Figure 8-4. Observation telescope-optical elements and optical diagram.

TM 9-258

b. The telescope image is erected by means of

two Porro prisms and magnified by the lenses in the

eyepiece, as shown in figure 8-4.

The telescope is of 20 x power with a field of

screw is provided for elevating or depressing the forward

end of the telescope.

view of 20 12 minutes, is approximately 14 1/2 inches

d. The telescope is strapped in position in a

long, is focused by turning the knurled focusing sleeve

cradle which in turn is mounted on the corresponding

and is mounted on the tripod which supports the

tripod. The tripod folds into a compact unit and fits into a

instrument about 11 inches above the ground. With this

carrying case for ease and convenience in

tripod the telescope can be swung around to any desired

transportation.

position. An elevating

Section II. ARTICULATED TELESCOPES

mounted coaxially with the gun.

8-5.

General.

b. The optical system diagram of one type of

a. The articulated telescope is a component of

articulated telescope is illustrated in figure 8-5.

the direct free control system and is generally

Figure 8-5. Articulated telescope - optical system diagram.

8-3