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