G4A: Two-tone Test; amplifier tuning and neutralization; DSP
G4A01:
Which of the following is one use for a DSP in an amateur station?
To remove noise from received signals
To provide adequate grounding
To increase antenna gain
To increase antenna bandwidth
G4A02:
Which of the following instruments may be used to measure the output of a single-sideband transmitter when performing a two-tone test of amplitude linearity?
An oscilloscope
An audio distortion analyzer
A directional wattmeter
A high impedance audio voltmeter
G4A03:
Which of the following is needed for a DSP IF filter?
All of the these answers are correct
An Analog to Digital Converter
Digital to Analog Converter
A Digital Processor Chip
G4A04:
Which of the following is an advantage of a receiver IF filter created with a DSP as compared to an analog filter?
A wide range of filter bandwidths and shapes can be created
Fewer digital components are required
Mixing products are greatly reduced
The DSP filter is much more effective at VHF frequencies
G4A05:
How is DSP filtering accomplished?
By converting the signal from analog to digital and using digital processing
By using direct signal phasing
By up-converting the signal to VHF
By converting the signal from digital to analog and taking the difference of mixing products
G4A06:
What reading on the plate current meter of a vacuum tube RF power amplifier indicates correct adjustment of the plate tuning control?
A pronounced dip
A pronounced peak
No change will be observed
A slow, rhythmic oscillation
G4A07:
What is the correct adjustment for the "Load" or "Coupling" control of a vacuum tube RF power amplifier?
Maximum power output without exceeding maximum allowable plate current
Minimum SWR on the antenna
Minimum plate current without exceeding maximum allowable grid current
Highest plate voltage while minimizing grid current
G4A08:
Which of the following techniques is used to neutralize an RF amplifier?
Negative feedback
Feed-forward compensation
Feed-forward cancellation
Positive feedback
G4A09:
What does a neutralizing circuit do in an RF amplifier?
It cancels the effects of positive feedback
It controls differential gain
It eliminates AC hum from the power supply
It reduces incidental grid modulation
G4A10:
What is the reason for neutralizing the final amplifier stage of a transmitter?
To eliminate self oscillations
To limit the modulation index
To cut off the final amplifier during standby periods
To keep the carrier on frequency
G4A11:
What type of transmitter performance does a two-tone test analyze?
Linearity
Carrier and undesired sideband suppression
Percentage of frequency modulation
Percentage of carrier phase shift
G4A12:
What type of signals are used to conduct a two-tone test?
Two non-harmonically related audio signals
Two audio signals of the same frequency shifted 90-degrees
Two swept frequency tones
Two audio frequency range square wave signals of equal amplitude
G4A13:
Which of the following performs automatic notching of interfering carriers?
A DSP filter
Band pass tuning
Balanced mixing
A noise limiter
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