TM-9-1240-401-34&P Technical Manual for M109 Telescopes and Mounts Download
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3-50 TM 9-1240-401-34&P 3-29. M118A2/M118A3 ELBOW TELESCOPE FINAL INSPECTION AND ADJUSTMENT - continued c. PARALLAX ADJUSTMENT 1 2 3 4 5 6 View through M118A2/M118A3 elbow telescope eyepiece (1) and move head from side to side. Ap- parent movement between telescope reticle crosslines and target image should not exceed 0.15 mil (the width of reticle line) as measured on collimating projector (2) reticle. If error exists, remove setscrew (3). Using 2 and 2-1/64 inch tubular spanner wrench (Item 33, appx F), remove cell assembly (4). Using 1-7/16 and 1-29/64 inch tubular spanner wrench (Item 30, appx F), make adjustment to cell (5) by rotating cell (5) until reticle crosslines are parallel. Install cell assembly (4) using 2 and 2-1/64 inch tubular spanner wrench (Item 33, appx F). Install setscrew (3). d. EYEPIECE FOCUS ADJUSTMENT 1 2 3 4 5 6 7 8 Rotate eyepiece of dioptometer (1) until reticle lines of dioptometer are in sharp focus. Place dioptometer (1) in front of M118A2/M118A3 elbow telescope eyepiece (2). Look through dioptometer (1) and slide dioptometer objective back and forth until M118A2/M118A3 el- bow telescope reticle lines appear sharp and clear. Remove dioptometer (1), without disturbing its set- ting, and note reading on side of dioptometer. Eye- piece focus, as indicated on dioptometer (1), should be-0.75 to-1.0 diopter. If error exists, remove setscrews (3 and 4) from eyepiece arm. Make adjustment to cell assembly through hole where larger setscrew (4) was removed. Recheck eyepiece focus. Install setscrews (3 and 4). Do not overtighten.