006 - Receivers Flashcards
A-006-001-001
What are the advantages of the frequency conversion process in a superheterodyne receiver?
(a) Increased selectivity and optimal tuned circuit design
(b) Automatic detection in the RF amplifier and increased sensitivity
(c) Automatic soft-limiting and automatic squelching
(d) Automatic squelching and increased sensitivity
A-006-001-001
What are the advantages of the frequency conversion process in a superheterodyne receiver?
(a) Increased selectivity and optimal tuned circuit design
A-006-001-002
What factors should be considered when selecting an intermediate frequency?
(a) Noise figure and distortion
(b) Interference to other services
(c) Cross-modulation distortion and interference
(d) Image rejection and responses to unwanted signals
A-006-001-002
What factors should be considered when selecting an intermediate frequency?
(d) Image rejection and responses to unwanted signals
A-006-001-003
One of the greatest advantages of the double-conversion over the single-conversion receiver is that it:
(a) is much more stable
(b) is much more sensitive
(c) greater reduction of image interference for a given front end selectivity
(d) produces a louder signal at the output
A-006-001-003
One of the greatest advantages of the double-conversion over the single-conversion receiver is that it:
(c) greater reduction of image interference for a given front end selectivity
A-006-001-004
In a communications receiver, a crystal filter would be located in the:
(a) local oscillator
(b) audio output stage
(c) detector
(d) IF circuits
A-006-001-004
In a communications receiver, a crystal filter would be located in the:
(d) IF circuits
A-006-001-005
A multiple conversion superheterodyne receiver is more susceptible to spurious responses than a single-conversion receiver because of the:
(a) additional oscillators and mixing frequencies involved in the design
(b) poorer selectivity in the IF caused by the multitude of frequency changes
(c) greater sensitivity introducing higher levels of RF to the receiver
(d) AGC being forced to work harder causing the stages concerned to overload
A-006-001-005
A multiple conversion superheterodyne receiver is more susceptible to spurious responses than a single-conversion receiver because of the:
(a) additional oscillators and mixing frequencies involved in the design
A-006-001-006
In a dual-conversion superheterodyne receiver what are the respective aims of the first and second conversion:
(a) image rejection and selectivity
(b) selectivity and image rejection
(c) selectivity and dynamic range
(d) image rejection and noise figure
A-006-001-006
In a dual-conversion superheterodyne receiver what are the respective aims of the first and second conversion:
(a) image rejection and selectivity
A-006-001-007
Which stage of a receiver has its input and output circuits tuned to the received frequency?
(a) The local oscillator
(b) The audio frequency amplifier
(c) The detector
(d) The RF amplifier
A-006-001-007
Which stage of a receiver has its input and output circuits tuned to the received frequency?
(d) The RF amplifier
A-006-001-008
Which stage of a superheterodyne receiver lies between a tuneable stage and a fixed tuned stage?
(a) Radio frequency amplifier
(b) Mixer
(c) Intermediate frequency amplifier
(d) Local oscillator
A-006-001-008
Which stage of a superheterodyne receiver lies between a tuneable stage and a fixed tuned stage?
