General Licensing Class G4

1. General Licensing Class�G4�

2. General Class Element 3 Course Presentation ELEMENT 3 SUB-ELEMENTS G1 � Commission�s Rules G2 � Operating Procedures G3 � Radio Wave Propagation G4 � Amateur Radio Practices G5 � Electrical Principles G6 � Circuit Components G7 � Practical Circuits G8 � Signals and Emissions G9 � Antennas G0 � Electrical and RF Safety

3. G4 � Amateur Radio Practices G4A Two tone test An oscilloscope may be used to measure the output of a single-sideband transmitter when performing a two-tone test of amplitude linearity.

4. G4 �Amateur Radio Practices G4A Two tone test (cont) Transmitter linearity performance is analyzed by a two-tone test. Two non-harmonically related audio signals are used to conduct a two-tone test.

5. G4 �Amateur Radio Practices G4A Amplifier tuning and neutralization A pronounced dip on the plate current meter reading of a vacuum tube RF power amplifier indicates correct adjustment of the plate tuning control. Dip means in the negative direction or less. The correct adjustment for the "Load" or "Coupling" control of a vacuum tube RF power amplifier is maximum power output without exceeding maximum allowable plate current. Too much current can cause overheating Could void warranty

6. G4 �Amateur Radio Practices

7. G4 �Amateur Radio Practices

8. G4 �Amateur Radio Practices G4A Amplifier tuning and neutralization (cont) A technique called, Negative feedback, is used to neutralize an RF amplifier. A neutralizing circuit cancels the effects of positive feedback in an RF amplifier. The reason for neutralizing the final amplifier stage of a transmitter is to eliminate self-oscillations.

9. G4 �Amateur Radio Practices G4A Digital Signal Processing (DSP) One use for a DSP in an amateur station is to remove noise from received signals. The following is needed for a DSP IF filter: An Analog to Digital Converter Digital to Analog Converter A Digital Processor Chip [All of the these answers are correct] DSP filtering is accomplished by converting the signal from analog to digital and using digital processing.

10. G4 �Amateur Radio Practices G4A Digital Signal Processing (DSP) (cont) An advantage of a receiver IF filter created with a DSP as compared to an analog filter is a wide range of filter bandwidths and shapes can be created. A DSP filter performs automatic notching of interfering carriers.

11. G4 �Amateur Radio Practices G4B Test and monitoring equipment A signal tracer may normally be used to identify an inoperative stage in a receiver. One measurement that can be made with a dip meter is the resonant frequency of a circuit.

12. G4 �Amateur Radio Practices G4B Test and monitoring equipment (cont) An antenna and feedline must be connected to an antenna analyzer when it is being used for SWR measurements. Standing Wave Ratio can be measured with a directional wattmeter.

13. G4 �Amateur Radio Practices G4B Test and monitoring equipment (cont) The power output of a transmitter must be raised approximately 4 times (~4X) to change the "S" meter reading on a distant receiver from S8 to S9.

14. G4 �Amateur Radio Practices G4B Oscilloscope An oscilloscope has horizontal and vertical channel amplifiers.

15. G4 �Amateur Radio Practices G4B Oscilloscope (cont) A monitoring oscilloscope is the best instrument to use to check the keying waveform of a CW transmitter. The signal connected to the vertical input of a monitoring oscilloscope when checking the quality of a transmitted signal is the attenuated RF output of the transmitter.

16. G4 �Amateur Radio Practices G4B Oscilloscope (cont) An advantage of an oscilloscope versus a digital voltmeter is that complex waveforms can be measured.

17. G4 �Amateur Radio Practices G4B Voltmeter An advantage of a digital voltmeter as compared to an analog voltmeter is significantly better precision for most uses. High input impedance is desirable for a voltmeter to decrease the loading on circuits being measured.

