69 lines
3.5 KiB
Markdown
69 lines
3.5 KiB
Markdown
G4E – Mobile and portable HF stations; alternative energy source operation
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- [[G4E01]] (C)
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What is the purpose of a capacitance hat on a mobile antenna? #card
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- A. To increase the power handling capacity of a whip antenna
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- B. To reduce radiation resistance
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- C. To electrically lengthen a physically short antenna
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- D. To lower the radiation angle
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- [[G4E02]] (D)
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What is the purpose of a corona ball on an HF mobile antenna? #card
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- A. To narrow the operating bandwidth of the antenna
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- B. To increase the “Q” of the antenna
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- C. To reduce the chance of damage if the antenna should strike an object
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- D. To reduce RF voltage discharge from the tip of the antenna while transmitting
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- [[G4E03]] (A)
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Which of the following direct, fused power connections would be the best for a 100-watt HF mobile installation? #card
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- A. To the battery using heavy-gauge wire
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- B. To the alternator or generator using heavy-gauge wire
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- C. To the battery using insulated heavy duty balanced transmission line
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- D. To the alternator or generator using insulated heavy duty balanced transmission line
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- [[G4E04]] (B)
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Why should DC power for a 100-watt HF transceiver not be supplied by a vehicle’s auxiliary power socket? #card
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- A. The socket is not wired with an RF-shielded power cable
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- B. The socket’s wiring may be inadequate for the current drawn by the transceiver
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- C. The DC polarity of the socket is reversed from the polarity of modern HF transceivers
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- D. Drawing more than 50 watts from this socket could cause the engine to overheat
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- [[G4E05]] (C)
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Which of the following most limits an HF mobile installation? #card
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- A. “Picket fencing”
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- B. The wire gauge of the DC power line to the transceiver
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- C. Efficiency of the electrically short antenna
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- D. FCC rules limiting mobile output power on the 75-meter band
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- [[G4E06]] (C)
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What is one disadvantage of using a shortened mobile antenna as opposed to a full-size antenna? #card
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- A. Short antennas are more likely to cause distortion of transmitted signals
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- B. Q of the antenna will be very low
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- C. Operating bandwidth may be very limited
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- D. Harmonic radiation may increase
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- [[G4E07]] (D)
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Which of the following may cause receive interference to an HF transceiver installed in a vehicle? #card
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- A. The battery charging system
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- B. The fuel delivery system
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- C. The control computers
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- D. All these choices are correct
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- [[G4E08]] (A)
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In what configuration are the individual cells in a solar panel connected together? #card
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- A. Series-parallel
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- B. Shunt
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- C. Bypass
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- D. Full-wave bridge
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- [[G4E09]] (B)
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What is the approximate open-circuit voltage from a fully illuminated silicon photovoltaic cell? #card
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- A. 0.02 VDC
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- B. 0.5 VDC
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- C. 0.2 VDC
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- D. 1.38 VDC
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- [[G4E10]] (B)
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Why should a series diode be connected between a solar panel and a storage battery that is being charged by the panel? #card
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- A. To prevent overload by regulating the charging voltage
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- B. To prevent discharge of the battery through the panel during times of low or no illumination
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- C. To limit the current flowing from the panel to a safe value
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- D. To prevent damage to the battery due to excessive voltage at high illumination levels
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- [[G4E11]] (D)
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What precaution should be taken when connecting a solar panel to a lithium iron phosphate battery? #card
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- A. Ground the solar panel outer metal framework
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- B. Ensure the battery is placed terminals-up
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- C. A series resistor must be in place
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- D. The solar panel must have a charge controller
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