Topic G8B Quick Review Audio


Which mixer input is varied or tuned to convert signals of different frequencies to an intermediate frequency (IF)?

  1. Image frequency
  2. Local oscillator
  3. RF input
  4. Beat frequency oscillator


If a receiver mixes a 13.800 MHz VFO with a 14.255 MHz received signal to produce a 455 kHz intermediate frequency (IF) signal, what type of interference will a 13.345 MHz signal produce in the receiver?

  1. Quadrature noise
  2. Image response
  3. Mixer interference
  4. Intermediate interference


What is another term for the mixing of two RF signals?

  1. Heterodyning
  2. Synthesizing
  3. Cancellation
  4. Phase inverting


What is the stage in a VHF FM transmitter that generates a harmonic of a lower frequency signal to reach the desired operating frequency?

  1. Mixer
  2. Reactance modulator
  3. Pre-emphasis network
  4. Multiplier


What is the approximate bandwidth of a PACTOR-III signal at maximum data rate?

  1. 31.5 Hz
  2. 500 Hz
  3. 1800 Hz
  4. 2300 Hz


What is the total bandwidth of an FM phone transmission having 5 kHz deviation and 3 kHz modulating frequency?

  1. 3 kHz
  2. 5 kHz
  3. 8 kHz
  4. 16 kHz


What is the frequency deviation for a 12.21 MHz reactance modulated oscillator in a 5 kHz deviation, 146.52 MHz FM phone transmitter?

  1. 101.75 Hz
  2. 416.7 Hz
  3. 5 kHz
  4. 60 kHz


Why is it important to know the duty cycle of the mode you are using when transmitting?

  1. To aid in tuning your transmitter
  2. Some modes have high duty cycles that could exceed the transmitter's average power rating
  3. To allow time for the other station to break in during a transmission
  4. The attenuator will have to be adjusted accordingly


Why is it good to match receiver bandwidth to the bandwidth of the operating mode?

  1. It is required by FCC rules
  2. It minimizes power consumption in the receiver
  3. It improves impedance matching of the antenna
  4. It results in the best signal-to-noise ratio


What is the relationship between transmitted symbol rate and bandwidth?

  1. Symbol rate and bandwidth are not related
  2. Higher symbol rates require wider bandwidth
  3. Lower symbol rates require wider bandwidth
  4. Bandwidth is always half the symbol rate


What combination of a mixer's Local Oscillator (LO) and RF input frequencies is found in the output?

  1. The ratio
  2. The average
  3. The sum and difference
  4. The arithmetic product


What process combines two signals in a non-linear circuit or connection to produce unwanted spurious outputs?

  1. Intermodulation
  2. Heterodyning
  3. Detection
  4. Rolloff