TM-9-1240-401-34&P Technical Manual for M109 Telescopes and Mounts Download
Page 179 of 344
5-5 TM 9-1240-401-34&P Item No. 12 13 14 15 16 Item To Be Inspected GUNNER’S AID COUNTER RESET COUNTER LENS AZIMUTH COUNTER COUNTER LEDS Procedures Rotate gunner’s aid knob (11) to stop in both directions. Gunner’s aid counters (12) must have an excursion of 50 roils in each direction before contacting stops at extremes. Rotate reset counter knob (8) while observing reset counter (13). Reset counter (13) must be able to reset to 3200 roils from any counter position. Rotate azimuth knob (10) while observing reset counter (13). Reset counter (13) shall follow azimuth counter (15) within 0.25 mil when azimuth knob (10) is rotated. Set -50 roils on gunner's aid counter (12) (right) and check that reset counter (13) reading increases by 50 ± 0.5 roils. Set +50 roils on gunner's aid counter (12) (left) and check that reset counter reading decreases by 50 ± 0.5 roils and that azimuth counter (15) reading does not change. Inspect lens (14) for dirt, fungus, or condensation which may obstruct view through eyepiece; must be clean and moisture free. Rotate azimuth knob (10) clockwise, then counterclockwise while observing azimuth counter (15). Azimuth counter (15) indication must increase when azimuth knob (10) is rotated clockwise and decrease when azimuth knob (10) is rotated counterclockwise. Rotate azimuth knob (10), gunner’s aid knob (11), and reset counter knob (8) to lowest digit, with the lowest digit coinciding with its respective index line. Check that remaining numbers are in alinement within 1/16 inch (0.16 mm). Inspect counter LEDs (16) by observing counter numerals; numerals shall be clearly distinguishable in darkened area with 24 volts DC applied.