A-006 — Receivers

Receivers: superheterodyne design, selectivity, sensitivity, images, AGC and noise.

All 55 questions

• A-006-001-001 What are the advantages of the frequency conversion process in a superheterodyne receiver?
• A-006-001-002 What factors should be considered when selecting an intermediate frequency?
• A-006-001-003 One of the greatest advantages of the double-conversion over the single-conversion receiver is that it:
• A-006-001-004 In a communications receiver, a crystal filter would be located in the:
• A-006-001-005 A multiple conversion superheterodyne receiver is more susceptible to spurious responses than a single-conversion receiver because of the:
• A-006-001-006 In a dual-conversion superheterodyne receiver what are the respective aims of the first and second conversion:
• A-006-001-007 Which stage of a receiver has its input and output circuits tuned to the received frequency?
• A-006-001-008 Which stage of a superheterodyne receiver lies between a tuneable stage and a fixed tuned stage?
• 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-006-001-010 A double conversion receiver designed for SSB reception has a beat frequency oscillator and:
• A-006-001-011 The advantage of a double conversion receiver over a single conversion receiver is that it:
• A-006-002-001 The mixer stage of a superheterodyne receiver is used to:
• A-006-002-002 A superheterodyne receiver designed for SSB reception must have a beat-frequency oscillator (BFO) because:
• A-006-002-003 The first mixer in the receiver mixes the incoming signal with the local oscillator to produce:
• 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-006-002-005 The BFO is off-set slightly (500 - 1 500 Hz) from the incoming signal to the detector. This is required:
• A-006-002-006 It is very important that the oscillators contained in a superheterodyne receiver are:
• 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-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-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-006-002-010 Which two stages in a superheterodyne receiver have input tuned circuits tuned to the same frequency?
• A-006-002-011 The mixer stage of a superheterodyne receiver:
• A-006-003-001 What is meant by the noise floor of a receiver?
• A-006-003-002 Which of the following is a purpose of the first IF amplifier stage in a receiver?
• A-006-003-003 How much gain should be used in the RF amplifier stage of a receiver?
• A-006-003-004 What is the primary purpose of an RF amplifier in a receiver?
• A-006-003-005 How is receiver sensitivity often expressed for UHF FM receivers?
• 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-006-003-007 The lower the receiver noise figure becomes, the greater will be the receiver's _________:
• A-006-003-008 The noise generated in a receiver of good design originates in the:
• A-006-003-009 Why are very low noise figures relatively unimportant for a high frequency 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-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-006-004-001 What audio shaping network is added at an FM receiver to restore proportionally attenuated lower audio frequencies?
• A-006-004-002 What does a product detector do?
• A-006-004-003 Distortion in a receiver that only affects strong signals usually indicates a defect in or mis-adjustment of the:
• A-006-004-004 In a superheterodyne receiver with automatic gain control (AGC), as the strength of the signal increases, the AGC:
• A-006-004-005 The amplified IF signal is applied to the ____________ stage in a superheterodyne receiver:
• A-006-004-006 The low-level output of a detector is:
• 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-006-004-008 AGC voltage is applied to the:
• A-006-004-009 AGC is derived in a receiver from one of two circuits. Depending on the method used, it is called:
• A-006-004-010 Which two variables primarily determine the behaviour of an automatic gain control (AGC) loop?
• 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-006-005-001 What part of a superheterodyne receiver determines the image rejection ratio of the receiver?
• A-006-005-002 What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?
• A-006-005-003 What causes receiver desensitization?
• A-006-005-004 What is one way receiver desensitization can be reduced?
• A-006-005-005 What causes intermodulation in an electronic circuit?
• A-006-005-006 Which of the following is an important reason for using a VHF intermediate frequency in an HF receiver?
• A-006-005-007 Intermodulation interference is produced by:
• A-006-005-008 Which of the following is NOT a direct cause of instability in a receiver?
• A-006-005-009 Poor frequency stability in a receiver usually originates in the:
• 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-006-005-011 Which of these measurements is a good indicator of VHF receiver performance in an environment of strong out-of-band signals?