(b) Mixer
A-006-001-009
A single conversion receiver with a 9 MHz IF has a local oscillator operating at 16 MHz. The frequency it is tuned to is:
(a) 16 MHz
(b) 21 MHz
(c) 7 MHz
(d) 9 MHz
A-006-001-009
A single conversion receiver with a 9 MHz IF has a local oscillator operating at 16 MHz. The frequency it is tuned to is:
(c) 7 MHz
A-006-001-010
A double conversion receiver designed for SSB reception has a beat frequency oscillator and:
(a) one IF stage and one local oscillator
(b) two IF stages and two local oscillators
(c) two IF stages and three local oscillators
(d) two IF stages and one local oscillator
A-006-001-010
A double conversion receiver designed for SSB reception has a beat frequency oscillator and:
(b) two IF stages and two local oscillators
A-006-001-011
The advantage of a double conversion receiver over a single conversion receiver is that it:
(a) does not drift off frequency
(b) suffers less from image interference for a given front end sensitivity
(c) is a more sensitive receiver
(d) produces a louder audio signal
A-006-001-011
The advantage of a double conversion receiver over a single conversion receiver is that it:
(b) suffers less from image interference for a given front end sensitivity
A-006-002-001
The mixer stage of a superheterodyne receiver is used to:
(a) change the frequency of the incoming signal to that of the IF
(b) allow a number of IF frequencies to be used
(c) remove image signals from the receiver
(d) produce an audio frequency for the speaker
A-006-002-001
The mixer stage of a superheterodyne receiver is used to:
(a) change the frequency of the incoming signal to that of the IF
A-006-002-002
A superheterodyne receiver designed for SSB reception must have a beat-frequency oscillator (BFO) because:
(a) the suppressed carrier must be replaced for detection
(b) it phases out the unwanted sideband signal
(c) it reduces the pass-band of the IF stages
(d) it beats with the receiver carrier to produce the missing sideband
A-006-002-002
A superheterodyne receiver designed for SSB reception must have a beat-frequency oscillator (BFO) because:
(a) the suppressed carrier must be replaced for detection
A-006-002-003
The first mixer in the receiver mixes the incoming signal with the local oscillator to produce:
(a) an audio frequency
(b) an intermediate frequency
(c) a radio frequency
(d) a high frequency oscillator (HFO) frequency
A-006-002-003
The first mixer in the receiver mixes the incoming signal with the local oscillator to produce:
(b) an intermediate frequency
A-006-002-004
If the incoming signal to the mixer is 3 600 kHz and the first IF is 9 MHz, at which one of the following frequencies would the local oscillator (LO) operate?
(a) 3 400 kHz
(b) 10 600 kHz
(c) 21 600 kHz
(d) 5 400 kHz
A-006-002-004
If the incoming signal to the mixer is 3 600 kHz and the first IF is 9 MHz, at which one of the following frequencies would the local oscillator (LO) operate?
(d) 5 400 kHz
A-006-002-005
The BFO is off-set slightly (500 - 1 500 Hz) from the incoming signal to the detector. This is required:
(a) to pass the signal without interruption
(b) to beat with the incoming signal
(c) to provide additional amplification
(d) to protect the incoming signal from interference
A-006-002-005
The BFO is off-set slightly (500 - 1 500 Hz) from the incoming signal to the detector. This is required:
(b) to beat with the incoming signal
A-006-002-006
It is very important that the oscillators contained in a superheterodyne receiver are:
(a) sensitive and selective
(b) stable and sensitive
(c) selective and spectrally pure
(d) stable and spectrally pure
A-006-002-006
It is very important that the oscillators contained in a superheterodyne receiver are:
(d) stable and spectrally pure
A-006-002-007
In a superheterodyne receiver, a stage before the IF amplifier has a variable capacitor in parallel with a trimmer capacitor and an inductance. The variable capacitor is for:
(a) tuning of the local oscillator (LO)
(b) tuning both the antenna and the BFO
(c) tuning of the beat-frequency oscillator (BFO)
(d) tuning both the antenna and the LO
A-006-002-007
In a superheterodyne receiver, a stage before the IF amplifier has a variable capacitor in parallel with a trimmer capacitor and an inductance. The variable capacitor is for:
(a) tuning of the local oscillator (LO)
A-006-002-008
In a superheterodyne receiver without an RF amplifier, the input to the mixer stage has a variable capacitor in parallel with an inductance. The variable capacitor is for:
(a) tuning both the antenna and the beat-frequency oscillator
(b) tuning the beat-frequency oscillator
(c) tuning both the antenna and the local oscillator
(d) tuning the receiver preselector to the reception frequency
A-006-002-008
In a superheterodyne receiver without an RF amplifier, the input to the mixer stage has a variable capacitor in parallel with an inductance. The variable capacitor is for:
(d) tuning the receiver preselector to the reception frequency
A-006-002-009
What receiver stage combines a 14.25-MHz input signal with a 13.795-MHz oscillator signal to produce a 455-kHz intermediate frequency (IF) signal?
(a) Mixer
(b) BFO
(c) VFO
(d) Multiplier
A-006-002-009
What receiver stage combines a 14.25-MHz input signal with a 13.795-MHz oscillator signal to produce a 455-kHz intermediate frequency (IF) signal?
(a) Mixer
A-006-002-010
Which two stages in a superheterodyne receiver have input tuned circuits tuned to the same frequency?
