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46 Cards in this Set
- Front
- Back
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What indicator indicates the gyro is ready to receive a latitude entry? |
When the ENTER LAT switch-indicator is on. |
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What is used to excite the roll, pitch & heading located in the IMU gimbal, when the gimbal is caged? |
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What is the approximate time the battery will provide a nomonal 24V output? |
30 min |
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What occurs with the MODE switch in the NAV MODE? |
Primary operating mode; eqpt. becomes a north-pointing gyrocompass |
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When is digital coarse leveling complete and fine leveling started? |
absolute values of velocity error signal represent less than .5 ft/sec & 60 secs have elapsed. |
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What is the composition of the AN/WSN battery set? |
60 sealed lead-acid storage cells connected in series-parallel branches, consisting of 12 cells per branch. |
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What is meant by plane of rotation? |
Direction that the axle is aligned or pointed |
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What is the effect of the Earth's rotation on the gyroscope axle? |
North end rises when East of the meridian & falls when West of the meridian in any latitude. |
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What is supported by the spider? |
Phantom Gyrosphere Vertical Ring assembly |
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What is the 2nd degree of freedom for the inner gimbal? |
Free to rotate about the horizontal or Y axle |
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Why is the precession about the horizontal axis much slower than precession about the vertical axis? |
Point of connection offset from vertical axis only a small amount |
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What's the result when weight & buoyancy of the gyro are properly adjusted in the oil? |
No load placed on vertical pivots Vertical bearings serve only as guides for the sphere. |
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When does the rotor of a gyro have on plane of rotation? |
As long as its axle is aligned with, or pointed at, one point in space. |
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How are the azimuth control torquers physically mounted? |
Diametrically opposite each other on the adapter ring and they'r electrically connected together to reproduce torque. |
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What is used in place of weights on the mechanical gyrocompass? |
Gravity reference system |
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What is the 1st step in changing the gyroscope to a gyrocompass? |
Make a change in the suspension system |
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What system drives thee phantom bowl in azimuth so that the vertical ring is continuously aligned with the plane of the gyro? |
Follow up system |
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What are the separate systems of the compass control system? |
Gravity reference Azimuth control Leveling control |
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What is the damping factor for both pendulous and nonpendulous type compasses? |
About 70% |
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How does operation of MK19 compare to MK23? |
2 Gyro elements, meridian & slave, with their planes of rotation displaced by 90 degrees |
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What is the initial step in lighting off MK19? |
Mode selector switch to FAST SETTLE Turn master switch to FIL and wait about a minute to allow filaments to heat |
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What would someone see in space below the South Pole, if a free-spinning gyroscope is placed on the Earth's surface at the equator, with its spinning axis horizontal and aligned East & West? |
The Earth rotates clockwise from West to East and carries the gyroscope along. |
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What is the spider element? |
Case member having 2 ribbed arms carrying pivots which fit in bearing on the gimbal ring. |
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What is the 1st degree of freedom for a rotor? |
Free to spin on its own axle, or X axle |
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What is the approximate rotor speed of the gyrosphere? |
23,600 rpm **direction is clockwise when viewed from the south end** |
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What's the next step after the MK19 is aligned with ship's heading during light off process? |
Wait 11 min or until blue READY lamp lights, to ensure gyro is still aligned in azimuth & slew it to ship's heading again if necessary. |
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What actions are taken if power to the compass fails? |
Place power switch in FIL position & operation switch in CAGE position. When power's restored, restart the compass in the usual manner |
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What is the phantom element? |
Bowl-shaped casting supported on ball bearings, located within the spider, & rotates about the vertical axis of the gyrosphere. |
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What mounts the azimuth gear and slip rings? |
The phantom element |
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What modification must be made for a gyro to become a gyrocompass? |
1. Align its axis on the meridian 2. Align its axis nearly horizontal 3. Maintain its alignment both horizontal on the meridian, once it is attained. |
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What's the result of the leveling control system? |
system causes a torque about the gyro's vertical axis, causing it to assume a level position. |
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What is the division for all controls of the MK gyrocompass system? |
1.Compass control system 2.Follow-up system |
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When should the MK23 be started before its needed for service? |
At least 2 hours before |
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What's the simplest method of accomplishing the damping in older gyrocompasses? |
Pendulous & Nonpendulous method |
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What causes the tilt when the gyro is started while pointed away from the meridian? |
Effect of the Earth rate |
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What's the term for the average amount by which successive oscillations are reduced? |
Percentage of damping or the damping factor |
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What is contained in the electrolytic level of the gravity reference system? |
Cylindrical glass vial with 3 platinum electrodes |
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what determines the period of oscillation in a gyrocompass? |
Speed and weight of rotor & Weight of the pendulous weight |
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When does the watchstander make entries in the daily gyro log sheet? |
Each hour |
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Whose permission is needed to use FAST SETTLE when the gyro is started in NORMAL MODE? |
CHENG |
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What is the 1st step in changing the gyroscope to a gyrocompass? |
Change in the suspension system |
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What is meant by the plane of rotation? |
Direction that the axle is aligned or pointed |
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How does the damping action occur in the pendulous method if the North end of the gyroscope axle is elevated? |
Pendulous weight exerts downward force on high, or North, axle. At the same time, oil begins to flow N tank to S tank or exert small force on low, South, end. |
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What is the composition of the master unit? |
1. Shock-mounted, oil-filled binnacle 2. Gyrocompass element |
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Why will there be no apparent tilt of the gyro axle if a ship's course is East-West? |
Ship's course is parallel to the plane of the gyro |
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what loads the horizontal bearings? |
Only the weight of the vertical ring & its components, which are also reduced in weight due to partial flotation. |
