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320 lines
6.6 KiB
Plaintext
320 lines
6.6 KiB
Plaintext
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% FILENAME = N18.TXT
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% Transmitter Block Diagrams
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% Release version 3, October 2001
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%Question 1
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#18.1 In the transmitter block diagram shown, the "oscillator":
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<img src = "ssbtx.gif" align = center width = 483 height = 145>
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<totallines = 15 >
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is variable in frequency
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generates an audio frequency tone during tests
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uses a crystal for good frequency stability
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may have a calibrated dial
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% ans 3
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%Question 2
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#18.2 In the transmitter block diagram shown, the "balanced modulator":
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<img src = "ssbtx.gif" align = center width = 483 height = 145>
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<totallines = 15 >
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balances the high and low frequencies in the audio signal
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performs double sideband suppressed carrier modulation
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acts as a tone control
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balances the standing wave ratio
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% ans 2
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%Question 3
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#18.3 In the transmitter block diagram shown, the "filter":
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<img src = "ssbtx.gif" align = center width = 483 height = 145>
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<totallines = 15 >
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removes mains hum from the audio signal
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suppresses unwanted harmonics of the RF signal
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removes one sideband from the modulated signal
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removes the carrier component from the modulated signal
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% ans 3
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%Question 4
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#18.4 In the transmitter block diagram shown, the "mixer":
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<img src = "ssbtx.gif" align = center width = 483 height = 145>
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<totallines = 15 >
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adds the correct proportion of carrier to the SSB signal
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mixes the audio and RF signals in the correct proportions
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translates the SSB signal to the required frequency
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mixes the two sidebands in the correct proportions
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% ans 3
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%Question 5
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#18.5 In the transmitter block diagram shown, the "linear amplifier":
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<img src = "ssbtx.gif" align = center width = 483 height = 145>
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<totallines = 15 >
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has all components arranged in-line
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amplifies the modulated signal with no distortion
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aligns the two sidebands correctly
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removes any unwanted amplitude modulation from the signal
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% ans 2
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%Question 6
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#18.6 In the transmitter block diagram shown, the "VFO" is:
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<img src = "ssbtx.gif" align = center width = 483 height = 145>
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<totallines = 15 >
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a voice frequency oscillator
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a varactor fixed oscillator
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a virtual faze oscillator
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a variable frequency oscillator
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% ans 4
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%Question 7
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#18.7 In the transmitter block diagram shown, the "master oscillator" produces:
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<img src = "cwtx.gif" align = center width = 404 height = 163>
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<totallines = 13>
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a steady signal at the required carrier frequency
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a pulsating signal at the required carrier frequency
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a 800 Hz signal to modulate the carrier
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a modulated CW signal
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% ans 1
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%Question 8
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#18.8 In the transmitter block diagram shown, the "driver buffer":
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<img src = "cwtx.gif" align = center width = 404 height = 163>
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<totallines = 13>
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filters any sharp edges from the input signal
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drives the power amplifier into saturation
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provides isolation between the oscillator and power amplifier
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changes the frequency of the master oscillator signal
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% ans 3
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%Question 9
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#18.9 In the transmitter block diagram shown, the "Morse key":
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<img src = "cwtx.gif" align = center width = 404 height = 163>
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<totallines = 13>
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turns the DC power to the transmitter on and off
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allows the oscillator signal to pass only when the key is depressed
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changes the frequency of the transmitted signal when the key is
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depressed
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adds an 800 Hz audio tone to the signal when the key is depressed
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% ans 2
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%Question 10
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#18.10 In the transmitter block diagram shown, the "power amplifier":
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<img src = "cwtx.gif" align = center width = 404 height = 163>
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<totallines = 13 >
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need not have linear characteristics
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amplifies the bandwidth of its input signal
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must be adjusted during key-up conditions
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should be water-cooled
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% ans 1
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%Question 11
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#18.11 In the transmitter block diagram shown, the "speech amplifier":
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<img src = "fmtx.gif" align = center width = 600 height = 143>
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<totallines = 16 >
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amplifies the audio signal from the microphone
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is a spectral equalization entropy changer
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amplifies only speech, while discriminating against background noises
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shifts the frequency spectrum of the audio signal into the RF region
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% ans 1
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%Question 12
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#18.12 In the transmitter block diagram shown, the "modulator":
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<img src = "fmtx.gif" align = center width = 600 height = 143>
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<totallines = 16>
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is an amplitude modulator with feedback
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is an SSB modulator with feedback
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causes the speech waveform to gate the oscillator on and off
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causes the speech waveform to shift the frequency of the oscillator
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% ans 4
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%Question 13
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#18.13 In the transmitter block diagram shown, the "oscillator" is:
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<img src = "fmtx.gif" align = center width = 600 height = 143>
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<totallines = 16 >
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an audio frequency oscillator
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a variable frequency RF oscillator
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a beat frequency oscillator
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a variable frequency audio oscillator
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% ans 2
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%Question 14
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#18.14 In the transmitter block diagram shown, the "frequency multiplier":
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<img src = "fmtx.gif" align = center width = 600 height = 143>
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<totallines = 16 >
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translates the frequency of the modulated signal into the RF spectrum
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changes the frequency of the speech signal
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produces a harmonic of the oscillator signal
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multiplies the oscillator signal by the speech signal
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% ans 3
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%Question 15
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#18.15 In the transmitter block diagram shown, the "power amplifier":
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<img src = "fmtx.gif" align = center width = 600 height = 143>
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<totallines = 16 >
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increases the voltage of the mains to drive the antenna
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amplifies the audio frequency component of the signal
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amplifies the selected sideband to a suitable level
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amplifies the RF signal to a suitable level
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% ans 4
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%Question 16
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#18.16 The signal from an amplitude modulated transmitter consists of:
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a carrier and two sidebands
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a carrier and one sideband
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no carrier and two sidebands
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no carrier and one sideband
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% ans 1
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%Question 17
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#18.17 The signal from a frequency modulated transmitter has:
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an amplitude which varies with the modulating waveform
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a frequency which varies with the modulating waveform
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a single sideband which follows the modulating waveform
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no sideband structure
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% ans 2
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%Question 18
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#18.18 The signal from a balanced modulator consists of:
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a carrier and two sidebands
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a carrier and one sideband
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no carrier and two sidebands
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no carrier and one sideband
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% ans 3
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%Question 19
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#18.19 The signal from a CW transmitter consists of:
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a continuous, unmodulated RF waveform
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a continuous RF waveform modulated with an 800 Hz Morse signal
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an RF waveform which is keyed on and off to form Morse characters
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a continuous RF waveform which changes frequency in synchronism with
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an applied Morse signal
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% ans 3
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%Question 20
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#18.20 The following signal can be amplified using a non-linear
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amplifier:
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SSB
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FM
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AM
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DSBSC
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% ans 2
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