RMHS REFERENCE GYRO SET SHUT-DOWN PROCEDURES.

TM 55-6605-263-14&P

o. Positive Gyro Drift Correction. If compass has positive drift rate indicated by increase in degrees/minutes, lower

voltage by 0.5 volts on built-in voltmeter. Observe indication for six minutes. Multiply drift rate, minutes by 10, to

ascertain drift rate per hour. Continued voltage adjustment will produce a desired drift rate.

p. Negative Gyro Drift Correction. If compass has negative drift rate indicated by a decrease in degrees/minutes,

increase voltage by 0.5 volts.

NOTE

If bias adjust reaches full travel and more voltage compensation is required, return bias adjust to indicate

6 volts and turn latitude dial clockwise to correct negative drift and counterclockwise to correct positive

drift. When drift is close to that desired, use bias adjust to finalize drift adjustment. The acceptable drift

rate can be obtained in one hour.

q. Place Angle Position Indicator so that both the water-craft operator and compass adjuster can view the indicator

headings.

r. Perform a 360 degrees compass swing while making adjustments to the watercraft compass under test.

s. After redocking, compare the present heading of the RMHS Reference Gyro Set to the original heading. See

paragraph k. And determine drift.

NOTE

If Gyro drift rate is more than two degrees, recalibration of the Gyro drift voltage is required.

Recheck watercraft compass adjustments.

2-9.

RMHS REFERENCE GYRO SET SHUT-DOWN PROCEDURES.

a. Set control panel ON-OFF-POLARITY switch to OFF.

b. Set ON-OFF switch in Angle Position Indicator to OFF.

c. Remove dc power leads from external 28 volt source.

d. Remove indicator cable from Angle Position Indicator and secure cable and Angle Position Indicator in case.

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