SUBELEMENT G4 - AMATEUR RADIO PRACTICES Flashcards

1
Q

G4A01 (B)

What is the purpose of the “notch filter” found on many HF transceivers?

A

B. To reduce interference from carriers in the receiver passband

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2
Q

G4A02 (C)
What is one advantage of selecting the opposite or “reverse” sideband when receiving CW signals on a typical HF transceiver?

A

C. It may be possible to reduce or eliminate interference from other signals

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3
Q

G4A03 (C)

What is normally meant by operating a transceiver in “split” mode?

A

C. The transceiver is set to different transmit and receive frequencies

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4
Q

G4A04 (B)
What reading on the plate current meter of a vacuum tube RF power amplifier indicates correct adjustment of the plate tuning control?

A

B. A pronounced dip

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5
Q

G4A05 (C)

What is a reason to use Automatic Level Control (ALC) with an RF power amplifier?

A

C. To reduce distortion due to excessive drive

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6
Q

G4A06 (C)

What type of device is often used to match transmitter output impedance to an impedance not equal to 50 ohms?

A

C. Antenna coupler or antenna tuner

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7
Q

G4A07 (D)

What condition can lead to permanent damage to a solid-state RF power amplifier?

A

D. Excessive drive power

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8
Q

G4A08 (D)

What is the correct adjustment for the load or coupling control of a vacuum tube RF power amplifier?

A

D. Maximum power output without exceeding maximum allowable plate current

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9
Q

G4A09 (C)

Why is a time delay sometimes included in a transmitter keying circuit?

A

C. To allow time for transmit-receive changeover operations to complete properly before RF output is allowed

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10
Q

G4A10 (B)

What is the purpose of an electronic keyer?

A

B. Automatic generation of strings of dots and dashes for CW operation

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11
Q

G4A11 (A)

Which of the following is a use for the IF shift control on a receiver?

A

A. To avoid interference from stations very close to the receive frequency

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12
Q

G4A12 (C)

Which of the following is a common use for the dual VFO feature on a transceiver?

A

C. To permit monitoring of two different frequencies

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13
Q

G4A13 (A)

What is one reason to use the attenuator function that is present on many HF transceivers?

A

A. To reduce signal overload due to strong incoming signals

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14
Q

G4A14 (B)
What is likely to happen if a transceiver’s ALC system is not set properly when transmitting AFSK signals with the radio using single sideband mode?

A

B. Improper action of ALC distorts the signal and can cause spurious emissions

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15
Q

G4A15 (D)
Which of the following can be a symptom of transmitted RF being picked up by an audio cable carrying AFSK data signals between a computer and a transceiver?

A

A. The VOX circuit does not un-key the transmitter
B. The transmitter signal is distorted
C. Frequent connection timeouts
D. All of these choices are correct

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16
Q

G4B01 (D)

What item of test equipment contains horizontal and vertical channel amplifiers?

A

D. An oscilloscope

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17
Q

G4B02 (D)

Which of the following is an advantage of an oscilloscope versus a digital voltmeter?

A

D. Complex waveforms can be measured

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18
Q

G4B03 (A)

Which of the following is the best instrument to use when checking the keying waveform of a CW transmitter?

A

A. An oscilloscope

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19
Q

G4B04 (D)
What signal source is connected to the vertical input of an oscilloscope when checking the RF envelope pattern of a transmitted signal?

A

D. The attenuated RF output of the transmitter

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20
Q

G4B05 (D)

Why is high input impedance desirable for a voltmeter?

A

D. It decreases the loading on circuits being measured

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21
Q

G4B06 (C)

What is an advantage of a digital voltmeter as compared to an analog voltmeter?

A

C. Better precision for most uses

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22
Q

G4B07 (B)

What signals are used to conduct a two-tone test?

A

B. Two non-harmonically related audio signals

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23
Q

G4B08 (A)
Which of the following instruments may be used to monitor relative RF output when making antenna and transmitter adjustments?

A

A. A field strength meter

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24
Q

G4B09 (B)

Which of the following can be determined with a field strength meter?

A

B. The radiation pattern of an antenna

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25
Q

G4B10 (A)

Which of the following can be determined with a directional wattmeter?

A

A. Standing wave ratio

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26
Q

G4B11 (C)

Which of the following must be connected to an antenna analyzer when it is being used for SWR measurements?

A

C. Antenna and feed line

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27
Q

G4B12 (B)

What problem can occur when making measurements on an antenna system with an antenna analyzer?

A

B. Strong signals from nearby transmitters can affect the accuracy of measurements

28
Q

G4B13 (C)

What is a use for an antenna analyzer other than measuring the SWR of an antenna system?

A

C. Determining the impedance of an unknown or unmarked coaxial cable

29
Q

G4B14 (D)
What is an instance in which the use of an instrument with analog readout may be preferred over an instrument with a digital readout?

A

D. When adjusting tuned circuits

30
Q

G4B15 (A)

What type of transmitter performance does a two-tone test analyze?

A

A. Linearity

31
Q

G4C01 (B)

Which of the following might be useful in reducing RF interference to audio frequency devices?

A

B. Bypass capacitor

32
Q

G4C02 (C)

Which of the following could be a cause of interference covering a wide range of frequencies?

