TM 5-6675-250-10
1-9. TECHNICAL PRINCIPLES OF OPERATION - Continued
Brake on indicator (6). Illuminates when the MODE SELCT switch is placed to BRAKE ON,
(6)
indicating the braking sequence. At the completion of the sequence, a 90-second dynamic
braking of the gyro motor, the BRAKE ON indicator light will be extinguished.
Thoedolite brightness control (7). Rotating the control clockwise increases the intensity
(7)
of the light.
Reset switch (8). Enables the operator to reinitiate the gyrocompass interval. Pressing the
(8)
RESET switch extinguishes the READ AZIMUTH indicator and reinitiates gyrocompass
action for a minimum of 45 seconds.
Bias control (9). Following self-test operations, the instrument is adjusted for bias through
(9)
the BIAS control. Rotating the BIAS control clockwise will move the pointer to the right, and
counterclockwise rotation will move the pointer to the left. Careful attention should be giv-
en to positioning the pointer in the center of the scale to ensure the highest degree of accu-
racy.
(10) Bias lock (10). Mechanically holds the BIAS CONTROL in the set position to prevent an
accidental movement.
(11) Read azimuth indicator (11). Illuminates when true north has been obtained; light is
applied automatically to the theodolite scale for azimuth reading.
(12) Gyro sync indicator (12). Illumination indicates that the gyro motor has attained synchron-
ous speed. When the GYRO SYNC indicator illuminates the CAGE-U NCAGE knob, the GRU is
to be rotated to UNCAGE (clockwise rotation).
(13) Latitude select switch (13). Provided to maintain instrument operating time at different lat-
itudes of operation. The switch is adjustable with a screwdriver and contains eight posi-
tions. The switch positions and corresponding latitudes of operation areas follows:
Latitude of Operation
Switch Position
0-15 degrees
0
15-30 degrees
25
30-45 degrees
40
45-55 degrees
50
55-63 degrees
60
63-67 degrees
65
67-73 degrees
70
73-75 degrees
75
1-17
Previous Page