18. G4 �Amateur Radio Practices G4B Noise Bridge A noise bridge is normally connected between a receiver and an antenna of unknown impedance and is adjusted for minimum noise. One way a noise bridge might be used is for pre-tuning an antenna tuner.

19. G4 �Amateur Radio Practices G4B Field Strength Meter A field-strength meter may be used to monitor relative RF output when making antenna and transmitter adjustments. The radiation pattern of an antenna can be determined with a field strength meter. One use of a field strength meter might be close-in radio direction finding.

20. G4 �Amateur Radio Practices G4C Interference with consumer electronics A bypass capacitor might be useful in reducing RF interference to audio-frequency devices.

21. G4 �Amateur Radio Practices Interference with consumer electronics (cont) Reducing RF interference.

22. G4 �Amateur Radio Practices G4C Interference with consumer electronics (cont) An RFI filter at the affected telephone should be installed if a properly operating amateur station is interfering with a nearby telephone. A reason to place ferrite beads around audio cables to reduce common mode RF interference, is they act as a series inductor.

23. G4 �Amateur Radio Practices G4C Interference with consumer electronics (cont) Distorted speech is heard from a public-address system if there is interference from a nearby single-sideband phone transmitter. On-and-off humming or clicking is the effect on a public-address system if there is interference from nearby CW transmitter. Induced currents in conductors that are in poor electrical contact can cause unintended rectification of RF signal energy and can result in interference to your station as well as nearby radio and TV receivers. Arcing at a poor electrical connection is one cause of broadband radio frequency interference at an amateur radio station.

24. G4 �Amateur Radio Practices G4C Grounding If you receive an RF burn when touching your equipment while transmitting on a HF band, assuming the equipment is connected to a ground rod, the problem might be that the ground wire is resonant. Important reasons to have a good station ground are: To reduce the likelihood of RF burns To reduce the likelihood of electrical shock To reduce interference [All of these answers are correct]

25. G4 �Amateur Radio Practices G4C Grounding (cont) RF hot spots can occur in a station located above the ground floor if the equipment is grounded by a long ground wire. Electrical safety inside the ham shack is covered in the National Electrical Code. Keeping the station's ground wire as short as possible is one good way to avoid stray RF energy in an amateur station.

26. G4 �Amateur Radio Practices G4C Grounding (cont) Keeping the station's ground wire as short as possible is one good way to avoid stray RF energy in an amateur station. A ground loop can be avoided by connecting all ground conductors to a single point

27. G4 �Amateur Radio Practices Grounding (cont)

28. G4 �Amateur Radio Practices G4D Speech processors A speech processor increases the average power of a transmitted single sideband signal The reason for using a properly adjusted speech processor with a single sideband phone transmitter is it improves signal intelligibility at the receiver.

29. G4 �Amateur Radio Practices G4D Speech processors (cont) Each of the following can be the result of an incorrectly adjusted speech processor: Distorted speech Splatter Excessive background pickup [All of these answers are correct]

30. G4 �Amateur Radio Practices G4D S meters An S-meter measures the received signal strength. Assuming a properly calibrated S meter, an S-meter reading of 20 db over S-9 is 100 times stronger than an S-9 signal. An S-meter is generally found in a receiver.

31. G4 �Amateur Radio Practices G4D Common Connectors A �Type-N� connector is a moisture resistant RF connector useful to 10 GHz An UHF type connector is commonly used for RF service at frequencies up to 150�MHz. An RCA Phono type connector is commonly used for audio signals in amateur radio stations.

32. G4 �Amateur Radio Practices

33. G4 �Amateur Radio Practices

34. G4 �Amateur Radio Practices

35. G4 �Amateur Radio Practices

36. G4 �Amateur Radio Practices

37. G4 �Amateur Radio Practices G4D Common Connectors (cont) A DB-9 type connector would be a good choice for a serial data port. The main reason to use keyed connectors over non-keyed types is reduced chance of damage due to incorrect mating.

