Bell and Howell 1598, User Manual

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P a n chromatic TQIII & TQIII Specialist User Manual
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65 Projection lens. The surface coatings on high-quality lenses are delicate and it is better to let a
few specks of dust stay on a lens than to clean a lens too often. When you suspect that dirt on
either of the exposed surfaces is affecting picture quality, remove the lens by rotating the focus
control 65a towards the rear of the projector and withdrawing the lens 65b from its mount. Use a
very soft brush or puffer brush to remove loose dust from the lens surface. Then, with a clean lens
tissue, gently polish the surface clean, breathing on it if any marks are difficult to remove. Take
care never to touch the surface of a lens with a bare finger. If this happens by accident, cleaning
should be done immediately because a fingerprint can leave a permanent pattern on the lens. If
there are any marks which cannot be removed with gentle polishing, resist the temptation to rub
more energetically. Use a lens tissue just moistened with a proprietary lens cleaning fluid and
afterwards polish the surface dry with another clean tissue. To replace the lens, insert it in its
mount while rotating the focus control towards the front of the projector.
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Sound System. The glass surfaces of the sound optic are well protected by the exciter lamp
cover and will seldom need attention. If the maximum sound output obtainable seems to have
diminished, apply a soft and clean brush carefully to the area (arrowed) between the rear of the
sound optic and the sound drum. Any other cleaning of the sound optical system should be done
by a Bell & Howell audio-visual dealer, who will make any necessary readjustments if the precise
alignment of the system is disturbed. The magnetic head should occasionally be taken out (Stage
60) and lightly brushed to remove any particles of magnetic oxide. Do not attempt to remove
obstinate accumulations of oxide from the head with any tool or fluid. This is a delicate
component adjusted in the factory to a high degree of precision. If it cannot be cleaned by gentle
brushing, ask your dealer to do the job.
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Cables. It will not in any way affect the performance of your projector, but it will make
projecting more pleasant, if you run the power and speaker cords through a duster before coiling
them up at the end of a presentation. Often lying on the floor, they quickly become dirty and,
unless cleaned, will mean that you start your next presentation with soiled hands.
Service
68 For any advice not given in this instruction manual and for any adjustments, consult a Bell &
Howell audio-visual dealer. He will be glad to help, applying to your problem not only his expert
knowledge but also, if necessary, the special servicing tools and instruments made or
recommended by Bell & Howell. Although the projector will run for long periods without any
attention, other than the regular cleaning you do yourself, it is wise to ask the dealer to examine it
from time to time - preferably annually if the machine is in frequent use. He knows how to restore
its performance to its peak, if there has been any deterioration you have failed to notice, and so
keep the projector serviceable for many years to come.
Storage
69 The projector should be stored in a dry place away from excessive heat. If your use of it entails
frequent road journeys, a "mattress" made of a thick sheet of foam rubber is sensible investment
because it will reduce the vibration which might otherwise shorten the life of your lamps.