TM-9-1240-401-34-P

TELESCOPE MOUNT M146: M118A2 AND M118A3; TELESCOPE MOUNT M145: M145A1; PANORAMIC TELESCOPE: M117 AND M117A2; FIRE CONTROL QUADRANT: M15; PERISCOPE: M42

TECHNICAL MANUAL; DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE MANUAL

JULY 1993

TM-9-1240-401-34-P - Page 241 of 590

TM 9-1240-401-34&P

Item No.

4

5

Item To Be Inspected

ELEVATION KNOB (4) AND

ELEVATION MECHANISM -

CONTINUED

CROSS-LEVEL KNOB (5) AND

CROSS LEVEL MECHANISM

Procedures

b.

c.

a.

b.

c.

Check elevation travel by turning elevation knob clockwise to

stop. Center elevation level vial bubble by turning handwheel on

upper section of cross-leveling fixture. Check that scale on upper

section of cross-leveling fixture reads at least 77° 47’ 37.5”. Turn

elevation knob counterclockwise to stop and center elevation level

vial bubble. Check that upper scale reads at least 12° 49’ 30”.

Check backlash by turning elevation knob clockwise to center

elevation level vial bubble. Turn counterclockwise past center

and then back to original position. Check that level vial bubble

centers again within 1/2 space between level vial graduations.

Check that torque required to turn elevation knob in either

direction does not exceed 8 pound-inches (0.904 N-m) at any

point between stops.

Check cross-level travel by turning cross-level knob to either stop.

Turn handwheel on lower section of cross-leveling fixture to center

cross-level vial bubble. Check that scale on lower section of

cross-leveling fixture reads at least 34°.

With cross-level vial bubble centered, turn cross-level knob

clockwise. Then turn back to original position to check backlash.

Check that cross-level vial bubble centers within 1/2 space

between level vial graduations.

Change 1

5.1-7