TM-9-1240-400-34&P Technical Manual for M109 Telescopes and Mounts Download
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TM 9-1240-400-34&P 3 Rotate azimuth fixture ring (6), counterclockwise, to 800 mils. 4 Rotate deflection knob (1), clockwise, until reticles coincide. If coincidence point is overtraveled, rotate deflection knob, counterclockwise, one-half turn past coincidence point and repeat this step. 5 Deflection counter (3) should increase by 800 mils + 1.0 mil and reset counter (4) should increase by 800 mils + 1.0 mil. Record readings. 6 Rotate deflection knob (1) approximately one full revolution clockwise. Rotate deflection knob slowly, counterclockwise, until panoramic reticle coincides with collimator projector reticle. Record readings. Be careful not to overtravel coincidence point. If coincidence point is passed, repeat. 7 Difference between readings in steps 5 and 6 is amount of backlash and must not exceed 0.5 mil when read on azimuth counter (5) and 0.75 mil on reset counter (4). 8 Rotate azimuth fixture ring (6), counterclockwise, to 1600 mils. 9 Repeat steps 3 thru 7. Deflection counter (3) and reset counter (4) should indicate 4800 mils. 10 Repeat steps 3 thru 7 above, every 800 mils, until head assembly (2) completes 2 full revolutions. 11 Replace deflection counter (3) if readings exceed tolerance in step 7. Refer to page 2-42. 12 Replace reset counter (4) if readings exceed tolerance in step 7. Refer to page 2-42. 2-73