Motion-Picture Projection Unit, Portable

a portable device for showing mainly narrow-gauge 16-mm motion pictures in small viewing rooms that are not equipped with stationary units. During the period of the formation and development of Soviet cinematography, portable projection units played a very large role in ideological, political, and scientific-cultural propaganda over the vast territory of the USSR, particularly in rural regions. Portable projectors are used in remote rural regions, in field camps, in winter quarters, during exploratory expeditions, and in lumber camps and other similar installations; they are also widely used in educational work.

The equipment of a portable projection unit usually includes a projector, an audio amplifier for the electric signals of sound frequencies, a loudspeaker, a compensator for voltages of 127 and 220 V, and a retractable screen. During the showing of a film, the projector is placed either on a tripod stand (for 35-mm films with an optical sound track) or on the housing of the amplifier (for 16-mm films with optical or magnetic sound). For areas that do not have electricity, the portable projector equipment may include a small portable generator. The total electric power required by the portable projector is 600–700 watts for 35-mm films and about 500 watts for 16-mm films. The weight of the entire set (without the generator) is 100–110 kg for 35-mm films and about 70 kg for 16-mm films, and the nominal power of the sound reproduction equipment is about 10 watts. The projection unit is transported by motor vehicle; in certain instances specially equipped projector trucks are used.