Objective Tube Assembly - TM-9-6650-235-13-P0014

ARMY

TM 9-6650-235-13&P

MARINE CORPS

TM-08552A-13&P

1-9.

LOCATION AND DESCRIPTION OF MAJOR

COMPONENTS (CONT).

d. Objective Tube Assembly. The two-section

objective tube assembly contains lenses that transmit the

image from the mirror. Both sections must always be

used. This assembly connects to one of the two

illuminating head assemblies. The end of the first

section (1) of the objective tube assembly connects to

the illuminating head assembly. The outside surface of

the tube sections has graduation marks of 1.0 inch, 6.0

inch, and 1.0 foot intervals, with the 6.0 inch and 1.0 foot

marks completely encircling the tube. A line runs on

section I within 3.0 inches and on section II within 4.0

inches of the length of the tube through the center of the

graduation intervals to assist in the assembly of the

sections and to provide a reference point for stating the

o'clock position of cannon bore defects.

OBJECTIVE TUBE ASSEMBLY

e. Illuminating Head Assembly. One end of the

illuminating head assembly connects to the objective

tube assembly and has a lock assembly which locks in

the first section of the objective tube assembly. The

same end has three terminals that connect to three plugs

of the objective tube assembly for lamp power supply.

The mirror assembly (1) mounts on the adjustable holder

to provide a field of view (FOV) ranging from a point

ahead of the lamp, to a right angle to the tube centerline.

The lamps are incandescent; one is 75 watts for 115-volt

operation and the other is 100 watts for 24-volt operation.

ILLUMINATING HEAD ASSEMBLY

1-4