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 156 of 590

TM 9-1240-401-34&P

4-21. COUNTER BOX ASSEMBLY (COUNTERS) MAINTENANCE INSTRUCTIONS

- continued

c. Assembly - continued

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Install correction knob (35) (ref. para 4-17).

NOTE

Perform steps 6 thru 12 if new elevation rotat

ing counter is installed. If reinstalling existing

elevation rotating counter (29), go to step 13.

Temporarily install a setscrew in gear (33) and

slide gear (33) onto shaft of elevation rotating

counter (29).

Secure elevation rotating counter (29) to base (36)

using four new Iockwashers (28) and four machine

screws (27).

Drill two pilot holes approximately 1/16 inch (0.16

mm) deep into base of elevation rotating counter

(29), ensuring that drill bit does not damage numer-

als or elevation rotating counter (29) shaft.

Remove elevation rotating counter (29) from base

(36) and finish drilling holes in elevation rotating

counter (29).

Drill, ream, and pin gear (33) to shaft of elevation

rotating counter (29) using tapered pin (32).

Install mask (31) on elevation rotating counter (29)

and secure with two machine screws (30).

Install two headless straight pins (34), into base

(36).

Rotate correction knob (35) counterclockwise to

stop.

Set elevation rotating counter (29) to an indication

of -50.

Install elevation rotating counter (29) on base (36)

and secure with four new lockwashers (28) and

four machine screws (27).

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