TM-9-1240-400-34&P Technical Manual for M109 Telescopes and Mounts Download
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TM 9-1240-400-34&P 2-5. CATEGORIES OF INSPECTION (CONT). Table 2-1. INITIAL INSPECTION-M115 PANORAMIC TELESCOPE (CONT) ITEM ITEM T0 NO. BE INSPECTED PROCEDURE -- Lift (Deflection) During level travel test, direction of head rotation shall be reversed. Any vertical displacement of line of sight with respect to horizontal target line resulting from this reversing of travel shall not exceed 0.5 mil. This test shall be performed at minimum of eight 800-mil deflection (azimuth) settings. -- Backlash This test should be conducted at same time as level travel test. While rotating deflection knob, backlash in deflection counter must not exceed 1.0 mil, and backlash in reset counter must not exceed 1.25 mil. -- Open Sight While viewing a calibrated wall target positioned 50 ft (15 m) from objective end of telescope, line of sight through boresight mark of telescope reticle shall be horizontal and parallel in deflection, with respect to line of sight of open sight, within +10 mils. ILLUMINATION NOTE: For the following evaluations apply 24 volt dc EVALUATION power supply to electrical input circuits. 22 Counters Counter illumination shall be sufficient for numerals and markings of each counter to be clearly distin- guishable when observed in darkened area. -- Reticle When observed in darkened area with reticle LED energized with 24 volts dc, reticle markings must be clearly defined. 2-8