SUBELEMENT G4 - AMATEUR RADIO PRACTICES Flashcards by Mark Casburn

G4A01 (B)

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

B. To reduce interference from carriers in the receiver passband

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

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

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G4A03 (C)

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

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

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

B. A pronounced dip

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G4A05 (C)

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

C. To reduce distortion due to excessive drive

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G4A06 (C)

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

C. Antenna coupler or antenna tuner

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G4A07 (D)

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

D. Excessive drive power

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G4A08 (D)

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

D. Maximum power output without exceeding maximum allowable plate current

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G4A09 (C)

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

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

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G4A10 (B)

What is the purpose of an electronic keyer?

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

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G4A11 (A)

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

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

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G4A12 (C)

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

C. To permit monitoring of two different frequencies

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G4A13 (A)

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

A. To reduce signal overload due to strong incoming signals

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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?

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

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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. 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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G4B01 (D)

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

D. An oscilloscope

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G4B02 (D)

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

D. Complex waveforms can be measured

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G4B03 (A)

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

A. An oscilloscope

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

D. The attenuated RF output of the transmitter

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G4B05 (D)

Why is high input impedance desirable for a voltmeter?

D. It decreases the loading on circuits being measured

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G4B06 (C)

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

C. Better precision for most uses

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G4B07 (B)

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

B. Two non-harmonically related audio signals

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

A. A field strength meter

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G4B09 (B)

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

B. The radiation pattern of an antenna

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G4B10 (A) | Which of the following can be determined with a directional wattmeter?

A. Standing wave ratio

G4B11 (C) | Which of the following must be connected to an antenna analyzer when it is being used for SWR measurements?

C. Antenna and feed line

G4B12 (B) | What problem can occur when making measurements on an antenna system with an antenna analyzer?

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

G4B13 (C) | What is a use for an antenna analyzer other than measuring the SWR of an antenna system?

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

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?

D. When adjusting tuned circuits

G4B15 (A) | What type of transmitter performance does a two-tone test analyze?

A. Linearity

G4C01 (B) | Which of the following might be useful in reducing RF interference to audio frequency devices?

B. Bypass capacitor

G4C02 (C) | Which of the following could be a cause of interference covering a wide range of frequencies?

C. Arcing at a poor electrical connection

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

C. Distorted speech

G4C04 (A) | What is the effect on an audio device or telephone system if there is interference from a nearby CW transmitter?

A. On-and-off humming or clicking

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?

D. The ground wire has high impedance on that frequency

G4C06 (C) | What effect can be caused by a resonant ground connection?

C. High RF voltages on the enclosures of station equipment

G4C07 (A) | What is one good way to avoid unwanted effects of stray RF energy in an amateur station?

A. Connect all equipment grounds together

G4C08 (A) | Which of the following would reduce RF interference caused by common-mode current on an audio cable?

A. Placing a ferrite choke around the cable

G4C09 (D) | How can a ground loop be avoided?

D. Connect all ground conductors to a single point

G4C10 (A) | What could be a symptom of a ground loop somewhere in your station?

A. You receive reports of "hum" on your station's transmitted signal

G4C11 (B) | Which of the following is a function of a digital signal processor?

B. To remove noise from received signals

G4C12 (A) | Which of the following is an advantage of a receiver DSP IF filter as compared to an analog filter?

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

G4C13 (B) | Which of the following can perform automatic notching of interfering carriers?

B. A Digital Signal Processor (DSP) filter

G4D01 (A) | What is the purpose of a speech processor as used in a modern transceiver?

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

G4D02 (B) | Which of the following describes how a speech processor affects a transmitted single sideband phone signal?

B. It increases average power

G4D03 (D) | Which of the following can be the result of an incorrectly adjusted speech processor?

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

G4D04 (C) | What does an S meter measure?

C. Received signal strength

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?

D. It is 100 times more powerful

G4D06 (A) | Where is an S meter found?

A. In a receiver

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?

C. Approximately 4 times

G4D08 (C) | What frequency range is occupied by a 3 kHz LSB signal when the displayed carrier frequency is set to 7.178 MHz?

C. 7.175 to 7.178 MHz

G4D09 (B) | What frequency range is occupied by a 3 kHz USB signal with the displayed carrier frequency set to 14.347 MHz?

B. 14.347 to 14.350 MHz

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. At least 3 kHz above the edge of the segment

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?

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

G4E01 (C) | What is the purpose of a capacitance hat on a mobile antenna?

C. To electrically lengthen a physically short antenna

G4E02 (D) | What is the purpose of a corona ball on a HF mobile antenna?

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

G4E03 (A) | Which of the following direct, fused power connections would be the best for a 100 watt HF mobile installation?

A. To the battery using heavy gauge wire

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?

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

G4E05 (C) | Which of the following most limits the effectiveness of an HF mobile transceiver operating in the 75-meter band?

C. The antenna system

G4E06 (C) | What is one disadvantage of using a shortened mobile antenna as opposed to a full size antenna?

C. Operating bandwidth may be very limited

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?

D. All of these choices are correct

G4E08 (A) | What is the name of the process by which sunlight is changed directly into electricity?

A. Photovoltaic conversion

G4E09 (B) | What is the approximate open-circuit voltage from a fully illuminated silicon photovoltaic cell?

B. 0.5 VDC

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?

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

G4E11 (C) | Which of the following is a disadvantage of using wind as the primary source of power for an emergency station?

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

SUBELEMENT G4 - AMATEUR RADIO PRACTICES Flashcards

(65 cards)