RCA 400 User Manual

10
taking care not to touch the lens surface with the
fingers.
d. The sound optical unit (lena tube). This
unit is mounted in the clamp portion of the SOUND
OPTICAL BRACKET (figures 1 and 7). Unscrew
the EXCITER LAMP HOUSING THUMBSCREW and
swing the assembly outward. Remove the exciter
lamp from its socket. Clean the exposed front and
rear glass elements of the sound optical unit with
a lint free cloth; do not use any other means for
cleaning this lens. Do not loosen the clamp or re-
move the optical unit from its mounting; proper
positioning of the unit for optimum sound quality
requires tools and test facilities available only in
the factory or in qualified repair shops. Replace
the exciter lamp after cleaning the optical unit.
2. Cleaning /amps. The projection lamp and
the sound lamp should be cleaned occasionally
as necessary.
a. The projection lamp (figure 5). To re-
move this lamp, press down on it firmly and turn
it counterclockwise about 90 degrees until it
releases from its socket. Wipe it clean with a
cloth and return it to its original position. Be very
careful not to leave any fingerprints on the clear
portion of the lamp; such prints will burn into the
glass and definitely impair the lamp efficiency,
fie sure the lamp is cool before attempting to re-
move it, or use a heavy cloth to protect the fingers.
Figure 6 — Lamp House Open for Servicing
"Junior" Model
b. The sound lamp. Open the optical bracket
as shown in figure 7 and clean the lamp in place.
3. Cleaning mechanical members. Film dirt will
collect on the aperture plate, the film pressure
shoe (which presses the film against the aperture
rails), the sprockets, the sound drum pressure
roller, and on the sound drum. Do not use a knife
or any other metal instrument, for removing the dirt.
An orangewood stick, or similar tool, may be used
to dislodge hardened film emulsion particles.
a. The aperture plate. Open the picture gate
and wipe the aperture plate with a soft cloth to
remove dirt. Use a toothpick, if necessary, to re-
move dirt from corners. Clean the two side pressure
shoes with the bristle brush supplied with the
projector. Clean the film pressure shoe in the same
manner as the aperture plate. A small amount of
thinner or cleaning fluid may be used to soften
caked emulsion for removal. After all visible dirt
and emulsion have been removed, inspect and feel
the film contacting surfaces of both the aperture
plate and the film pressure shoe to make sure they
are smooth and free from all foreign material,
scratches and pits. The presence of scratches or
pits may ultimately call for replacement of the
part involved, since film emulsion piling up and
baking in such depressions cause film scratching.
b. The sprockets. Clean the sprockets with
bristle brush. Be sure that all dirt is removed from
the teeth.
c. The sound drum pressure roller. Wipe it
clean with a soft cloth moistened with carbon tetra-
chloride. Rotate the roller to clean it all around.
d. The sound drum. Clean the sound drum in
the same manner as the pressure roller. Be sure
to clean the back edge of the drum where the film
sound tracks overhang. Wrap a clean cloth around
the left forefinger and insert the finger between the
guide roller and the tension roller. Hold the cloth
against the back edge of the drum and rotate the
drum with the right forefinger. Cleaning the back
edge of the sound drum from the left side in this
manner minimizes the possibility of disturbing the
small mirror behind the drum on the right, which
reflects the light beam from the sound optical unit
into the phototube.
Replacements
The projection lamp, and the sound lamp are
the most likely components to require replacements
during a show. Spare lamps should be kept conven-
iently at hand.

RCA 400 Specifications

General

Power Supply	9V Battery
Type	Multimeter
Display Type	LCD
Dimensions	138mm x 69mm x 31mm
Weight	Approx. 170g (including battery)