(a) IF and local oscillator
(b) RF and first mixer
(c) RF and IF
(d) RF and local oscillator
A-006-002-010
Which two stages in a superheterodyne receiver have input tuned circuits tuned to the same frequency?
(b) RF and first mixer
A-006-002-011
The mixer stage of a superheterodyne receiver:
(a) produces spurious signals
(b) produces an intermediate frequency
(c) acts as a buffer stage
(d) demodulates SSB signals
A-006-002-011
The mixer stage of a superheterodyne receiver:
(b) produces an intermediate frequency
A-006-003-001
What is meant by the noise floor of a receiver?
(a) The weakest signal that can be detected under noisy atmospheric conditions
(b) The minimum level of noise that will overload the receiver RF amplifier stage
(c) The weakest signal that can be detected above the receiver internal noise
(d) The amount of noise generated by the receiver local oscillator
A-006-003-001
What is meant by the noise floor of a receiver?
(c) The weakest signal that can be detected above the receiver internal noise
A-006-003-002
Which of the following is a purpose of the first IF amplifier stage in a receiver?
(a) To improve selectivity and gain
(b) To tune out cross-modulation distortion
(c) To increase dynamic response
(d) To improve noise figure performance
A-006-003-002
Which of the following is a purpose of the first IF amplifier stage in a receiver?
(a) To improve selectivity and gain
A-006-003-003
How much gain should be used in the RF amplifier stage of a receiver?
(a) As much gain as possible, short of self-oscillation
(b) Sufficient gain to allow weak signals to overcome noise generated in the first mixer stage
(c) It depends on the amplification factor of the first IF stage
(d) Sufficient gain to keep weak signals below the noise of the first mixer stage
A-006-003-003
How much gain should be used in the RF amplifier stage of a receiver?
(b) Sufficient gain to allow weak signals to overcome noise generated in the first mixer stage
A-006-003-004
What is the primary purpose of an RF amplifier in a receiver?
(a) To improve the receiver noise figure
(b) To vary the receiver image rejection by using the AGC
(c) To develop the AGC voltage
(d) To provide most of the receiver gain
A-006-003-004
What is the primary purpose of an RF amplifier in a receiver?
(a) To improve the receiver noise figure
A-006-003-005
How is receiver sensitivity often expressed for UHF FM receivers?
(a) RF level for 12 dB SINAD
(b) RF level for a given Bit Error Rate (BER)
(c) Noise Figure in decibels
(d) Overall gain in decibels
A-006-003-005
How is receiver sensitivity often expressed for UHF FM receivers?
(a) RF level for 12 dB SINAD
A-006-003-006
What is the term used for the decibel difference (or ratio) between the largest tolerable receiver input signal (without causing audible distortion products) and the minimum discernible signal (sensitivity)?
(a) Dynamic range
(b) Design parameter
(c) Stability
(d) Noise figure
A-006-003-006
What is the term used for the decibel difference (or ratio) between the largest tolerable receiver input signal (without causing audible distortion products) and the minimum discernible signal (sensitivity)?
(a) Dynamic range
A-006-003-007
The lower the receiver noise figure becomes, the greater will be the receiver’s _________:
(a) rejection of unwanted signals
(b) sensitivity
(c) selectivity
(d) stability
A-006-003-007
The lower the receiver noise figure becomes, the greater will be the receiver’s _________:
(b) sensitivity
A-006-003-008
The noise generated in a receiver of good design originates in the:
(a) detector and AF amplifier
(b) BFO and detector
(c) IF amplifier and detector
(d) RF amplifier and mixer
A-006-003-008
The noise generated in a receiver of good design originates in the:
(d) RF amplifier and mixer
A-006-003-009
Why are very low noise figures relatively unimportant for a high frequency receiver?
(a) Ionospheric distortion of the received signal creates high noise levels
(b) The use of SSB and CW on the HF bands overcomes the noise
(c) External HF noise, man-made and natural, are higher than the internal noise generated by the receiver
(d) Regardless of the front end, the succeeding stages when used on HF are very noisy
A-006-003-009
Why are very low noise figures relatively unimportant for a high frequency receiver?
