TM-9-1240-401-34&P Technical Manual for M109 Telescopes and Mounts Download
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4-50 TM 9-1240-401-34&P 4-24. M145/M145A1 TELESCOPE MOUNT FINAL INSPECTION AND ADJUSTMENT - continued a. SETTING UP AND ADJUSTING THE CROSS-LEVELING FIXTURE - continued 10 11 12 13 14 Mount setup gage (10) on fixture adapter (6), and secure with four mounting bolts (11). Install collimating telescope (12) in setup gage (10). Snug up thumbscrews (13) securing collimating telescope (12); do not tighten at this time. Suspend a plumb line approximately 25 feet (7.62m) directly in front of collimating telescope (12). Revolve collimating telescope (12) until its vertical line is superimposed on plumb line. Tighten thumb- screws (13) holding collimating telescope (12). Fabricate rigidity test target (14). Use the following formula for target fabrication of test target: TARGET DISTANCE 1 MIL GRADUATION = (IN INCHES) 1000 GIVEN: TARGET DISTANCE = DISTANCE FROM SIGHTING DEVICE TO PLACEMENT OF TARGET. EXAMPLE: 1 MIL = 50 FT x 12 IN/FT = 0.6 IN GRADUATION 1000 0.25 MIL = 0.6 IN X 0.25 = 0.15 IN 1.50 MIL = 0.6 IN X 1.50 = 0.9 IN