A

C. Arcing at a poor electrical connection

33
Q

G4C03 (C)
What sound is heard from an audio device or telephone if there is interference from a nearby single sideband phone transmitter?

A

C. Distorted speech

34
Q

G4C04 (A)

What is the effect on an audio device or telephone system if there is interference from a nearby CW transmitter?

A

A. On-and-off humming or clicking

35
Q

G4C05 (D)
What might be the problem if you receive an RF burn when touching your equipment while transmitting on an HF band, assuming the equipment is connected to a ground rod?

A

D. The ground wire has high impedance on that frequency

36
Q

G4C06 (C)

What effect can be caused by a resonant ground connection?

A

C. High RF voltages on the enclosures of station equipment

37
Q

G4C07 (A)

What is one good way to avoid unwanted effects of stray RF energy in an amateur station?

A

A. Connect all equipment grounds together

38
Q

G4C08 (A)

Which of the following would reduce RF interference caused by common-mode current on an audio cable?

A

A. Placing a ferrite choke around the cable

39
Q

G4C09 (D)

How can a ground loop be avoided?

A

D. Connect all ground conductors to a single point

40
Q

G4C10 (A)

What could be a symptom of a ground loop somewhere in your station?

A

A. You receive reports of “hum” on your station’s transmitted signal

41
Q

G4C11 (B)

Which of the following is a function of a digital signal processor?

A

B. To remove noise from received signals

42
Q

G4C12 (A)

Which of the following is an advantage of a receiver DSP IF filter as compared to an analog filter?

A

A. A wide range of filter bandwidths and shapes can be created

43
Q

G4C13 (B)

Which of the following can perform automatic notching of interfering carriers?

A

B. A Digital Signal Processor (DSP) filter

44
Q

G4D01 (A)

What is the purpose of a speech processor as used in a modern transceiver?

A

A. Increase the intelligibility of transmitted phone signals during poor conditions

45
Q

G4D02 (B)

Which of the following describes how a speech processor affects a transmitted single sideband phone signal?

A

B. It increases average power

46
Q

G4D03 (D)

Which of the following can be the result of an incorrectly adjusted speech processor?

A

A. Distorted speech
B. Splatter
C. Excessive background pickup
D. All of these choices are correct

47
Q

G4D04 (C)

What does an S meter measure?

A

C. Received signal strength

48
Q

G4D05 (D)
How does a signal that reads 20 dB over S9 compare to one that reads S9 on a receiver, assuming a properly calibrated S meter?

A

D. It is 100 times more powerful

49
Q

G4D06 (A)

Where is an S meter found?

A

A. In a receiver

50
Q

G4D07 (C)
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?

A

C. Approximately 4 times

51
Q

G4D08 (C)

What frequency range is occupied by a 3 kHz LSB signal when the displayed carrier frequency is set to 7.178 MHz?

A

C. 7.175 to 7.178 MHz

52
Q

G4D09 (B)

What frequency range is occupied by a 3 kHz USB signal with the displayed carrier frequency set to 14.347 MHz?

A

B. 14.347 to 14.350 MHz

53
Q

G4D10 (A)
How close to the lower edge of the 40-meter General Class phone segment should your displayed carrier frequency be when using 3 kHz wide LSB?

A

A. At least 3 kHz above the edge of the segment

54
Q

G4D11 (B)
How close to the upper edge of the 20-meter General Class band should your displayed carrier frequency be when using 3 kHz wide USB?

A

B. At least 3 kHz below the edge of the band

55
Q

G4E01 (C)

What is the purpose of a capacitance hat on a mobile antenna?

A

C. To electrically lengthen a physically short antenna

56
Q

G4E02 (D)

What is the purpose of a corona ball on a HF mobile antenna?

A

D. To reduce high voltage discharge from the tip of the antenna

57
Q

G4E03 (A)

Which of the following direct, fused power connections would be the best for a 100 watt HF mobile installation?

A

A. To the battery using heavy gauge wire

58
Q

G4E04 (B)

Why is it best NOT to draw the DC power for a 100 watt HF transceiver from a vehicle’s auxiliary power socket?

A

B. The socket’s wiring may be inadequate for the current drawn by the transceiver

59
Q

G4E05 (C)

Which of the following most limits the effectiveness of an HF mobile transceiver operating in the 75-meter band?

A

C. The antenna system

60
Q

G4E06 (C)

What is one disadvantage of using a shortened mobile antenna as opposed to a full size antenna?

A

C. Operating bandwidth may be very limited

61
Q

G4E07 (D)
Which of the following may cause interference to be heard in the receiver of an HF radio installed in a recent model vehicle?

A

D. All of these choices are correct

62
Q

G4E08 (A)

What is the name of the process by which sunlight is changed directly into electricity?

A

A. Photovoltaic conversion

63
Q

G4E09 (B)

What is the approximate open-circuit voltage from a fully illuminated silicon photovoltaic cell?

A

B. 0.5 VDC

64
Q

G4E10 (B)
What is the reason that a series diode is connected between a solar panel and a storage battery that is being charged by the panel?

A

B. The diode prevents self-discharge of the battery though the panel during times of low or no illumination

65
Q

G4E11 (C)

Which of the following is a disadvantage of using wind as the primary source of power for an emergency station?

A

C. A large energy storage system is needed to supply power when the wind is not blowing