(c) External HF noise, man-made and natural, are higher than the internal noise generated by the receiver
A-006-003-010
The term which relates specifically to the amplitude levels of multiple signals that can be accommodated during reception is called:
(a) AGC
(b) cross-modulation index
(c) dynamic range
(d) noise figure
A-006-003-010
The term which relates specifically to the amplitude levels of multiple signals that can be accommodated during reception is called:
(c) dynamic range
A-006-003-011
Normally, front-end selectivity is provided by the resonant networks both before and after the RF stage in a superheterodyne receiver. This whole section of the receiver is often referred to as the:
(a) preselector
(b) preamble
(c) preamplifier
(d) pass-selector
A-006-003-011
Normally, front-end selectivity is provided by the resonant networks both before and after the RF stage in a superheterodyne receiver. This whole section of the receiver is often referred to as the:
(a) preselector
A-006-004-001
What audio shaping network is added at an FM receiver to restore proportionally attenuated lower audio frequencies?
(a) A pre-emphasis network
(b) An audio prescaler
(c) A de-emphasis network
(d) A heterodyne suppressor
A-006-004-001
What audio shaping network is added at an FM receiver to restore proportionally attenuated lower audio frequencies?
(c) A de-emphasis network
A-006-004-002
What does a product detector do?
(a) It provides local oscillations for input to a mixer
(b) It amplifies and narrows band-pass frequencies
(c) It mixes an incoming signal with a locally generated carrier
(d) It detects cross-modulation products
A-006-004-002
What does a product detector do?
(c) It mixes an incoming signal with a locally generated carrier
A-006-004-003
Distortion in a receiver that only affects strong signals usually indicates a defect in or mis-adjustment of the:
(a) IF amplifier
(b) AF amplifier
(c) automatic gain control (AGC)
(d) RF amplifier
A-006-004-003
Distortion in a receiver that only affects strong signals usually indicates a defect in or mis-adjustment of the:
(c) automatic gain control (AGC)
A-006-004-004
In a superheterodyne receiver with automatic gain control (AGC), as the strength of the signal increases, the AGC:
(a) reduces the receiver gain
(b) increases the receiver gain
(c) distorts the signal
(d) introduces limiting
A-006-004-004
In a superheterodyne receiver with automatic gain control (AGC), as the strength of the signal increases, the AGC:
(a) reduces the receiver gain
A-006-004-005
The amplified IF signal is applied to the ____________ stage in a superheterodyne receiver:
(a) RF amplifier
(b) audio output
(c) detector
(d) LO
A-006-004-005
The amplified IF signal is applied to the ____________ stage in a superheterodyne receiver:
(c) detector
A-006-004-006
The low-level output of a detector is:
(a) grounded via the chassis
(b) applied to the AF amplifier
(c) fed directly to the speaker
(d) applied to the RF amplifier
A-006-004-006
The low-level output of a detector is:
(b) applied to the AF amplifier
A-006-004-007
The overall output of an AM/CW/SSB receiver can be adjusted by means of manual controls on the receiver or by use of a circuit known as:
(a) automatic frequency control
(b) automatic gain control
(c) inverse gain control
(d) automatic load control
A-006-004-007
The overall output of an AM/CW/SSB receiver can be adjusted by means of manual controls on the receiver or by use of a circuit known as:
(b) automatic gain control
A-006-004-008
AGC voltage is applied to the:
(a) AF and IF amplifiers
(b) RF and AF amplifiers
(c) detector and AF amplifiers
(d) RF and IF amplifiers
A-006-004-008
AGC voltage is applied to the:
(d) RF and IF amplifiers
A-006-004-009
AGC is derived in a receiver from one of two circuits. Depending on the method used, it is called:
(a) RF derived or audio derived
(b) IF derived or RF derived
(c) IF derived or audio derived
(d) detector derived or audio derived
A-006-004-009
AGC is derived in a receiver from one of two circuits. Depending on the method used, it is called:
(c) IF derived or audio derived
A-006-004-010
Which two variables primarily determine the behaviour of an automatic gain control (AGC) loop?
(a) Blanking level and slope
(b) Slope and bandwidth
(c) Threshold and decay time
(d) Clipping level and hang time
A-006-004-010
Which two variables primarily determine the behaviour of an automatic gain control (AGC) loop?
