

39. What is the frequency range of an aircraft’s radio altimeter?

  • A. 962 MHz to 1213 MHz
  • B. 329.15 MHz to 335.00 MHz
  • C. 4250 MHz to 4350 MHz
  • D. 108.00 MHz to 117.95 MHz

40. What type of transmission is radiated from an aircraft’s radio altimeter antenna?

  • A. An amplitude modulated continuous wave
  • B. A pulse position modulated UHF signal
  • C. A differential phase shift keyed UHF signal
  • D. A frequency modulated continuous wave

41. The polarization of a radio wave:

  • A. Is perpendicular to the electrostatic field of the antenna
  • B. Is the same direction as the electrostatic field of the antenna.
  • C. Is the same direction as the magnetic field of the antenna.
  • D. Is perpendicular to both the electrostatic and magnetic fields of the antenna.

42. A coaxial cable has 7dB of reflected power when the input is 5 watts. What is the output of the transmission line?

  • A. 5 watts
  • B. 2.5 watts
  • C. 1.25 watts
  • D. 1 watt

43. When is it useful to refer to an isotropic radiator?

  • A. When comparing the gains of directional antennas
  • B. When testing a transmission line for standing wave ratio
  • C. When (in the northern hemisphere) directing the transmission in a southerly direction
  • D. When using a dummy load to tune a transmitter

44. Most AM broadcasts employ ___ polarization while most FM broadcasts employ ___ polarization of the radio wave.

  • A. vertical, vertical
  • B. vertical, horizontal
  • C. horizontal, vertical
  • D. horizontal, horizontal

45. How does the gain of a parabolic dish type antenna change when the operating frequency is doubled?

  • A. Gain does not change
  • B. Gain is multiplied by 0.707
  • C. Gain increases 6 dB
  • D. Gain increases 3 dB

46. What is the frequency range of an aircraft’s Very High Frequency (VHF) communications?

  • A. 118.000 MHz to 136.975 MHz (worldwide up to 151.975 MHz)
  • B. 108.000 MHz to 117.95 MHz
  • C. 329.15 MHz to 335.00 MHz
  • D. 2.0000 MHz to 29.999 MHz

47. What is a selective fading effect?

  • A. A fading effect caused by small changes in beam heading at the receiving station.
  • B. A fading effect caused by phase differences between radio wave components of the same transmission, as experienced at the receiving station.
  • C. A fading effect caused by large changes in the height of the ionosphere, as experienced at the receiving station
  • D. A fading effect caused by time differences between the receiving and transmitting stations.

48. If the velocity of propagation in a certain medium is 200x106 m/s, what is its refractive index?

  • A. 1.3
  • B. 1.5
  • C. 1.27
  • D. 0.67

49. What is the resultant field strength at the receiving antenna in space wave propagation under case 2?

  • A. 0
  • B. ξd
  • C. 2ξd
  • D. 3ξd

50. The decimetric wave is using what method of propagation?

  • A. Ground wave
  • B. Space wave
  • C. Sky wave
  • D. Tropospheric wave

51. What is the typical frequency used for communicating to submerged submarines?

  • A. 100 Hz
  • B. 500 Hz
  • C. 4 kHz
  • D. 200 Hz

52. Which frequency bands can be refracted during the day by the D layer?

  • A. VLF
  • B. MF
  • C. LF
  • D. Both VLF and LF

53. What height of an ionized layer is determined from the time interval between the transmitted signal and the ionospheric echo at vertical incidence?

  • A. Virtual height
  • B. Apparent height
  • C. Actual height
  • D. Effective height

54. During the night when the F2 layer combines with F1 layer it falls to what approximate height?

  • A. 250 km
  • B. 350 km
  • C. 300 km
  • D. 400 km

55. Which of the following is considered the most frequently used transmission line?

  • A. Two-wire open line
  • B. Twin lead
  • C. Rigid coaxial line
  • D. Flexible coaxial line

56. The antenna effective height is ____ to ____ of the actual height.

  • A. ½ to 2/3
  • B. ½ to ¾
  • C. ¼ to 2/3
  • D. ¼ to ¾

57. What is the propagation velocity of a signal in a transmission line whose inductance and capacitance are 5μH/m and 20μF/m respectively?

  • A. 100 x 103 m/s
  • B. 100 m/s
  • C. 10 x 103 m/s
  • D. 100 x 106 m/s

58. What is the phase coefficient in radians per unit length of a transmission line at the frequency of 10 MHz if the velocity of propagation is 2.5 x 108 m/s?

  • A. 0.25
  • B. 2.5
  • C. 0.35
  • D. 3.5

59. Determine the conductance of a two-wire open line with the following parameters: D = 4 in., d = 0.1 in. and ρ = 2.6x108 Ω-m.

