(A) GENERAL DISCUSSION
224. Introduction. -The RCA Photophone equipment has been ruggedly designed with a view to
reducing the required maintenance to a minimum. Complicated mechanisms and mechanisms requiring
delicate adjustments have been avoided as much as possible. However, no matter how well equipment
containing as many inter-related parts as that required for "talking-movie" reproduction is designed,
trouble may develop during the operation of the equipment.
Troubles which develop during operation can be reduced to a minimum, if not entirely eliminated, if the
equipment is properly taken care of and checked over frequently and thoroughly.
Cleanlines and neatness are of prime importance in the prevention of trouble. Dirty equipment is certain
to give trouble. Dirty sound heads will cause distorted reproduction and loss of volume, and may be the
cause of "no-sound". Dirt on storage batteries will cause noisy reproduction and shorten the life of the
battery. Dirty commutators will cause a hum in the loud speakers. Dirty exciter lamps, photo cells, or
lenses will cause distortion and lessened volume.
Care should be exercised, when cleaning the equipment, to prevent disturbing the adjustment of the
various parts of the apparatus. This is particularly true of the optical system, which is delicately
adjusted and should not be disturbed when the sound head is cleaned.
Even with the best of care troubles may develop occasionally which require immediate correction, and,
although such emergencies should seldom occur, it is important that the operator be ready to meet them
with a definite plan of action.
It is the purpose of this chapter to state briefly the requirements of proper maintenance, to outline the
procedure to be followed in case of trouble, and to state the more common causes of trouble and the
method of correction. It is recommended that the operator study carefully those parts which apply to the
particular type of equipment which he is operating.
225. General Discussion. -The troubles which may be experienced with RCA Photophone equipments
depend upon the type of equipment used, but there are some which might occur with any of the
Probably the most common of the troubles experienced are those which are due to "slip-ups" in the
operation. Therefore, it is important to check over the operating procedure before looking elsewhere for