1-47. 1-48. 1-49. 1-50. 1-51. 1-52. To produce a video pulse of sufficient amplitude to intensify the beam of a CRT, what voltage amplification  is  required? 1.   l/10th 2.  3/10th 3.  5/10th 4.   10/10th After the echo signal enters the system through the antenna, what is the next section it passes through? 1.   Duplexer 2.  Modulator 3.   Amplifier 4.  Cathode-ray  tube What is normally used to keep the receiver in tune with the transmitter? 1. 2. 3. 4. Difference frequency system Backward-wave  oscillator Frequency  synthesizer Local oscillator In receivers that use crystal mixers, the power required to operate the local oscillator is 1.  large 2.   small 3.  negative 4.  positive Reflex klystrons can also be used in RF power amplifier klystrons as 1.   pulse-forming   networks 2.   modulators 3.   drivers 4.   tuners What system is taking the place of the STALO in radar systems? 1. 2. 3. 4. Local oscillator Frequency synthesizer Backward-wave  oscillator Automatic frequency control 1-53. What is the simplest type of radar mixer? 1.  Magic   T 2.  Hybrid 3.   Balanced 4.  Unbalanced  crystal 1-54, 1-55. 1-56. 1-57. 1-58. What is the major disadvantage of the unbalanced crystal mixer? 1.  Inability  to  cancel  LO  noise 2.  Inability  to  synthesize  LO  noise 3. Inability to produce LO noise 4.  Inability  to  modulate  LO  noise Which of the following factors is NOT determined by the IF section of a radar receiver? 1.  Signal-to-noise  ratio 2.  Effective  bandwidth 3.  Receiver  gain 4.   Pulsewidth What is used to control the gain of a radar receiver as a function of range? 1.   MTI 2.   STC 3.   AGC 4.   STALO In what type of receivers are logarithmic IF amplifiers used? 1.  F M 2.  AM 3.   Heterodyne 4.  Electronic  attack The detector in a basic radar receiver converts which of the following signals into a video signal? 1.  RF 2.   IF 3.  LO 4.   MTI 5