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3-48. Which of the following methods is/are
used to determine the effectiveness of a tr
tube?
1. Measure the keep-alive current
2. Measure the keep-alive voltage
3. Graph the correlation between
recovery time and leakage power
4. All of the above
3-49. The presence of standing waves on a
transmission line indicates which of the
following conditions?
1. Excessive output power
2. An impedance mismatch
3. Excessive pulse width
4. Excessive prf
3-50. Of the following conditions, which
would be a likely indication of a high
vswr?
1. Insufficient reflection
2. Cold spots in the transmission line
3. Arc-over at the maximum points
4. All of the above
3-51. Most primary shipboard ac distribution
systems provide which of the following
types of electrical power?
1. 60 Hz, 3 phase, ungrounded
2. 60 Hz, 1 phase, ungrounded
3. 400 Hz, 1 phase, ungrounded
4. 400 Hz, 3 phase, ungrounded
3-52. If your equipment is missing a certain
voltage input, which of the following
actions should you take first?
1. Call an electrician
2. Energize the emergency generator
3. Check the input to the switchboard
4. Check the power panel that feeds
your equipment
3-53. What is the normal source of dry air for a
shipboard radar system?
1. Compressed-air bottles
2. Central dry-air system
3. Dehumidifying ovens
4. Local dehydrators
3-54. The air control panel is designed to
regulate
1. flow
2. purity
3. pressure
4. dew point
3-55. Which of the following units may be
available as an emergency back-up to the
central dry-air system?
1. Nitrogen tank
2. Local dehydrator
3. Local compressor-dehydrator
4. Each of the above
3-56. Which of the following methods is used
to cool radar system components?
1. Air blowers
2. Liquid-cooling loops
3. Air-conditioning systems
4. Each of the above
3-57. A radar cooling system has a low-flow
alarm in the sea-water loop. What is the
primary purpose of this alarm?
1. It allows correction before damage
occurs
2. It increases the flow in the distilled-
water loop
3. It removes power from the system
4. It increases the sea-water pressure
