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 158 of 590

TM 9-1240-401-34&P

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

- continued

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c. Assembly - continued

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25

26

27

28

29

30

31

NOTE

If the counter box assembly has a tapped hole

to screw purging valve stem into, nut (7) is not

required.

Apply sealing compound to threads of nut (7) and

purging valve stem (10).

Install retaining strap (11), purging valve stem (10),

nut (7), valve core (9), and air valve cap (8).

If removed, install plug (6).

If removed, install two headless straight pins (5).

Install cover (3) with related parts on counter box

assembly (4) and secure with four new lock-

washers (2) and four machine screws (1).

Install elevation handwheel (38) (ref. para 4-17).

Using elevation handwheel (38), set correction

counter (39) to 0000. Rotate elevation handwheel

(38) counterclockwise and ensure correction

counter (39) attains a minimum reading of 1335

roils.

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