TM-9-1240-400-34&P Technical Manual for M109 Telescopes and Mounts Download
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TM 9-1240-400-34&P CHECKING ILLUMINATION OF M137 TELESCOPE MOUNT 1 Perform the illumination inspection with M137 telescope mount in a darkened area and connected to any suitable 24-volt d.c. power sup- ply. 2 With 24 volts d.c. applied to the M137 telescope mount power source connector (1), turn variable resistor knob (2) between minimum and maximum illumination and observe that lamp (3) in extension light (4) brightens and dims. 3 Place toggle switch (5) to ON and observe that vial and counter lights (6) illuminate. The illumination shall be sufficient for level vial markings and counter numbers to be clearly defined. Place toggle switch (5) to OFF. CHECKING M137 TELESCOPE MOUNT RIGIDITY Apply a 20.0-lb (9.1-kg) load with spring tester gage to right side of upper assembly. Release load and record. Repeat on left side of upper assembly. Movement shall not exceed 0.25 mils at 0 mils, 0.75 mils at 800 mils, 1.75 mils at 1100 mils, and 3.50 mils at 1333 mils. If requirements cannot be met, check for loose components. 5-69