38. G4 �Amateur Radio Practices

39. G4 �Amateur Radio Practices G4E HF mobile radio installations All of the following emission types are permissible while operating HF mobile: CW SSB FM [All of these choices are correct]

40. G4 �Amateur Radio Practices G4E HF mobile radio installations (cont) An alternator whine is a tone or buzz in transmitted or received audio that varies with engine speed. A direct, fused connection, to the battery using heavy gauge wire, would be the best for a 100-watt HF mobile installation.

41. G4 �Amateur Radio Practices G4E HF mobile radio installations (cont) It is NOT best to draw the DC power for a 100-watt HF transceiver from an automobile's cigarette lighter socket (Think power formula) The socket's wiring may be inadequate for the current being drawn by the transceiver. The HF mobile antenna system that would most limit the effectiveness of an HF mobile transceiver would be an antenna operating in the 75-meter band. (Think frequency and length of antenna)

42. G4 �Amateur Radio Practices G4E Emergency and battery powered operation For an emergency generator installation, the generator should be located in a well ventilated area. A lead-acid storage battery might give off explosive hydrogen gas when being charged. Photovoltaic conversion is the name of the process by which sunlight is changed directly into electricity. The approximate open-circuit voltage from a modern, well illuminated photovoltaic cell is 0.5 VDC.

43. G4 �Amateur Radio Practices G4E Emergency and battery powered operation (cont) Doped Silicon material is used as the active element of a solar cell. A disadvantage to using wind power as the primary source of power for an emergency station is a large energy storage system is needed to supply power when the wind is not blowing. Danger of carbon monoxide poisoning is a primary reason for not placing a gasoline-fueled generator inside an occupied area. It may unwise to power your station by back feeding the output of a gasoline generator into your house wiring by connecting the generator through an AC wall outlet because it might present a hazard for electric company workers.

44. Element 3 General Class Question Pool

45. G4A01 Which of the following is one use for a DSP in an amateur station? To provide adequate grounding To remove noise from received signals To increase antenna gain To increase antenna bandwidth

46. G4A02 Which of the following instruments may be used to measure the output of a single-sideband transmitter when performing a two-tone test of amplitude linearity? An audio distortion analyzer An oscilloscope A directional wattmeter A high impedance audio voltmeter 

47. G4A03 Which of the following is needed for a DSP IF filter? An Analog to Digital Converter Digital to Analog Converter A Digital Processor Chip All of the these answers are correct

48. G4A04 Which of the following is an advantage of a receiver IF filter created with a DSP as compared to an analog filter? A wide range of filter bandwidths and shapes can be created Fewer digital components are required Mixing products are greatly reduced The DSP filter is much more effective at VHF frequencies

49. G4A05 How is DSP filtering accomplished? By using direct signal phasing By converting the signal from analog to digital and using digital processing By up-converting the signal to VHF By converting the signal from digital to analog and taking the difference of mixing products 

50. G4A06 What reading on the plate current meter of a vacuum tube RF power amplifier indicates correct adjustment of the plate tuning control? A pronounced peak A pronounced dip No change will be observed A slow, rhythmic oscillation 

51. G4A07 What is the correct adjustment for the "Load" or "Coupling" control of a vacuum tube RF power amplifier? Minimum SWR on the antenna Minimum plate current without exceeding maximum allowable grid current Highest plate voltage while minimizing grid current Maximum power output without exceeding maximum allowable plate current 

52. G4A08 Which of the following techniques is used to neutralize an RF amplifier? Feed-forward compensation Feed-forward cancellation Negative feedback Positive feedback

53. G4A09 What does a neutralizing circuit do in an RF amplifier? It controls differential gain It cancels the effects of positive feedback It eliminates AC hum from the power supply It reduces incidental grid modulation 

54. G4A10 What is the reason for neutralizing the final amplifier stage of a transmitter? To limit the modulation index To eliminate self oscillations To cut off the final amplifier during standby periods To keep the carrier on frequency 