  • A. 2.76 x 10-9 S/m
  • B. 2.76 x 10-6 S/m
  • C. 2.76 x 10-12 S/m
  • D. 2.76 x 10-3 S/m

60. What is the input impedance of a transmission line if its characteristic impedance is 300 Ω and the load is 600 Ω? Assume a quarter wavelength section only.

  • A. 150 kΩ
  • B. 150 mΩ
  • C. 150 Ω
  • D. 2 Ω

61. Determine the standing wave ratio of a 300-Ω line whose load is 400+j150 Ω.

  • A. 3.55
  • B. 1.67
  • C. 5.53
  • D. 3.35

62. What is the optimum volume per person of rooms for speech?

  • A. 2.8
  • B. 3.1
  • C. 4.2
  • D. 5.1

63. What happens to the beamwidth of an antenna as the gain is increased?

  • A. The beamwidth increases geometrically as the gain is increased.
  • B. The beamwidth increases arithmetically as the gain is increased.
  • C. The beamwidth is essentially unaffected by the gain of the antenna.
  • D. The beamwidth decreases as the gain is increased.

64. A superhet receiver has an IF of 455 kHz and is experiencing image-channel interference on a frequency of 1570 kHz. The receiver is tuned to

  • A. 1115 kHz
  • B. 660 kHz
  • C. 2025 kHz
  • D. 910 kHz

65. What is the end impedance of a half-wave dipole?

  • A. 73 Ω
  • B. 72 Ω
  • C. 250 Ω
  • D. 2500 Ω

66. What volume of the chamber is required to measure absorption coefficient at 100 Hz?

  • A. 125 m3
  • B. 50 m3
  • C. 150 m3
  • D. 352 m3

67. What is the optimum reverberation time at 500 Hz for a cinema?

  • A. 0.8 – 1.2 sec.
  • B. 0.9 – 1.3 sec.
  • C. 0.6 – 0.8 sec.
  • D. 0.45 – 0.55 sec.

68. An FM receiver whose intermediate frequency is 10.7 MHz, is experiencing image channel interference from a station transmitting on 121.1 MHz. If the local oscillator is tracking above, the receiver is tuned to

  • A. 131.8 MHz
  • B. 110.4 MHz
  • C. 142.5 MHz
  • D. 99.7 MHz

69. A 1 Mhz carrier is amplitude modulated by a pure 200-Hz audio test tone. Which of the following combinations of frequencies represent the total content of the AM signal?

  • A. 1 MHz and 200 Hz
  • B. 1 MHz and 1000.2 kHz
  • C. 999.8 kHz, 1000 kHz, and 1000.2 kHz
  • D. 999.8 kHz and 1000.2 kHz

70. What establishes the receiver bandwidth?

  • A. RF amplifier
  • B. Mixer
  • C. Local oscillator
  • D. IF amplifier

71. What noise type is observable between 8 MHz to somewhat above 1.43 GHz or up to 1.5 GHz?

  • A. Solar noise
  • B. Space noise
  • C. Galactic noise
  • D. Cosmic noise

72. Flicker noise is a poorly understood form of noise which may be completely ignored about above ____.

  • A.100 Hz
  • B. 200 Hz
  • C. 400 Hz
  • D. 500 Hz

73. What is the typical gain of a rhombic antenna?

  • A. Between 15 to 60
  • B. Between 20 to 90
  • C. Between 50 to 75
  • D. Between 10 to 25

74. What illumination factor is normally considered in computing parabolic antenna gain in microwave communications?

  • A. 0.54
  • B. 0.65
  • C. 0.75
  • D. 0.85

75. How many voice band channels are there in a superjumbo group?

  • A. 600
  • B. 900
  • C. 10,800
  • D. 3,600

76. In acoustics, what is the reference pressure in lb/ft2 unit?

  • A. 2x10-5
  • B. 0.0002
  • C. 2.089
  • D. 2.980

77. Which of the following characterizes a properly terminated transmission line?

  • A. The line loss is minimum.
  • B. The standing wave ratio is minimum.
  • C. The input impedance is twice the load impedance.
  • D. The standing wave ratio is one.

78. What is the meaning of forward power?

  • A. The power traveling from the transmitter to the antenna.
  • B. The power radiated from the top of an antenna system.
  • C. The power produced during the positive half of an RF cycle.
  • D. The power used to drive a linear amplifier.

79. What organization has published safety guidelines for the maximum limits of RF energy near the human body?

  • A. The American National Standards Institute (ANSI).
  • B. The Environmental Protection Agency (EPA).
  • C. The Federal Communications Commission (FCC).
  • D. The Institute Of Electrical and Electronics Engineers (IEEE).

