TM-9-1240-401-34&P Technical Manual for M109 Telescopes and Mounts Download
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6-11 TM 9-1240-401-34&P I b. INSTALLING M42 PERISCOPE ON INSPECTION FIXTURE 1 Mount M42 periscope (1) on inspection fixture (2), making sure that all mating surfaces are free of dirt, burrs, and other defects which would interfere with proper seating. 2 Secure M42 periscope (1) to inspection fixture (2) using three screws (3). I C. IMAGE TILT ADJUSTMENT 1 2 3 4 5 6 Check collimation by viewing reticle images through auxiliary telescope (1). Image of auxiliary telescope (1) reticle intersection point should coin- cide with reticle image of collimating projector (2). If auxiliary telescope (1) reticle does not coincide with image of collimating projector (2) reticle, ad- just cover assembly (3) by turning three setscrews (4). Check image tilt by viewing image of collimating projector vertical reticle line through auxiliary tele- scope (1). Vertical reticle line image should be ver- tical within 1 degree as measured on auxiliary tele- scope reticle (ref. TM 9-254). If image tilt is not within specified limits, adjust the cover assembly (3) by turning three setscrews (4). Recheck collimation (step 1) and adjust as neces- sary (step 2). Apply adhesive to three setscrews (4) after final adjustment.