80 lines
4.0 KiB
Markdown
80 lines
4.0 KiB
Markdown
G4A – Station configuration and operation
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- [[G4A01]] (B)
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What is the purpose of the notch filter found on many HF transceivers? #card
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- A. To restrict the transmitter voice bandwidth
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- B. To reduce interference from carriers in the receiver passband
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- C. To eliminate receiver interference from impulse noise sources
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- D. To remove interfering splatter generated by signals on adjacent frequencies
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- [[G4A02]] (C)
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What is the benefit of using the opposite or “reverse” sideband when receiving CW? #card
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- A. Interference from impulse noise will be eliminated
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- B. More stations can be accommodated within a given signal passband
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- C. It may be possible to reduce or eliminate interference from other signals
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- D. Accidental out-of-band operation can be prevented
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- [[G4A03]] (C)
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How does a noise blanker work? #card
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- A. By temporarily increasing received bandwidth
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- B. By redirecting noise pulses into a filter capacitor
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- C. By reducing receiver gain during a noise pulse
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- D. By clipping noise peaks
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- [[G4A04]] (B)
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What is the effect on plate current of the correct setting of a vacuum-tube RF power amplifier’s TUNE control? #card
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- A. A pronounced peak
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- B. A pronounced dip
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- C. No change will be observed
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- D. A slow, rhythmic oscillation
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- [[G4A05]] (C)
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Why is automatic level control (ALC) used with an RF power amplifier? #card
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- A. To balance the transmitter audio frequency response
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- B. To reduce harmonic radiation
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- C. To prevent excessive drive
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- D. To increase overall efficiency
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- [[G4A06]] (C)
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What is the purpose of an antenna tuner? #card
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- A. Reduce the SWR in the feed line to the antenna
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- B. Reduce the power dissipation in the feedline to the antenna
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- C. Increase power transfer from the transmitter to the feed line
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- D. All these choices are correct
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- [[G4A07]] (A)
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What happens as a receiver’s noise reduction control level is increased? #card
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- A. Received signals may become distorted
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- B. Received frequency may become unstable
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- C. CW signals may become severely attenuated
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- D. Received frequency may shift several kHz
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- [[G4A08]] (D)
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What is the correct adjustment for the LOAD or COUPLING control of a vacuum tube RF power amplifier? #card
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- A. Minimum SWR on the antenna
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- B. Minimum plate current without exceeding maximum allowable grid current
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- C. Highest plate voltage while minimizing grid current
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- D. Desired power output without exceeding maximum allowable plate current
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- [[G4A09]] (C)
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What is the purpose of delaying RF output after activating a transmitter’s keying line to an external amplifier? #card
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- A. To prevent key clicks on CW
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- B. To prevent transient overmodulation
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- C. To allow time for the amplifier to switch the antenna between the transceiver and the amplifier output
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- D. To allow time for the amplifier power supply to reach operating level
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- [[G4A10]] (B)
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What is the function of an electronic keyer? #card
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- A. Automatic transmit/receive switching
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- B. Automatic generation of dots and dashes for CW operation
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- C. To allow time for switching the antenna from the receiver to the transmitter
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- D. Computer interface for PSK and RTTY operation
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- [[G4A11]] (B)
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Why should the ALC system be inactive when transmitting AFSK data signals? #card
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- A. ALC will invert the modulation of the AFSK mode
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- B. The ALC action distorts the signal
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- C. When using digital modes, too much ALC activity can cause the transmitter to overheat
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- D. All these choices are correct
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- [[G4A12]] (C)
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Which of the following is a common use of the dual-VFO feature on a transceiver? #card
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- A. To allow transmitting on two frequencies at once
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- C. To transmit on one frequency and listen on another
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- D. To improve frequency accuracy by allowing variable frequency output (VFO) operation
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- [[G4A13]] (A)
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What is the purpose of using a receive attenuator? #card
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- A. To prevent receiver overload from strong incoming signals
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- B. To reduce the transmitter power when driving a linear amplifier
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- C. To reduce power consumption when operating from batteries
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- D. To reduce excessive audio level on strong signals
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