Communications Engineering Coaching Materials: Section 1 Module 2

This is the Section 1 Module 2 of the compiled Communications Coaching Materials taken from different sources including but not limited to Communications books, past Board Exams Questions, Journals and the Internet.

Communications Coaching Materials: Section 1 Module 2

This is the Section 1 Module 2 of the compiled Communications Coaching Materials taken from various sources including but not limited to past Board Examination Questions in Electronic System and Technologies (EST), Communications Books, Journals and other Communications References. This particular Coaching Notes in Communications Engineering has random Questions and Answers in random topics. Make sure to familiarize each questions to increase the chance of passing the ECE Board Exam.

Communications Engineering Coaching: Section 1 Module 2

1. Extended superframe – 576 channels

2. Delta Modulation – slope overload is common problem

3. T1 – most common carrier line for telephones

4. 100 dB - RF and IF gain in receiver

5. 0.9 – velocity factor for open wire

6. 0.8 – velocity factor for twin lead

7. Critical frequency of F2 – 8 MHz

8. Ephemeris – location of a celestial body in space

9. troposcatter – 350 MHz to 10 GHz

10. End impedance of HW dipole – 2500Ω

11. single hop night time range of F2 – 4130 km

12. 3300 m/s – speed of sound in wood

13. GSM/TDMA – cannot execute soft handoff because cell sites use different sets of frequencies to communicate with each other

14. 20 phons – typical loudness level of ticking watch

15. M88 – 88 mH coil; every 9000 feet

16. Hybrid Transformer – 2 wire to 4 wire converter

17. click – square wave; rounding off something

18. SDMA – Spatial Div. Multi Access; use same frequency in multiple focused beams aim at different areas

19. IS 95 – became CDMA 2000

20. International pitch A – 435 Hz

21. Hash – 128 bits sequence in digital signature

22. Envelope Delay Distortion – caused by frequency dependent attenuation chars of transmission lines

23. POP3 – Post Office Protocol version 3

24. Why use geosynchronous satellites? To simplify tracking requirements

25. BISYNC – not a bit oriented protocol

26. flag filed for SDLC/HDC – 7Eh

27. Bit stuffing – to prevent accidental flag fields?

28. Blank and Burst – interrupt voice feed to send control signals (cellular telephony)

29. fiber optics are preferred to satellites for long distance telephone transmission because of less delay

30. real time of info – found in circuit switching

31. mechanical splicing

32. fusion splicing – the ends are melted together

33. 2 mV – TV video signal level

34. for CATV : (noise free picture)

a. 1 mV for 75Ω

b. 2 mV for 300Ω

35. Synchronous demodulation – process of getting the info from the chroma signal

36. CW Doppler Radar – used by police

37. CTCS – Continuous Tone Control Squelch; low frequency tones only

38. EO 196 – control of PHILCOM SAT to NTC

39. P 5000 – fine for no permit (MPDP)

40. P 5000 – per unit fine of unauthorized cellphone service

41. P 100 K – paid up capital

42. P 1200 – permit for MPD

43. P 300- license for CATV head end

44. Differential Peak Detector – has a peak detector

45. Sun Detector – orientation of sunlight

46. Blooming – trapped gas pockets in fiber cables

47. Service numbers – 3 digit number with specialized service

48. smart card – card with embedded IC

49. armature – part of dc radio gen which is grounded to reduce radio noise

50. MPEG4 - current video compression standard

51. 6 to 10 dB – noticeable change in loudness level

52. noise figure: (with equalizer)

a. 330 MHz – 9.5 dB

b. 54 MHz – 7.5 dB

53. 12 dB – visual signal level for channels that have other than 6 MHz nominal separation

54. 3 dB – visual signal level for channels that have 6MHz nominal separation

55. 13 to 17 dB – sound carrier lower than visual carrier

56. Cross Luminance – diagonal patterns

57. S unit – 6 dB

58. MPDP – apply at NTC regional office of area to service

59. 24.3 kBaud/sec – modulation rate for D-AMPS

60. 150 µV – receiver preamp input (CATV)

61. SSB – 200 Hz shift results in material degradation

62. +- 25V – max voltage to apply (data)

63. GMDSS – Global Maritime Distress and Safety System

64. AMPS – 10 kbps

65. Positive Carrier Shift – insufficient grid mod at grid modulation circuit

66. Negative Carrier Shift – insufficient grid mod at high power modulation

67. 100 milliroentgents/week exposure

68. 0.5 milliroentgents per hour from 5 cm

69. camera pickup tube – yellow green is most sensitive

70. wan topologies:

a. leased line

b. circuit switching

c. packet switching

71. <5% - interference to visual signal level

72. Measuring rad exposure – device should have area max 10cm2 max linear dimension is 5cm

73. 3 channels – separation between geographically adjacent stations to minimize interference

74. downtilt – limit range

75. GPS – uses CDMA for multiple access tech

76. 1800 Hz – reference frequency for envelope delay distortion measurement

77. Two tone test – SSB method in testing AM transmitter

78. Pump laser – to higher energy level

79. MPEG2 – Discrete Cosine Transform

80. IMTS – Improved Mobile Tel System; Bell Labs, 1965 or 68

81. PON – not needing to install expensive equipment at every terminal

82. Ethernet – uses 3 level Manchester code

83. CT 2 – portable payphone booth

84. SSB - assigned frequency is 1.4 kHz above carrier frequency

85. Linear amplifier – frequency instability for J3E because there’s no carrier reference

86. Horn and slot – direct connection to waveguides

Complete List of Communications Engineering Coaching Materials


Labels:

Post a Comment

Contact Form

Name

Email *

Message *

Powered by Blogger.
Javascript DisablePlease Enable Javascript To See All Widget