55. G4A11 What type of transmitter performance does a two-tone test analyze? Linearity Carrier and undesired sideband suppression Percentage of frequency modulation Percentage of carrier phase shift 

56. G4A12 What type of signals are used to conduct a two-tone test? Two audio signals of the same frequency shifted 90-degrees Two non-harmonically related audio signals Two swept frequency tones Two audio frequency range square wave signals of equal amplitude 

57. G4A13 Which of the following performs automatic notching of interfering carriers? Band pass tuning A DSP filter Balanced mixing A noise limiter

58. G4B01 What item of test equipment contains horizontal and vertical channel amplifiers? An ohmmeter A signal generator An ammeter An oscilloscope 

59. G4B02 Which of the following is an advantage of an oscilloscope versus a digital voltmeter? An oscilloscope uses less power Complex impedances can be easily measured Input impedance is much lower Complex waveforms can be measured 

60. G4B03 How would a signal tracer normally be used? To identify the source of radio transmissions To make exact drawings of signal waveforms To show standing wave patterns on open-wire feed-lines To identify an inoperative stage in a receiver 

61. G4B04 How is a noise bridge normally used? It is connected at an antenna's feed point and reads the antenna's noise figure It is connected between a transmitter and an antenna and tuned for minimum SWR It is connected between a receiver and an antenna of unknown impedance and is adjusted for minimum noise It is connected between an antenna and ground and tuned for minimum SWR 

62. G4B05 Which of the following is the best instrument to use to check the keying waveform of a CW transmitter? A monitoring oscilloscope A field-strength meter A sidetone monitor A wavemeter 

63. G4B06 What signal source is connected to the vertical input of a monitoring oscilloscope when checking the quality of a transmitted signal? The local oscillator of the transmitter The audio input of the transmitter The transmitter balanced mixer output The attenuated RF output of the transmitter 

64. G4B07 What is an advantage of a digital voltmeter as compared to an analog voltmeter? Better for measuring computer circuits Better for RF measurements Significantly better precision for most uses Faster response

65. G4B08 What instrument may be used to monitor relative RF output when making antenna and transmitter adjustments? A field-strength meter An antenna noise bridge A multimeter A Q meter 

66. G4B09 How much must the power output of a transmitter be raised�to change the "S" meter reading on a distant receiver from S8 to S9? Approximately 2 times Approximately 3 times Approximately 4 times Approximately 5 times 

67. G4B10 Which of the following can be determined with a field strength meter? The radiation resistance of an antenna The radiation pattern of an antenna The presence and amount of phase distortion of a transmitter The presence and amount of amplitude distortion of a transmitter 

68. G4B11 Which of the following might be a use for a field strength meter? Close-in radio direction-finding A modulation monitor for a frequency or phase modulation transmitter An overmodulation indicator for a SSB transmitter A keying indicator for a RTTY or packet transmitter 

69. G4B12 What is one way a noise bridge might be used? Determining an antenna's gain in dBi Pre-tuning an antenna tuner Pre-tuning a linear amplifier Determining the line loss of the antenna system 

70. G4B13 What is one measurement that can be made with a dip meter? The resonant frequency of a circuit The tilt of the ionosphere The gain of an antenna The notch depth of a filter

71. G4B14 Which of the following must be connected to an antenna analyzer when it is being used for SWR measurements? Receiver Transmitter Antenna and feedline All of these answers are correct 

72. G4B15 Which of the following can be measured with a directional wattmeter? Standing Wave Ratio Antenna front-to-back ratio RF interference Radio wave propagation

73. G4B16 Why is high input impedance desirable for a voltmeter? It improves the frequency response It decreases battery consumption in the meter It improves the resolution of the readings It decreases the loading on circuits being measured 

74. G4C01 Which of the following might be useful in reducing RF interference to audio-frequency devices? Bypass inductor Bypass capacitor Forward-biased diode Reverse-biased diode

