It is specifically recommended that a spare parts kit for the particular installation be. kept on
hand, and that its supply of spare parts (with particular reference to fuses and Radiotrons) be
maintained. These kits are obtainable from RCA Photophone and contain spare parts which
may be required for emergency repairs.
270. Summary of the Daily Maintenance Requirements. -The following is a list of things which
should be done every day:
(a) Fill grease cup of the viscous damping device with Alemite grease. Screw down one turn
for every four hours of running in both the sound heads and the turntables. See sections 71
(b) Oil projectors, turntables, chains, motors, and M-G sets and converters where used.
(It is very important to see that the equipment receives sufficient oil, but care should be taken
to see that the bearings are not drenched, particularly in the sound head, as oil may be thrown
on the film and on the optical system. Take no chance of dry bearings, but do not drench them
(c) Run the projector 15 minutes before starting the show.
(d) Clean sprockets and sound gate, taking particular pains with the constant speed sprocket.
(e) Polish condenser lenses in optical system. Keep the sound head clean.
(f) Check exciter lamp adjustments and see that exciter lamps are all clean.
(g) Check the storage batteries for state of charge, and cleanliness.
(h) Check the voltages at the amplifier panels.
(i) Check sound from each projector by means of the card "test", and scratch needle of each
turntable pick-up before each show.
(The click test is made by passing an opaque card in and out through the exciter lamp beam at
each sound gate alternately. With the amplifier turned "on" and all switches properly set for
sound-on-film operation, a click in the loudspeaker should be heard.
With all switches properly set for sound-on-disc, scratch the needle in each pickup alternately.
A scratching noise should be heard in the loudspeakers.)
(j) Test all power amplifiers with the "click" test by plugging the monitor into one at a time.
(k) Test both voltage amplifiers with the "click" test.
271. Some Things Which Should Not Be Done:-
(a) Do not put any thing but oil on the drive chains.
(b) Do not turn "off" the voltage amplifier before turning "off " the power amplifier.
(c) Do not fade to the starting projector too soon.
(d) Do not try to adjust the optical system.
(e) Do not forget to close the sound gate when using sound film.
(f) Do not forget to keep the aperture of the sound gate clean.
(g) Do not use reels with small sized hubs when using the large size take-up pulley as the
small hub will not take up the film fast enough, and the film will pile up in the lower part of the
sound head. When using a reel with a small hub use the two inch pulley. The five inch pulley
should be used with large hubbed reels.
Copyright 1930 RCA Photophone, Inc.