(c) Threshold and decay time
A-006-004-011
What circuit combines signals from an IF amplifier stage and a beat-frequency oscillator (BFO), to produce an audio signal?
(a) A product detector circuit
(b) An AGC circuit
(c) A power supply circuit
(d) A VFO circuit
A-006-004-011
What circuit combines signals from an IF amplifier stage and a beat-frequency oscillator (BFO), to produce an audio signal?
(a) A product detector circuit
A-006-005-001
What part of a superheterodyne receiver determines the image rejection ratio of the receiver?
(a) Product detector
(b) RF amplifier pre-selector
(c) AGC loop
(d) IF filter
A-006-005-001
What part of a superheterodyne receiver determines the image rejection ratio of the receiver?
(b) RF amplifier pre-selector
A-006-005-002
What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?
(a) Cross-modulation interference
(b) Desensitization
(c) Squelch gain rollback
(d) Quieting
A-006-005-002
What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?
(b) Desensitization
A-006-005-003
What causes receiver desensitization?
(a) Squelch gain adjusted too high
(b) Squelch gain adjusted too low
(c) Strong near frequency signals
(d) Audio gain adjusted too low
A-006-005-003
What causes receiver desensitization?
(c) Strong near frequency signals
A-006-005-004
What is one way receiver desensitization can be reduced?
(a) Decrease the receiver squelch gain
(b) Increase the receiver bandwidth
(c) Use a cavity filter
(d) Increase the transmitter audio gain
A-006-005-004
What is one way receiver desensitization can be reduced?
(c) Use a cavity filter
A-006-005-005
What causes intermodulation in an electronic circuit?
(a) Too little gain
(b) Nonlinear circuits or devices
(c) Positive feedback
(d) Lack of neutralization
A-006-005-005
What causes intermodulation in an electronic circuit?
(b) Nonlinear circuits or devices
A-006-005-006
Which of the following is an important reason for using a VHF intermediate frequency in an HF receiver?
(a) To provide a greater tuning range
(b) To tune out cross-modulation distortion
(c) To move the image response far away from the filter passband
(d) To prevent the generation of spurious mixer products
A-006-005-006
Which of the following is an important reason for using a VHF intermediate frequency in an HF receiver?
(c) To move the image response far away from the filter passband
A-006-005-007
Intermodulation interference is produced by:
(a) the interaction of products from high-powered transmitters in the area
(b) the high-voltage stages in the final amplifier of an amplitude or frequency-modulated transmitter
(c) the mixing of more than one signal in the first or second intermediate frequency amplifiers of a receiver
(d) the mixing of two or more signals in the front-end of a superheterodyne receiver
A-006-005-007
Intermodulation interference is produced by:
(d) the mixing of two or more signals in the front-end of a superheterodyne receiver
A-006-005-008
Which of the following is NOT a direct cause of instability in a receiver?
(a) Mechanical rigidity
(b) Feedback components
(c) Temperature variations
(d) Dial display accuracy
A-006-005-008
Which of the following is NOT a direct cause of instability in a receiver?
(d) Dial display accuracy
A-006-005-009
Poor frequency stability in a receiver usually originates in the:
(a) detector
(b) local oscillator and power supply
(c) RF amplifier
(d) mixer
A-006-005-009
Poor frequency stability in a receiver usually originates in the:
(b) local oscillator and power supply
A-006-005-010
Poor dynamic range of a receiver can cause many problems when a strong signal appears within or near the front-end bandpass. Which of the following is NOT caused as a direct result?
(a) Desensitization
(b) Intermodulation
(c) Feedback
(d) Cross-modulation
A-006-005-010
Poor dynamic range of a receiver can cause many problems when a strong signal appears within or near the front-end bandpass. Which of the following is NOT caused as a direct result?
(c) Feedback
A-006-005-011
Which of these measurements is a good indicator of VHF receiver performance in an environment of strong out-of-band signals?
(a) Third-Order Intercept Point
(b) Two-tone Third-Order IMD Dynamic Range, 10 MHz spacing
(c) Blocking Dynamic Range
(d) Intermediate frequency rejection ratio
A-006-005-011
Which of these measurements is a good indicator of VHF receiver performance in an environment of strong out-of-band signals?
(b) Two-tone Third-Order IMD Dynamic Range, 10 MHz spacing