75. G4C02 Which of the following should be installed if a properly operating amateur station is interfering with a nearby telephone? An RFI filter on the transmitter An RFI filter at the affected telephone A high pass filter on the transmitter A high pass filter at the affected telephone 

76. G4C03 What sound is heard from a public-address system if there is interference from a nearby single-sideband phone transmitter? A steady hum whenever the transmitter is on the air On-and-off humming or clicking Distorted speech Clearly audible speech 

77. G4C04 What is the effect on a public-address system if there is interference from nearby CW transmitter? On-and-off humming or clicking A CW signal at a nearly pure audio frequency A chirpy CW signal Severely distorted audio 

78. G4C05 What might be the problem if you receive an RF burn when touching your equipment while transmitting on a HF band, assuming the equipment is connected to a ground rod? Flat braid rather than round wire has been used for the ground wire Insulated wire has been used for the ground wire The ground rod is resonant The ground wire is resonant 

79. G4C06 Which of the following is an important reason to have a good station ground? To reduce the likelihood of RF burns To reduce the likelihood of electrical shock To reduce interference All of these answers are correct 

80. G4C07 What is one good way to avoid stray RF energy in an amateur station? Keep the station's ground wire as short as possible Install an RF filter in series with the ground wire Use a ground loop for best conductivity Install a few ferrite beads on the ground wire where it connects to your station 

81. G4C08 Which of the following is a reason to place ferrite beads around audio cables to reduce common mode RF interference? They act as a series inductor They act as a shunt capacitor They lower the impedance of the cable They increase the admittance of the cable

82. G4C09 Which of the following statements about station grounding is true? The chassis of each piece of station equipment should be tied together with high-impedance conductors If the chassis of all station equipment is connected with a good conductor, there is no need to tie them to an earth ground RF hot spots can occur in a station located above the ground floor if the equipment is grounded by a long ground wire A ground loop is an effective way to ground station equipment 

83. G4C10 Which of the following is covered in the National Electrical Code? Acceptable bandwidth limits Acceptable modulation limits Electrical safety inside the ham shack RF exposure limits of the human body 

84. G4C11 Which of the following can cause unintended rectification of RF signal energy and can result in interference to your station as well as nearby radio and TV receivers? Induced currents in conductors that are in poor electrical contact Induced voltages in conductors that are in good electrical contact Capacitive coupling of the RF signal to ground Excessive standing wave ratio (SWR) of the transmission line system 

85. G4C12 What is one cause of broadband radio frequency interference at an amateur radio station? Not using a balun or line isolator to feed balanced antennas Lack of rectification of the transmitter's signal in power conductors Arcing at a poor electrical connection The use of horizontal, rather than vertical antennas 

86. G4C13 How can a ground loop be avoided? Series connect all ground conductors Connect the AC neutral conductor to the ground wire Avoid using lock washers and star washers in making ground connections Connect all ground conductors to a single point 

87. G4D01 What is the reason for using a properly adjusted speech processor with a single sideband phone transmitter? It reduces average transmitter power requirements It reduces unwanted noise pickup from the microphone It improves voice-frequency fidelity It improves signal intelligibility at the receiver 

88. G4D02 Which of the following describes how a speech processor affects a transmitted single sideband signal? It increases the peak power It increases the average power It reduces harmonic distortion It reduces intermodulation distortion

89. G4D03 Which of the following can be the result of an incorrectly adjusted speech processor? Distorted speech Splatter Excessive background pickup All of these answers are correct  

90. G4D04 What does an S-meter measure? Conductance Impedance Received signal strength Transmitter power output

91. G4D05 How does an S-meter reading of 20 db over S-9 compare to an S-9 signal, assuming a properly calibrated S meter? It is 10 times weaker It is 20 times weaker It is 20 times stronger It is 100 times stronger 

