MIL-DTL-48554 Telescope, Panoramic - M137A2, M137A3, And M137A4This specification covers Telescope, Panoramic ?√ M137A2, M137A3, and M137A4 which are types of panoramic telescopes which provide four-power magnification and a ten-degree field of view. They are equipped with numerical counters which indicate azimuth settings and corrections.

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MIL-DTL-48554B

tolerance specified in 3.10.2 of the zero level line on the target. This test shall also be

conducted in the counterclockwise direction.

4.10 Counter mechanism.

4.10.1 Rapid boresight retention. Position the telescope as specified in 4.4. Turn

the azimuth knob at the speed specified in 3.11.1 until the head has made one revolution.

Caution should be taken to avoid overtravel in the line of sight coincidence previously

obtained. The boresight setting shall read 3200 mils within the specified limit of 3.11.1 as

read on the azimuth counter and the deflection or bearing counter shall follow the azimuth

counter within the limit specified in 3.11.1. Backlash shall be removed prior to traversing

the azimuth knob for this test. This test shall be repeated in the opposite direction.

4.10.2 Deflection or bearing counter. Position the telescope as specified in 4.4.

Rotate the azimuth knob to bring the deflection or bearing counter to zero. Place the

deflection counter lever in the "Release" position. Rotate the azimuth knob in the same

direction used to bring the deflection or bearing counter to zero to bring the telescope

reticle into coincidence with the target reticle. Place the deflection counter lever in the

"Engage" position. Rotate the azimuth knob in the opposite direction a minimum of two

turns. Reverse direction and realign the telescope reticle with the target reticle without

overtravel. The value as read on the deflection or bearing counter shall be within the

accuracy specified in 3.11.2. This test shall be repeated at 800, 1600, 2400, 3200, 4000,

4800 and 5600.

4.10.3 Correction counter excursion. The correction counter knob shall be

manually rotated until the counter has traveled to its full excursion. The counter shall read

between the limits specified in 3.11.3. This test shall be performed in both the "L" and "R"

directions.

4.10.4 Correction counter affect on deflection or bearing counter. The panoramic

telescope shall be positioned as specified in 4.4. Turn the correction knob to 95 mils, "L"

direction. With backlash removed, re-establish the line of sight by placing the telescope

reticle into coincidence with the collimator target reticle within the applicable limits

specified in paragraph 3.11.4. The deflection or bearing counter reading shall have

changed by the applicable amount specified in paragraph 3.11.4. This test shall be repeated

in the "R" direction.

4.10.5 Correction counter setting. The panoramic telescope shall be positioned as

specified in 4.4. Turn the correction knob to 95 mils, "L" direction. The azimuth counter

shall not have changed more than the applicable specified limit in 3.11.5. With backlash

removed, re-establish the line of sight by placing the telescope reticle into coincidence with

the collimator target reticle within the applicable limits specified in paragraph 3.11.5. The

azimuth counter shall not have changed more than the applicable specified limit in 3.11.5.

This test shall be repeated in the "R" direction.