From a 1952 UK catalogue,
about the G.B. Bell and Howell 613 - "British-built
throughout, Model 613 incorporates all the features that
have made G.B.-Bell & Howell Projectors famous all
over the world, PLUS greater film capacity. Projector
lamp, 110 volts, 750 watts. Lens Taylor Hobson 2 inch
f/1.65 'bloomed.' Still projection, immediate projection
of any one frame. Reverse projection, for quick
repetition of any scene. Lubrication, metered and
filtered.Spool capacity, up to 800 ft. Pilot light, built
into mechanism. Sprockets, with single teeth for
projection of single and double perforated films.
Tilting, by knob on projector base. Weight 13 and three
"Model 613 for 110-volt A.C./D.C. operation
"Transformer for 200-250 volt A.C. £12 10s.
Resistance for 200-250 volt A.C./D.C. £12 10s.
"Model 613R, for 110-250 volt A.C./D.C., with built-in
resistance, 400 watt lamp £80
"Carry case £7 10s."
These instructions also apply to the 613R, except
the instructions about setting the power supply.
on Mastering the Art of Efficient
Preparing for the
Be sure that you are thoroughly familiar with the
instructions, threading and operation of the projector.
Make sure the circuit to which the equipment is to be
connected is adequately fused and that the plugs and
sockets are in good condition. Make sure that the correct
voltage is applied to the machine in accordance with the
instructions (see Connection to Mains
Supply). Always stand the projector on a firm
support. Keep your cables well away from gangways or
other places where there is a danger of members of your
audience tripping over them.
Lubricate the projector according to the directions
(see Projector Lubrication). Make
quite sure that all film contact surfaces are clean and
free from deposits of film emulsion. A deposit of hard
film emulsion can ruin many reels of film. Never use a
metal instrument for removing film emulsion from the
contact surfaces - a bone or hard wood scraper will clean
without scratching the polished surfaces. Make sure all
rollers revolve freely.
Check for bent spools. Allow the projector to run for
several minutes before inserting the film to ensure
smooth running at constant speed. Whilst the machine is
running, test for elevation and required picture size.
Check also for cleanliness of the edges of the picture
masking. Make sure that the light beam will clear the
heads of your audience. A supply of spares is always a
wise precaution and should include a projector lamp,
pilot lamp and a set of belts. Accessories such as
additional lenses, film splicer and re-winder are always
The Show is
It is unprofessional to show the leader numbers on the
screen - the hand is quite an effective mask for this.
After focusing, use the lens lock. Remain near the
projector throughout the performance in order to make any
necessary adjustments. Watch the film and the screen for
development of scratch. If a scratch is developing, stop
the machine at once, unthread the film from the lower
sprocket and trace back until the source of damage is
Common causes of scratch are:-
- Dirty picture gate
- Dirty rollers or sticking rollers (causing
- Too large or too small a loop (causing film to
drag on another part of machine).
Common causes of perforation damage are:-
- Incorrect threading (perforations not
registered with sprocket teeth)
- Idler rollers out of alignment
- Fierce take-up
- Damaged sprocket teeth
- Bent spools
(piece omitted about care of Library Films)
The projector reaches you with folded spool arms.
Commence by turning the arms fully clockwise into
position, making sure that the spring belts are correctly
seated in their pulleys and are not crossed. Make sure
the take-up belt is seated in the guide pulleys.
The feed spool arm has two belts; that nearest to the
arm is the reversing belt (RV), which drives the
feed-spool as a take-up when the projector is running in
reverse. The outer belt (RW) drives the feed-spool when
the projector is being used for rewinding.
The Take-up arm has two pulleys: that nearest to the
spool is used for normal running, when the Rewind-Run
Lever at rear of Top Arm will be in 'RUN' position (i.e.
forwards towards spool).
For Rewinding, the Rewind-Run Lever should be moved,
with the machine stopped, to REW position. This movement
is assisted by slight movement of the Hand Set Knob. The
Take-up belt MUST be moved over to the outer Take-up
Pulley, and the Motor must be run in forward direction. A
convenient method of changing the belt from one pulley to
the other is to 'fold' the take-up spool arm slightly,
this slackens the tension on the belt, which may then be
Operate the Projector
Familiarize yourself with the elements of the
machine's construction which you must thoroughly
understand if you are to operate it with trouble-free
efficiency. A complete study of these instructions is
recommended before operating the projector.
