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396 lines
6.6 KiB
Plaintext
396 lines
6.6 KiB
Plaintext
% FILENAME = N17.TXT
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% Receiver Operation
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% Release version 3, October 2001
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% Q 23 modified 6 Mar 2012
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%QUESTION: 1
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#17.1 The frequency stability of a receiver is its ability to:
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stay tuned to the desired signal
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track the incoming signal as it drifts
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provide a frequency standard
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provide a digital readout
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% ans 1
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%QUESTION: 2
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#17.2 The sensitivity of a receiver specifies:
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the bandwidth of the RF preamplifier
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the stability of the oscillator
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its ability to receive weak signals
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its ability to reject strong signals
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% ans 3
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%QUESTION: 3
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#17.3 Of two receivers, the one capable of receiving the weakest signal will have:
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an RF gain control
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the least internally-generated noise
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the loudest audio output
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the greatest tuning range
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% ans 2
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%QUESTION: 4
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#17.4 The figure in a receiver's specifications which indicates its sensitivity is the:
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bandwidth of the IF in kilohertz
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audio output in watts
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signal plus noise to noise ratio
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number of RF amplifiers
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% ans 3
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%QUESTION: 5
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#17.5 If two receivers are compared, the more sensitive receiver will produce:
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more than one signal
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less signal and more noise
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more signal and less noise
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a steady oscillator drift
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% ans 3
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%QUESTION: 6
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#17.6 The ability of a receiver to separate signals close in frequency is called its:
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noise figure
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sensitivity
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bandwidth
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selectivity
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% ans 4
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%QUESTION: 7
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#17.7 A receiver with high selectivity has a:
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wide bandwidth
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wide tuning range
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narrow bandwidth
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narrow tuning range
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% ans 3
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%QUESTION: 8
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#17.8 The BFO in a superhet receiver operates on a frequency nearest to that of its:
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RF amplifier
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audio amplifier
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local oscillator
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IF amplifier
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% ans 4
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%QUESTION: 9
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#17.9 To receive Morse code signals, a BFO is employed in a superhet receiver to:
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produce IF signals
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beat with the local oscillator signal to produce sidebands
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produce an audio tone to beat with the IF signal
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beat with the IF signal to produce an audio tone
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% ans 4
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%QUESTION: 10
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#17.10 The following transmission mode is usually demodulated by a product detector:
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pulse modulation
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double sideband full carrier modulation
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frequency modulation
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single sideband suppressed carrier modulation
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% ans 4
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%QUESTION: 11
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#17.11 A superhet receiver for SSB reception has an insertion oscillator to:
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replace the suppressed carrier for detection
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phase out the unwanted sideband signal
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reduce the passband of the IF stages
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beat with the received carrier to produce the other sideband
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% ans 1
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%QUESTION: 12
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#17.12 A stage in a receiver with input and output circuits tuned to the received frequency is the:
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RF amplifier
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local oscillator
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audio frequency amplifier
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detector
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% ans 1
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%QUESTION: 13
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#17.13 An RF amplifier ahead of the mixer stage in a superhet receiver:
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enables the receiver to tune a greater frequency range
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means no BFO stage is needed
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makes it possible to receive SSB signals
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increases the sensitivity of the receiver
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% ans 4
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%QUESTION: 14
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#17.14 A communication receiver may have several IF filters of different bandwidths. The operator selects one to:
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improve the S-meter readings
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improve the receiver sensitivity
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improve the reception of different types of signal
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increase the noise received
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% ans 3
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%QUESTION: 15
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#17.15 The stage in a superhet receiver with a tuneable input and fixed tuned output is the:
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RF amplifier
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mixer stage
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IF amplifier
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local oscillator
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% ans 2
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%QUESTION: 16
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#17.16 The mixer stage of a superhet receiver:
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produces spurious signals
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produces an intermediate frequency signal
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acts as a buffer stage
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demodulates SSB signals
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% ans 2
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%QUESTION: 17
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#17.17 A 7 MHz signal and a 16 MHz oscillator are applied to a mixer stage. The output will contain the input frequencies and:
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8 and 9 MHz
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7 and 9 MHz
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9 and 23 MHz
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3.5 and 9 MHz
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% ans 3
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%QUESTION: 18
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#17.18 Selectivity in a superhet receiver is achieved primarily in the:
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RF amplifier
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Mixer
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IF amplifier
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Audio stage
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% ans 3
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%QUESTION: 19
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#17.19 The abbreviation AGC means:
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attenuating gain capacitor
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automatic gain control
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anode-grid capacitor
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amplified grid conductance
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% ans 2
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%QUESTION: 20
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#17.20 The AGC circuit in a receiver usually controls the:
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audio stage
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mixer stage
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power supply
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RF and IF stages
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% ans 4
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%QUESTION: 21
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#17.21 The tuning control of a superhet receiver changes the tuned frequency of the:
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audio amplifier
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IF amplifier
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local oscillator
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post-detector amplifier
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% ans 3
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%QUESTION: 22
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#17.22 A superhet receiver, with an IF at 500 kHz, is receiving a 14 MHz signal. The local oscillator frequency is:
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14.5 MHz
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19 MHz
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500 kHz
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28 MHz
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% ans 1
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%QUESTION: 23
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#17.23 An audio amplifier is necessary in an AM receiver because:
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signals leaving the detector are weak
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the carrier frequency must be replaced
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the signal requires demodulation
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RF signals are not heard by the human ear
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% ans 1
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%QUESTION: 24
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#17.24 The audio output transformer in a receiver is required to:
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step up the audio gain
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protect the loudspeaker from high currents
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improve the audio tone
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match the output impedance of the audio amplifier to the speaker
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% ans 4
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%QUESTION: 25
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#17.25 If the carrier insertion oscillator is counted, then a single conversion superhet receiver has:
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one oscillator
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two oscillators
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three oscillators
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four oscillators
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% ans 2
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%QUESTION: 26
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#17.26 A superhet receiver, with a 500 kHz IF, is receiving a signal at 21.0 MHz. A strong unwanted signal at 22 MHz is interfering. The cause is:
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insufficient IF selectivity
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the 22 MHz signal is out-of-band
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22 MHz is the image frequency
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insufficient RF gain
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% ans 3
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%QUESTION: 27
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#17.27 A superhet receiver receives an incoming signal of 3540 kHz and the local oscillator produces a signal of 3995 kHz. The IF amplifier is tuned to:
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455 kHz
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3540 kHz
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3995 kHz
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7435 kHz
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% ans 1
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%QUESTION: 28
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#17.28 A double conversion receiver designed for SSB reception has a carrier insertion oscillator and:
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one IF stage and one local oscillator
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two IF stages and one local oscillator
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two IF stages and two local oscillators
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two IF stages and three local oscillators
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% ans 3
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%QUESTION: 29
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#17.29 An advantage of a double conversion receiver is that it:
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does not drift off frequency
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produces a louder audio signal
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has improved image rejection characteristics
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is a more sensitive receiver
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% ans 3
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%QUESTION: 30
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#17.30 A receiver squelch circuit:
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automatically keeps the audio output at maximum level
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silences the receiver speaker during periods of no received signal
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provides a noisy operating environment
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is not suitable for pocket-size receivers
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% ans 2
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