80. When no signal is being received, the loudspeaker is not entirely silent as a result of the presence of

  • A. parasitic oscillations in some of the receiver stages.
  • B. negative feedback in each stage.
  • C. spurious frequencies as a result of improper neutralization.
  • D. internal receiver noise.

81. When measuring a transmitter’s frequency against a suitable standard, the frequency to be measured is taken from the

  • A. oscillator stage
  • B. intermediate amplifier
  • C. buffer stage
  • D. final RF stage

82. When the is the ionosphere most ionized?

  • A. Dusk
  • B. Midnight
  • C. Dawn
  • D. Midday

83. Cellular radios use FM with a maximum deviation of

  • A. ± 30 KHz
  • B. ± 75 KHz
  • C. ± 25 KHz
  • D. ± 12 KHz

84. What device measures the angle between two radio frequencies and also the direction of propagation of a wave?

  • A. Densimeter
  • B. Absorption wavemeter
  • C. Goniometer
  • D. Ergometer

85. An automated ship-to-shore distress alerting system using satellites and advanced terrestrial communications systems.

  • A. GPS
  • B. Iridium system
  • C. INMARSAT
  • D. GMDSS

86. What antenna can be used to minimize the effect of Faraday rotation of polarization?

  • A. Dipole
  • B. Parabolic
  • C. Helical
  • D. Rhombic

87. The presence of standing waves on a transmission line is the result of

  • A. a high level of attenuation on the line.
  • B. terminating the line by a resistive load equal in value to the surge impedance
  • C. reducing the input power to below its critical level.
  • D. an impedance mismatch between the load and the line.

88. What device measures rf power by measuring the heat the rf power generates?

  • A. Calorimeter
  • B. Goniometer
  • C. Spectrum meter
  • D. Oscilloscope

89. What is considered the most efficient mode in terms of energy transfer in waveguides?

  • A. Dominant mode
  • B. Normal mode
  • C. Conventional mode
  • D. Vertical mode

90. In acoustics, _____ is the apparent change in frequency or pitch when a sound source moves either toward or away from a listener.

  • A. flanking
  • B. reverberation
  • C. Doppler effect
  • D. echo

91. Which of the following wavelengths where absorption of electromagnetic waves becomes peak due to vibrational resonances in the water vapor molecule?

  • A. 1.35 cm and 1.7 mm
  • B. 1.5 mm and 5mm
  • C. 1.35 dm and 1.7cm
  • D. 1.5 cm and 5 mm

92. Oxygen molecule absorption peaks to electromagnetic wave are at what wavelengths?

  • A. 1.35 mm and 1.7 μm
  • B. 1.35 cm and 1.7 mm
  • C. 5 cm and 2.5 cm
  • D. 5 mm and 2.5 mm

93. The approximate single-hop nighttime range of F2 layer is ____.

  • A. 3000 km
  • B. 3840 km
  • C. 4130 km
  • D. 2350 km

94. What ionospheric layer has a daytime approximate critical frequency of 8 MHz?

  • A. F2 layer
  • B. F1 layer
  • C. E layer
  • D. D layer

95. In cellular system, _____ defines the geographic distance that is required between cells using identical frequencies in order to avoid interference between the radio transmissions at these cells.

  • A. frequency-reuse ratio
  • B. distance-to-reuse ratio (D/R)
  • C. reuse format plan ratio
  • D. reuse factor

96. What do you call the ability of a mobile phone to change from one channel (frequency) to another?

  • A. Frequency agility
  • B. Frequency handoff
  • C. Frequency handover
  • D. Frequency switch

97. What mathematical plane figure is ideal in cellular system design and engineering it graphically and functionally depicts overlapping radio coverage between and among adjacent cell base stations?

  • A. Hexagon
  • B. Octagon
  • C. Pentagon
  • D. Nonagon

98. In cellular system, the average lead time to install a new base station is approximately ____ months to a year.

  • A. 4
  • B. 5
  • C. 6
  • D. 10

99. What is considered the threshold of audibility at 3000 Hz?

  • A. 10-12 W/m2
  • B. 10-16 W/m2
  • C. 10-12 W/cm2
  • D. 10-15 W/cm2

100. At one atmospheric pressure, what is the approximate speed of sound in steel?

  • A. 5150 m/s
  • B. 5150 ft/s
  • C. 4990 m/s
  • D. 4990 ft/s

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Answers key in Communications Engineering Exam 8: ECE Pre-Board


          Controls Field Service Technician - National Oilwell Varco - Oklahoma City, OK   
Ability to utilize various electrical diagnostic tools including multimeters, oscilloscope, and basic hand tools....
From National Oilwell Varco - Fri, 30 Jun 2017 03:28:42 GMT - View all Oklahoma City, OK jobs
          Multi-Instrument Standard 3.7   
Sound card oscilloscope, spectrum analyzer, signal generator, multimeter,counter