3-50
TM 9-1240-401-34&P
3-29. M118A2/M118A3 ELBOW TELESCOPE FINAL INSPECTION AND ADJUSTMENT
- continued
c. PARALLAX ADJUSTMENT
1
2
3
4
5
6
View through M118A2/M118A3 elbow telescope
eyepiece (1) and move head from side to side. Ap-
parent movement between telescope reticle
crosslines and target image should not exceed
0.15 mil (the width of reticle line) as measured on
collimating projector (2) reticle.
If error exists, remove setscrew (3).
Using 2 and 2-1/64 inch tubular spanner wrench
(Item 33, appx F), remove cell assembly (4).
Using 1-7/16 and 1-29/64 inch tubular spanner
wrench (Item 30, appx F), make adjustment to cell
(5) by rotating cell (5) until reticle crosslines are
parallel.
Install cell assembly (4) using 2 and 2-1/64 inch
tubular spanner wrench (Item 33, appx F).
Install setscrew (3).
d. EYEPIECE FOCUS ADJUSTMENT
1
2
3
4
5
6
7
8
Rotate eyepiece of dioptometer (1) until reticle
lines of dioptometer are in sharp focus.
Place dioptometer (1) in front of M118A2/M118A3
elbow telescope eyepiece (2).
Look through dioptometer (1) and slide dioptometer
objective back and forth until M118A2/M118A3 el-
bow telescope reticle lines appear sharp and clear.
Remove dioptometer (1), without disturbing its set-
ting, and note reading on side of dioptometer. Eye-
piece focus, as indicated on dioptometer (1),
should be-0.75 to-1.0 diopter.
If error exists, remove setscrews (3 and 4) from
eyepiece arm.
Make adjustment to cell assembly through hole
where larger setscrew (4) was removed.
Recheck eyepiece focus.
Install setscrews (3 and 4). Do not overtighten.