CHAPTER XV
TYPE PG-5 PORTABLE EQUIPMENT
272. General Description. -The PG-5 Portable Equipment, although similar in function to all Photophone
reproducing equipments, is quite different in design and purpose. Since the main consideration has
been portability, without attendant loss of quality of reproduction, the appearance and construction of
the various parts is therefore quite unlike the theatre equipments.
The projector is specially designed, combining both projection and sound reproducing mechanisms,
and is a very compact unit. The amplifier is a self-contained unit which needs only a standard 110 volt,
50 or 60 cycle, AC supply, and furnishes all voltages necessary for its operation without the use of
batteries or motor-generator sets. A portable screen and loud speaker are supplied with each equipment.
The equipment can be used in districts where 125 volt DC is the standard power supply, but converting
equipment is required to change the DC power to 110 volt, 60 cycle power. Converters can be supplied
for this purpose.
The entire equipment is quickly set up or repacked. A completely portable set including two projectors,
an amplifier, loudspeaker, screen and accessories packs into six trunks, the total weighing about 920
pounds. Several schedules are supplied, so that either one or two projectors and a completely portable
or semi-portable loudspeaker are available..
Each trunk has been specially designed, carefully fitted and padded to withstand vibration and handling
in shipment. An accessories trunk contains the projector film magazines, a double set of amplifier tubes,
a supply of projection and exciter lamps, tools, film cement and a film rewinder and splicer.
The screen is quickly assembled from parts which fit very compactly into its trunk, and the speaker also
is designed to be quickly unpacked and placed ready for operation.
273. Description of Projector. -The Photophone portable projector used in PG-5 equipments
accommodates standard film, sound or silent, and projects it at a film speed of 90 f eet per minute. The
entire mechanism is enclosed in a steel cabinet,, on which are mounted the two 1000 foot film magazines,
removable for packing. It rests on telescoping legs about thirty inches from the floor, and a tilting screw
on the mounting frame placed under the front of the projector provides for centering of the picture on
the screen. The angle of projection can also be altered by adjusting the front and rear telescoping legs.
See Figure 130.
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