Bell & Howell 179 Model E

This fully enclosed machine has external spindle arms which are located by small guidepins and held in place by thumbscrews. When not in use the front arm is stored inside the rear of the case, and the rear arm is nestled into a holding block on the inside of the main door. The springbelts are then pushed in through the case openings to lounge where they might (be careful that the front one isn't allowed to contact the lens!)

That main door also has mounting points for a spare rear springbelt, a box of fuses, a small dust brush, a card with a threading diagram, and an official Bell and Howell "Filmo" oilcan. I don't know what the character of the original oil was, and I used to refill that can with sewing machine oil, but a recent acquaintance of mine who collects projectors said that 20W engine oil should be used. Sounds OK to me.

The speaker case has a door in the back which opens to reveal (besides the driver element) a storage compartment for cables, etc. Also, there are clips on the inside of the door for mounting a take-up reel for storage.

A spare front spring belt is not provided, since it's only used for reverse projection take-up and is not necessary for rewind. Reverse projection is accomplished by merely running the motor backwards via the forward/reverse switch. To rewind, the reels must be swapped, the forward/reverse switch must be in "forward", and the rewind gear on the rear arm must be engaged. This last step changes the rear arm spindle from slipping forward rotation to (hopefully) solid backwards rotation.

The machine has a clutch, which allows running of the motor to cool the lamp without moving the film. Caution should probably be used in regard to doing this for long periods while film is threaded, because the rear reel wants to turn any time the motor is running, and preventing it from turning may cause uneven wear of the flat slipbelt. This is especially true ifdone near the end of a show when the reel is heavy with film and is pulling down hard on the belt.

The projection lamp socket requires a lampbase with an indexing ring. It is inserted from underneath and a bottom end cap with contacts in it is screwed in place to secure it. I've used a 750-watt DEJ and a 1000-watt DFY in mine. The lamphouse has a metal warning plaque near the top which gives 1000 watts as the maximum allowable lamp power. The sound exciterlamp is a 4-volt, 0.075-amp BRD.

The vacuum-tube "Opti-onics" amplifier uses a power transformer and a 5Y3GT full wave rectifier for the DC supply. I believe that mine is an "early" model. I've seen "later" ones that have no transformer, where the (higher voltage) tube filaments are in series across the AC line, and the rectification is by means of solid-state diodes.

The amplifier has a 1/4" microphone input recepticle and two speaker output jacks. The primary one takes a 16-ohm driver, and the second one is for an 8-ohm driver. It is labeled "Dual", meaning two 16-ohm'ers may be connected in parallel. There is no internal speaker in this model (at least, not of this vintage, which is unknown).

The lens in a 2-inch "Excessalite".

The pull-down mechanism consists of a two-finger claw and a single blade shutter. Due to the peculiarities of the design, the shutter turns three revolutions and the claw travels up and down six strokes for every frame of film advancement. The claw is retracted for five of those strokes and emerges from its slot for the sixth. The up-down cam is on a separate shaft from the in-out cam, and spins at three times the speed, carrying the shutter with it. This permits the use of a more gradual slope while still keeping a rapid stroke. I assume the designers decided that this will stand up better against wear.The removable gate piece is clipped to the rear of the lens housing. This lens housing slides forward to allow threading the film, and backwards to close the gate for running. There is a lever at the front of the machine for setting this. Gate pressure is adjustable by rotating the offset bearing of the pivot point for this lever and re-tightening the bearing lockscrew.