Operating from 200/250 volts
To operate on 200/250 volts alternating current an 850
watt 200/250 volt to 110 volt transformer is
Make sure that the transformer tapping screw is set to
correspond with the voltage of the mains supply in use.
The transformer is fitted with a voltage selevtor panel
carrying two tapping screws. The panel is marked
10-0-200-220-240 volts. One tapping screw must always be
in the 0 or 10 volt tapping. When in the 0 tapping the
voltage selected is as indicated by the second tapping
screw. When in the 10 volt tapping the voltages as
selected by the second tapping are increased by 10 volts,
i.e. 210-230-250 volts. The life of the lamp can be
conserved by utilising a voltage tapping or resistance
above that of the mains supply, e.g. mains supply voltage
220, tapping 230. This results in under-running the
In order to make certain of the exact voltage of the
mains supply it is advisable to consult the local
electrical authority, or if this is not practicable to
measure the mains voltage with a voltmeter. It is not
sufficient to examine the house meter or a lamp in use
and take the presumed voltage from these.
Plug the 200/250 volt side using the mains lead
provided, into the wall socket, first making sure that
the earthing lead is properly connected to the earth pin
in the plug. Plug the 6 ft. lead into the 100 volt socket
on the transformer and connect the other end into the
Operating from 110 volt Alternating
Connect projector direct to the mains using 25 ft.
Operating on 200/250 volts Direct
A Model 613 Line Resistance is required, one side of
which is connected direct to the mains and earthed as for
A.C. operation, the output being connected to the
Projector by means of the 6 ft. lead provided. In all
cases, the resistance unit tapping must be adjusted to
correspond with the voltage of the mains in use.
The Standard Line resistance unit supplied is suitable
only for 750 watt projection lamps; it may also be used
with A.C. supply.
When the projector is supplied by 200/250 D.C. or A.C.
through the normal resistance the 110 volt pilot lamp
must be replaced by a 200/250 volt lamp of suitable
wattage. The brilliance of a pilot lamp of 200/250 volts
used as stated above, will be greatly reduced when the
motor is switched on.
Operating on 110 volts Direct
The Projector is connected direct to the mains as for
A.C. Operation above.
On the base under the motor housing is a switch marked
'AC' and 'DC'. Set the switch for the type of current
according to your mains supply. No damage will result if
the motor is set for AC when the current is DC, but the
speed of the motor will be too great to be controlled by
the Speed control. If set for DC when the current is AC,
sufficient speed cannot be attained even though the speed
control is fully released. Two switches will be found on
the rear of the base. The line switch controls the motor,
the 'lamp' switch controls the projector lamp. The
projection lamp will not operate unless the motor is
running. The projection lamp should be turned off while
rewinding to preserve the life of the lamp.
The pilot lamp is automatically switched on when it is
pulled out and automatically turned off when it is pushed
back into the housing. This lamp operates independently
of the motor or lamp switch. To replace the pilot light
bulb, unscrew the guard by turning it
Be sure that the mains and 'lamp' switches are in the
off position. Connect the projector to the mains in
accordance with the instructions (see Preparing
to Operate the Projector). Turn on the line switch
and 'lamp' switch. With the projector operating and the
lamp turned on, loosen the lens locking screw LL, Figure
1, by turning to the left, and slide the lens L forward
or backward until the outlines of the frame are sharply
Further to sharpen the focus, revolve the lens first
in one direction and then in the other. Lock lens in
position by turning the tilt adjustment knob. If the
projected image is larger than the screen, move the
projector closer. If the image is too small, move the
projector farther from the screen. If room size limits
the 'throw' select the correct lens, as indicated in the
table (see Main Pictures
If the light on the screen flickers, turn speed
control knob 7 counter-clockwise to increase the speed.
The proper projection speed for silent films is 16 frames
per second or just above the point of noticeable
Place the loaded spool on the spindle of the top spool
arm. The films should be wound on the spool with the
emulsion, or dull, side out (Exception: duplicates from
original reversal film, prints of 16 mm. negatives and
Kodachrome films are wound and projected with the
emulsion side in.) The films should come off the bottom
of the spool as shown and the objects on the films should
be up-side down as they pass through the projector
mechanism. Lead the film above the roller and below the
sprocket. Slide the film as far as it will go. Holding
the film snugly around the sprocket with the right thumb
and index finger, press on the tab to open the guard.