92. G4D06 Where is an S-meter generally found? In a receiver In a SWR bridge In a transmitter In a conductance bridge

93. G4D07 Which of the following describes a Type-N connector? A moisture resistant RF connector useful to 10 GHz A small bayonet connector used for data circuits A threaded connector used for hydraulic systems An audio connector used in surround sound installations 

94. G4D08 Which of the following connectors would be a good choice for a serial data port? PL-259 Type N Type SMA DB-9 

95. G4D09 Which of these connector types is commonly used for RF service at frequencies up to 150 MHz? Octal RJ-11 UHF DB-25 

96. G4D10 Which of these connector types is commonly used for audio signals in amateur radio stations? PL-259 BNC RCA Phono Type N 

97. G4D11 What is the main reason to use keyed connectors over non-keyed types? Prevention of use by unauthorized persons Reduced chance of damage due to incorrect mating Higher current carrying capacity All of these choices are correct

98. G4E01 Which of the following emission types are permissible while operating HF mobile? CW SSB FM All of these choices are correct

99. G4E02 What is alternator whine? A DC emission from the alternator A constant pitched tone or buzz in transmitted or received audio that occurs whenever the ignition key is in the on position A tone or buzz in transmitted or received audio that varies with engine speed A mechanical sound from the alternator indicating current overload 

100. G4E03 Which of the following power connections would be the best for a 100-watt HF mobile installation? A direct, fused connection to the battery using heavy gauge wire A direct, fused connection to the alternator or generator using heavy gauge wire A direct, fused connection to the battery using resistor wire A direct, fused connection to the alternator or generator using resistor wire

101. G4E04 Why is it best NOT to draw the DC power for a 100-watt HF transceiver from an automobile's cigarette lighter socket? The socket is not wired with an RF-shielded power cable The socket's wiring may be inadequate for the current being drawn by the transceiver The DC polarity of the socket is reversed from the polarity of modern HF transceivers The power from the socket is never adequately filtered for HF transceiver operation 

102. G4E05 Which of the following most limits the effectiveness of an HF mobile transceiver operating in the 75 meter band? �Picket Fencing� signal variation The wire gauge of the DC power line to the transceiver The HF mobile antenna system FCC rules limiting mobile output power on the 75 meter band 

103. G4E06 Which of the following is true of an emergency generator installation? The generator should be located in a well ventilated area The generator should be insulated from ground Fuel should be stored near the generator for rapid refueling in case of an emergency All of these choices are correct

104. G4E07 When might a lead-acid storage battery give off explosive hydrogen gas? When stored for long periods of time When being discharged When being charged When not placed on a level surface 

105. G4E08 What is the name of the process by which sunlight is changed directly into electricity? Photovoltaic conversion Photon emission Photosynthesis Photon decomposition  

106. G4E09 What is the approximate open-circuit voltage from a modern, well illuminated photovoltaic cell? 0.02 VDC 0.5 VDC 0.2 VDC .38 VDC 

107. G4E10 Which of these materials is used as the active element of a solar cell? Doped Silicon Nickel Hydride Doped Platinum Aluminum nitride 

108. G4E11 Which of the following is a disadvantage to using wind power as the primary source of power for an emergency station? The conversion efficiency from mechanical energy to electrical energy is less that 2 percent The voltage and current ratings of such systems are not compatible with amateur equipment A large energy storage system is needed to supply power when the wind is not blowing All of these choices are correct 

109. G4E12 Which of the following is a primary reason for not placing a gasoline-fueled generator inside an occupied area? Danger of carbon monoxide poisoning Danger of engine over torque Lack of oxygen for adequate combustion Lack of nitrogen for adequate combustion 

110. G4E13 Why would it be unwise to power your station by back feeding the output of a gasoline generator into your house wiring by connecting the generator through an AC wall outlet? It might present a hazard for electric company workers It is prone to RF interference It may disconnect your RF ground None of the above; this is an excellent expedient