G4 – AMATEUR RADIO PRACTICES [5 Exam Questions – 5 groups] 60 Questions Flashcards
“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
B. To reduce interference from carriers in the receiver passband
“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
C. It may be possible to reduce or eliminate interference from other signals
“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
C. By reducing receiver gain during a noise pulse
“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
B. A pronounced dip
“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
C. To prevent excessive drive
“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
C. Increase power transfer from the transmitter to the feed line
“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
A. Received signals may become distorted
“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
D. Desired power output without exceeding maximum allowable plate current
“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
C. To allow time for the amplifier to switch the antenna between the transceiver and the amplifier output
“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
B. Automatic generation of dots and dashes for CW operation
“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
B. The ALC action distorts the signal
“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
B. To permit full duplex operation – that is, transmitting and receiving at the same time
C. To transmit on one frequency and listen on another
D. To improve frequency accuracy by allowing variable frequency output (VFO) operation
C. To transmit on one frequency and listen on another
“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
A. To prevent receiver overload from strong incoming signals
“What item of test equipment contains horizontal and vertical channel amplifiers?”
A. An ohmmeter
B. A signal generator
C. An ammeter
D. An oscilloscope
D. An oscilloscope
“Which of the following is an advantage of an oscilloscope versus a digital voltmeter?”
A. An oscilloscope uses less power
B. Complex impedances can be easily measured
C. Greater precision
D. Complex waveforms can be measured
D. Complex waveforms can be measured
“Which of the following is the best instrument to use for checking the keying waveform of a CW transmitter?”
A. An oscilloscope
B. A field strength meter
C. A sidetone monitor
D. A wavemeter
A. An oscilloscope
“What signal source is connected to the vertical input of an oscilloscope when checking the RF envelope pattern of a transmitted signal?”
A. The local oscillator of the transmitter
B. An external RF oscillator
C. The transmitter balanced mixer output
D. The attenuated RF output of the transmitter
D. The attenuated RF output of the transmitter
“Why do voltmeters have high input impedance?”
A. It improves the frequency response
B. It allows for higher voltages to be safely measured
C. It improves the resolution of the readings
D. It decreases the loading on circuits being measured
D. It decreases the loading on circuits being measured
“What is an advantage of a digital multimeter as compared to an analog multimeter?”
A. Better for measuring computer circuits
B. Less prone to overload
C. Higher precision
D. Faster response
C. Higher precision
“What signals are used to conduct a two-tone test?”
A. Two audio signals of the same frequency shifted 90 degrees
B. Two non-harmonically related audio signals
C. Two swept frequency tones
D. Two audio frequency range square wave signals of equal amplitude
B. Two non-harmonically related audio signals
“What transmitter performance parameter does a two-tone test analyze?”
A. Linearity
B. Percentage of suppression of the carrier and undesired sideband for SSB
C. Percentage of frequency modulation
D. Percentage of carrier phase shift
A. Linearity
“When is an analog multimeter preferred to a digital multimeter?”
A. When testing logic circuits
B. When high precision is desired
C. When measuring the frequency of an oscillator
D. When adjusting circuits for maximum or minimum values
D. When adjusting circuits for maximum or minimum values
“Which of the following can be determined with a directional wattmeter?”
A. Standing wave ratio
B. Antenna front-to-back ratio
C. RF interference
D. Radio wave propagation
A. Standing wave ratio
“Which of the following must be connected to an antenna analyzer when it is being used for SWR measurements?”
A. Receiver
B. Transmitter
C. Antenna and feed line
D. All these choices are correct
C. Antenna and feed line