Pull gently on the film until the perforations seat on
the sprocket teeth. Then release the tab locking the film
on the sprocket. Lift the lever upward to open the film
gate. Place the film in the channel and form the first
loop, following the loop outline on the side of the gear
case, being certain that it is fully seated in this
channel. Form the second loop, according to the outline
on the gear case, and slip the film over the second
sprocket. Again press the film as far toward the
projector as it will go and, while maintaining correct
loop size, lock the film on the sprocket. Close the gate
by pressing down the lever as far as it will go. With
clutch disengaged turn the hand setting knob several
clockwise revolutions. This will engage the film with the
claw teeth. Should the lower loop slide upward, continue
to turn the hand setting knob until the claw teeth are
withdrawn when the film may be pulled down to re-set the
loop to the outline on the gear case. It is not possible
to move the film downward through the gate unless the
claw teeth are withdrawn. Again, test the threading with
the hand setting knob. the film should pass over the top
of the take-up spool and is held by placing the end of
the film in the slot in the hub. The slack in the film
should be removed before starting the projector by
revolving the take-up spool clockwise.
Projecting you should be able to answer "Yes"
to the following questions.
- Have you read the preceding instructions?
- Have you cleaned the aperture and optical
- Are both loops of the correct size?
- Is the film properly engaged on all
- Is the film gate closed?
- Is the film properly started on the take-up spool,
with all slack removed?
- Have you tested the threading by turning the hand
- Have you learned from the ensuing sections of this
manual, how to use the clutch, frame, rewind-run lever
and reverse-forward switch?
- Is the clutch engaged?
- Is the reverse switch set at 'Forward'?
- Is the rewind lever at 'run' position?
- Is the A.C./D.C. switch correctly set for the
mains in use?
Turn on the mains switch, engage the clutch and turn
on the lamp. As the first title or picture appears on the
screen, carefully revolve the lens, first in one
direction and then the other until the title or the
picture appears in sharp focus. Lock lens with the
If the picture frame line shows on the screen, turn
the framer knob 22 to make the frame line disappear. If
the framing moves the picture off the screen, readjust
the tilt control.
To project a still picture, the clutch control lever
34 should be pushed back thus disengaging the projector
mechanism. If no picture appears on the screen, the
closed section of the shutter is obscuring the light. A
small movement of the hand setting knob will bring the
open section of the shutter into correct position, thus
permitting the projection of still pictures. It will be
necessary to adjust the lens to focus a still picture.
Refocus when motion is resumed.
Always disengage the clutch before changing the film
movement direction. The reversing switch 32 is on the
rear of the motor housing. By pushing this up to the
'reverse' position the film may be reversed at any time
To rewind the film, lead the end of the film on the
lower spool arm to the empty spool on the top arm and
fasten to the spool.
On the upper spool arm is the rewind lever, (see
Disengage the clutch and swing the lever from the 'RUN'
position to 'REW' position. Do not force the lever if it
does not swing easily, but turn the hand setting knob
slightly to disengage the gear.
Move lower take-up belt on to idler pulley which is
the pulley farthest away from the take-up arm.
Switch on the motor until it gains speed, then release
the clutch, and the film will be rewound rapidly.
Immediately after rewinding, and before removing the
loaded spool, change the lever to 'run' position.
The table of Projected Picture Sizes Obtained with
Various Projection Lenses has been captured as a scanned
image. It can be found on the Main
Pictures and Table page.
Maintenance of Model 613
Before every show, and at any other time that appears
necessary, the projection lens and both condensers should
be cleaned. Use lens cleaning tissue. The projection lens
is removed merely by pulling it forward by the outer lens
barrel. The front and rear elements are then accessible
If only a slight amount of dust has accumulated on
these lenses merely use lens cleaning tissue to remove
the dust. The greatest care must be taken when cleaning
bloomed lenses to avoid scratching or rubbing the
surfaces. Dust may be removed with a soft camel-hair
brush applied very lightly and carefully or alternatively
lens cleaning tissue may be used with equal care. The
same treatment should be given the Magnilite condenser,
and the main condenser which are removed from the
projector by pulling on the holder handles.
Preparatory to cleaning the aperture open the film
gate, remove the lens, and the removable gate shoe. To
remove the gate shoe, grasp the metal and withdraw.
Use no tools.
Clean and polish with a soft cloth. If dirt or
emulsion has gathered and hardened on the shoe, remove by
rubbing with a soft dampened cloth to avoid scratching
the polished surface. Use no tools. To clean the
aperture insert the brush supplied with the projector
through the opening, being careful to stop forward motion
of the brush at first sign of contact with the condenser
lens. Slowly withdraw brush, turning it in a clockwise
and counter-clockwise direction to remove dust and dirt.
