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 227 of 590

TM 9-1240-401-34&P

5-53

f. IMAGE TILT ADJUSTMENT

1

2

3

4

5

6

7

8

9

Position pre-plumbed collimating projector (1) at

level of window in cap (2) of M117/M117A2 pano-

ramic telescope so that the two optical axes lie in

parallel planes.

Check image tilt through one full revolution of the

cap (2) in each direction. The image of the vertical

reticle line shall be vertical within 2° (0.62 mils) of

arc. This requirement shall also be met with the

elbow assembly positioned against each of the

swing stops at each azimuth setting.

If image tilt is not within specified limits, remove

three machine screws (3) and access cover (4).

Remove setscrew (5) from shaft (6).

Insert hexagon key into center of shaft (6) and turn

until image of the vertical reticle line is within 2°

(0.62 mils) of arc. (Ref. TM 9-254 for conversion to

roils.)

Remove hexagon key and replace setscrew (5). Be

careful not to disturb established position.

Recheck image tilt as directed in steps 1 and 2.

If necessary, repeat steps 4,5, and 6.

Install access cover (4) and secure with three

machine screws (3).