14
2-54. An overdriven amplifier stage in a
receiver may cause which of the
following conditions?
1. Blocking
2. Inaccurate ranges
3. Increased sensitivity
4. Large signal distortion
2-55. The intermediate frequency is produced
in what stage of a microwave receiver?
1. The mixer
2. The IF amplifier
3. The second detector
4. The local oscillator
2-56. What section of a radar receiver usually
determines the overall bandwidth?
1. The mixer
2. The IF amplifier
3. The video amplifier
4. The local oscillator
2-57. What component in a receiver afc circuit
produces an output voltage proportional
in amplitude and polarity to any change
in the intermediate frequency?
1. The mixer
2. The IF amplifier
3. The discriminator
4. The local oscillator
2-58. An efficient local oscillator must have
which of the following characteristics?
1. Tunable frequency
2. Stable output frequency
3. Operation in the 4,000 megahertz
range
4. All of the above
2-59. Which of the following devices would be
used as a local oscillator in a radar
receiver?
1. A magnetron
2. A crystal diode
3. A reflex klystron
4. A parametric amplifier
2-60. Which of the following advantages is
gained by using a crystal mixer in a
microwave receiver?
1. Less noise
2. Reduced saturation
3. Increased overall gain
4. Improved oscillator stability
2-61. The resonant circuit at the output of an
unbalanced crystal mixer serves which of
the following purposes?
1. It amplifies the IF signal
2. It produces the IF signal
3. It eliminates unwanted signals
4. It amplifies the local oscillator signal
2-62. The balanced transformer connected to
the crystals of a balanced mixer has a
secondary that is tuned to what
frequency?
1. The desired IF
2. The local oscillator frequency
3. The afc discriminator frequency
4. The transmitter carrier frequency
2-63. The IF amplifier stage of a radar receiver
determines which of the following
receiver characteristics?
1. The gain
2. The effective bandwidth
3. The signal-to-noise ratio
4. All of the above