Clean the film channel by opening the gate and inserting
the brush into the channel in a vertical position. With
the gate partially closed, move the brush up and down to
remove all dirt and emulsion. The machine must not be
running. When replacing the gate shoe, be sure that the
guides are placed in the grooves formed by the metal
plate attached to the back of the lens casing. An audible
click will be heard when the metal frame is correctly
The main oil cup should receive one drop of oil after
each 8 hours of operation. The other oil cups should
receive one drop of oil after every 32 hours of
operation. The sprockets should be saturated with oil
every six months. To saturate these felts, have the
projector disconnected from the line and lay it on its
side. Insert the tip of the oil can into the holes and
press the button of the oil can about three times.
"The feed and take-up spool arm spindle bearings
require no attention, as they are a special,
To replace the projector lamp, unscrew the cap at the
bottom of the lamphouse and allow the lamp to slide out
into the hands. It may be necessary for you to tip the
projector slightly. If a projector lamp is being replaced
during the show, be careful as the lamp slides down to
grasp it by the relatively cool centring ring. This
operation should be performed quickly since a moment or
two after the lamp is disengaged from the socket, the
centring ring, acting as a cooling flange, becomes quite
warm. If the lamp does not readily drop out, insert the
blunt end of a pencil through the top of the lamphouse
and rock the lamp until it is dislodged.
Insert the new lamp with the vertical tongue on the
centring ring toward the front of the projector and
revolve it slightly one way or the other until the tongue
settles into the centring slot in the bottom of the
lamphouse. Replace the screw cap, making sure that it
screws in squarely and tightly to lock the lamp in the
Before attempting to change a lamp, disconnect the
mains lead from the wall socket.
Since the lamps are designed to burn base down, the
machine must not be turned upside down, or laid on its
side while the lamp is burning.
The reflector is permanently adjusted at the factory
and no further adjustments should be attempted.
Occasionally it is desirable to polish this reflector in
the same manner as the projection lens or the Magnilite
condensor. The reflector is removed by turning the holder
counter-clockwise. Polish carefully and replace.
Unscrew the metal cover turnng it counter-clockwise.
Unscrew the lamp and replace it with another and put the
cover on again.
Examine the motor brushes occasionally and replace
them when the body wears down to about a quarter of an
inch. To replace, remove the two screws MB (see Main
Pictures, Figure 5), which will release the springs
to which the brushes are attached. If the brushes are not
worn too short to continue using them, clean the ends and
replace, being sure that the concave contact surface of
each brush is so inserted through the square hole that is
will fit the curve of the commutator.
There are three belts fitted to your projector and
their functions are as follows:-
- Take-up which is the longest of the
- Re-wind which is shorter than the take-up belt but
of approximately the same diameter
- Reverse which is the shortest belt of the three
and of reduced diameter
The replacement of belts should be undertaken as
Take-up. Thread the belt with a twisting action
through the front of the slot in the take-up bracket
until the end of the belt comes out of the back of the
slot. Fold the take-up arm to shorten the belt path and
pass the end of the belt which comes from the front of
the slot over the top of the pulley and under the guard.
Hook the ends together and close the loops together with
a small pair of pliers.
Rewind. Thread the belt with a twisting action
through the front of the slot nearest the re-wind/run
lever until the end comes out of the rear slot. Fold the
upper arm to shorten the belt path. Pass the end of the
belt which comes from the rear slot over the top of the
re-wind pulley, under the guard, and join as for
Reverse. Thread the belt with a twisting motion
through the short square slot at the front of the
projector until the end comes out of the rear slot. Pass
the belt over the top of the reverse pulley and under the
guard. Join as for take-up.
- Oil your projector in accordance with
- Set your AC/DC switch for correct current
- Leave your machine set in the 'forward'
- Leave your re-wind/run lever in the 'run'
- Make sure your belts are on the correct
- Leave your speed control knob unscrewed two or
three turns when the show is finished
- Make sure that the lamp lock screw is tight
- Keep all your lenses clean
- Keep all film contact surfaces clean
- Check for bent spools
- Check your voltage
- Move the machine while the lamp is hot
- Clean your projector whilst it is running
- Re-wind or repair a hired film
- Reverse the direction without disengaging the
- Operate run/re-wind lever without disengaging the
- Replace lamps unless mains are diconnected.
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