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 226 of 590

TM 9-1240-401-34&P

5-26. M117/M117A2 PANORAMIC TELESCOPE FINAL INSPECTION AND ADJUSTMENT

- continued

d. EYEPIECE FOCUS

1 Using dioptometer (1), check reticle focus for the

optimum focus of minus 0.5 to minus 1.0 diopter.

2 If adjustment is required, remove four setscrews

(2) and rotate M117/M117A2 panoramic telescope

eyepiece (3) until optimum focus is achieved.

3

4

Using hand sealing gun, inject sealing compound

into holes of two setscrews (2) nearest to counter

assembly.

Apply sealing compound to threads of four

setscrews (2) and install.

e. PARALLAX ADJUSTMENT

1

2

3

Sighting through M117/M117A2 panoramic tele-

scope eyepiece (1), adjust M117/M117A2 pano-

ramic telescope until reticle geometric center (inter-

section of cross lines) is on the vertical line of test

reticle of the collimating projector (2).

Move head from side to side while viewing through

M117/M117A2 panoramic telescope eyepiece (1).

Parallax (movement between collimating projector

(2) reticle and the M117/M117A2 panoramic tele-

scope reticle) must not exceed thickness of vertical

reticle line (0.1 mil).

If parallax is not within specified limits, return

M117/M117A2 panoramic telescope to depot main-

tenance.

5-52