OPERATING PROCEDURES

TM 55-6605-263-14&P

f. Set ON-OFF-POLARITY switch to OFF.

NOTE

Start watercraft engines to set-up normal hull vibrations and stabilize external 28 Vdc source. Leave

watercraft engines running until compass adjustments are completed.

g. Set ON-OFF-POLARITY switch to ON. Power lamp (red) will illuminate.

h. Set power ON-OFF switch at Angle Position Indicator to ON.

Set Gyro latitude switch to either "N" or "S" depending on which hemisphere watercraft is located.

j. Set latitude dial on Gyro to indicate watercraft's local latitude.

k. Obtain the watercraft's heading via navigational charts, dock placement headings or other known accurate

heading sources.

NOTE

Allow a Gyro warm-up period of 30 minutes to reach full speed and to stabilize.

l. Rotate the RMHS Reference Gyro Set in the case, by loosening the four clamp screws, until the Angle Position

Indicator reading reflects watercraft heading.

m. Set the drift bias adjustment potentiometer until the control panel dc voltmeter indicates +6 Vdc.

n. Check Angle Position Indicator reading to determine direction of any drift (drift in excess of two degrees/four

hours must be corrected).

NOTE

Establishing drift rate is preferred at a pier with known accurate heading, holding vessel tight against

pier. Once drift is stabilized at pier, move vessel into channel and swing for 30 minutes. Come back to

pier and check drift. Make drift corrections. Significant drift is only encountered while vessel is swinging.

Each time vessel is returned to pier during RMHS calibration, drift rate should be checked.

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