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 321 of 590

6-11

TM 9-1240-401-34&P

I

b. INSTALLING M42 PERISCOPE ON INSPECTION FIXTURE

1 Mount M42 periscope (1) on inspection fixture (2),

making sure that all mating surfaces are free of

dirt, burrs, and other defects which would interfere

with proper seating.

2 Secure M42 periscope (1) to inspection fixture (2)

using three screws (3).

I

C. IMAGE TILT ADJUSTMENT

1

2

3

4

5

6

Check collimation by viewing reticle images

through auxiliary telescope (1). Image of auxiliary

telescope (1) reticle intersection point should coin-

cide with reticle image of collimating projector (2).

If auxiliary telescope (1) reticle does not coincide

with image of collimating projector (2) reticle, ad-

just cover assembly (3) by turning three setscrews

(4).

Check image tilt by viewing image of collimating

projector vertical reticle line through auxiliary tele-

scope (1). Vertical reticle line image should be ver-

tical within 1 degree as measured on auxiliary tele-

scope reticle (ref. TM 9-254).

If image tilt is not within specified limits, adjust the

cover assembly (3) by turning three setscrews (4).

Recheck collimation (step 1) and adjust as neces-

sary (step 2).

Apply adhesive to three setscrews (4) after final

adjustment.