Topic G7C Quick Review Audio


Which of the following is used to process signals from the balanced modulator then send them to the mixer in some single sideband phone transmitters?

  1. Carrier oscillator
  2. Filter
  3. IF amplifier
  4. RF amplifier


Which circuit is used to combine signals from the carrier oscillator and speech amplifier then send the result to the filter in some single sideband phone transmitters?

  1. Discriminator
  2. Detector
  3. IF amplifier
  4. Balanced modulator


What circuit is used to process signals from the RF amplifier and local oscillator then send the result to the IF filter in a superheterodyne receiver?

  1. Balanced modulator
  2. IF amplifier
  3. Mixer
  4. Detector


What circuit is used to combine signals from the IF amplifier and BFO and send the result to the AF amplifier in some single sideband receivers?

  1. RF oscillator
  2. IF filter
  3. Balanced modulator
  4. Product detector


Which of the following is an advantage of a direct digital synthesizer (DDS)?

  1. Wide tuning range and no need for band switching
  2. Relatively high-power output
  3. Relatively low power consumption
  4. Variable frequency with the stability of a crystal oscillator


What should be the impedance of a low-pass filter as compared to the impedance of the transmission line into which it is inserted?

  1. Substantially higher
  2. About the same
  3. Substantially lower
  4. Twice the transmission line impedance


What is the simplest combination of stages that implement a superheterodyne receiver?

  1. RF amplifier, detector, audio amplifier
  2. RF amplifier, mixer, IF discriminator
  3. HF oscillator, mixer, detector
  4. HF oscillator, prescaler, audio amplifier


What circuit is used in analog FM receivers to convert IF output signals to audio?

  1. Product detector
  2. Phase inverter
  3. Mixer
  4. Discriminator


What is the phase difference between the I and Q signals that software-defined radio (SDR) equipment uses for modulation and demodulation?

  1. Zero
  2. 90 degrees
  3. 180 degrees
  4. 45 degrees


What is an advantage of using I and Q signals in software-defined radios (SDRs)?

  1. The need for high resolution analog-to-digital converters is eliminated
  2. All types of modulation can be created with appropriate processing
  3. Minimum detectible signal level is reduced
  4. Converting the signal from digital to analog creates mixing products


What is meant by the term "software-defined radio" (SDR)?

  1. A radio in which most major signal processing functions are performed by software
  2. A radio that provides computer interface for automatic logging of band and frequency
  3. A radio that uses crystal filters designed using software
  4. A computer model that can simulate performance of a radio to aid in the design process


What is the frequency above which a low-pass filter's output power is less than half the input power?

  1. Notch frequency
  2. Neper frequency
  3. Cutoff frequency
  4. Rolloff frequency


What term specifies a filter's maximum ability to reject signals outside its passband?

  1. Notch depth
  2. Rolloff
  3. Insertion loss
  4. Ultimate rejection


The bandwidth of a band-pass filter is measured between what two frequencies?

  1. Upper and lower half-power
  2. Cutoff and rolloff
  3. Pole and zero
  4. Image and harmonic


What term specifies a filter's attenuation inside its passband?

  1. Insertion loss
  2. Return loss
  3. Q
  4. Ultimate rejection


Which of the following is a typical application for a Direct Digital Synthesizer?

  1. A high-stability variable frequency oscillator in a transceiver
  2. A digital voltmeter
  3. A digital mode interface between a computer and a transceiver
  4. A high-sensitivity radio direction finder