Rousing - continued

TM 11-2323

(7) The projection stage of the PH-637/PFP, the PH-637A/

PFP, and the PH-637B/PFP is a plate glass cover, held

in place over a 10- by 10-inch opening by retaining strips.

The Fresnel condenser lens rests in grooves under the plate

glass cover. On the PH-637C/PFP, the projection stage is

a sheet metal unit which is attached the plate glass cover

and the Fresuel condenser lens. The unit is held in place

by two knurled projection-stage retaining screws located on

both sides of the housing, toward the rear, allowing the pro-

jection stage to pivot up and to the rear.

(8) In front. of the, projection stage, on top of the housing, is a

groove that holds a grease pencil used for marking cello-

phane or plastic held on the projection stage. (On the

PH-637C/PFP, the pencil groove is formed by the converg-

ing angles of the sheet metal at the front of the projection

stage and the rear of the front shelf when the front shelf

is raised.)

(9) On the right side of the housing of the PH-637/PFP, the

PH-637A/PFP, and the PH637B/PFP, next to the support

post hole, is a clamping knob used to lock the support post

in position. ( O n t h e P H - 6 3 7 / P F P , t h e c l a m p i n g k n o b i s

located on the rear of the yoke.)

(10) The housing contains an optical system composed of a re-

flector, a projection lamp glass condenser lens, a heat-

absorbing filter (PH-637B/PFP and PH-637C/PFP only),

a rear surface mirror, a Fresuel condenser lens, and the glass

cover of the projection stage. T h e h o u s i n g s o f t h e P H -

637A/PFP and the PH-637C/PFP also contain a cellophane

roll attachment, (d below).