Gem Conversions
9.5ers (and the 16mm lot) were offered (at least) two different optical sound conversions for the Gem, the ACE and the Cinesmith. As far as I can make out,hese two were fairly successful and finally prompted Pathescope to introduce both the Aurator add-on unit for the Gem and, of course, the Son (ugh!).
I do have a curious machine that looks like a home conversion of a Gem. The problem, as so often, is that clever design is marred by clumsy execution. The alterations have been left crude round the edges, and no amount of hammer finish can disguise the fact that hand painting is just scruffy. In fact, it does work and delivers reasonable sound, but only if firm pressure is applied to the pinch roller that holds the film to the sound drum.
Here is an ad for the Aurator and extracts from a Pathescope catlog (the whole catlog can be found under Gear). I (Sep 08) acquired an actual Aurator, tho' it is a 16mm version. As will become apparent, it probably differed from the 9.5 version only in rollers and mag head. I will get it to do a strip-tease for you.
The speaker is in the lid. Take it off, and you get the machine more or less ready to operate. What is missing here is a vertical arm attached to the soundhead unit, carrying four guide rollers (one sprung, I think). You can see it if you zoom in on the threading chart. Then we have a chitterling pic with soundhead removed. It couples to the amp via a single connecting plug. To me, the whole thing has an air of being cobbled together as cheaply and quickly as possible, not an unfamiliar Pathé trait. The case is entirely plywood, covered in a sort of leatherette. The bedplate for the projector, the soundhead cover and the soundhead itself are held in place by woodscrews into the edges of the plywood - a recipe for early failure if ever I saw one. What is not apparent from these pix is that there was a mains lead emerging from a rubber grommet on the bottom left of the control panel, which connects thru to a Bulgin plug at the back to provide a power supply to the projector. This example has been modified slightly so that the Bulgin provides power to the unit, leaving the projector to find its own mains connection.
Pic 4 above is the main backing plate for the soundhead. In pic 5, clockwise from top left, we have the sound roller bearing which fits to the back of the plate, then the spindle that carries the sound drum itself. The flywheel fits to the back of this. Next is a solid large roller, which presumably imparts some damping. It also should carry a strobe disc, which I do not got, which is lit by a lamp in the amp thru the little window in the left edge of the plate. Finally, we have the sprung roller and its arm that holds the film against the sound drum. You can see why I think there is little difference between 9.5 and 16 models. I think the unit takes the film from below the gate to the right-hand side of the soundhead then back out to the lower side of the sprocket. But I am open to correction on this and would in any event be grateful for a copy of the Instructions and, of course, for my missing parts.
Here is an article about another Gem conversion I have copied from Mike Trickett in Oz, by his consent. (These pix do not enlarge, btw.) See the original, and more, at www.reeldeals.com.au.
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A PAST ARTICLE FROM REEL DEALS - The Aussie Magazine for Film Collectors The Klee Sound attachment for the Pathescope Gem 9.5mm Projector. |
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In 1932, Kodak introduced a sound version of their 16mm gauge. Pathfollowed suit, and their 9.5mm sound on film system appeared in 1934. A range of sound films and their first sound projector; the Vox (Latin for voice), appeared. Amongst their mainly British B features and shorts, by arrangement with Paramount Pictures, Pathreleased onto 9.5mm sound a range of the immensely popular Betty Boop and Popeye cartoons.
Pathescope Gem on Klee Sound sound adaptor
Path produced two more sound-on-film projectors after the war, the Pax in 1949 and the Son in 1951. The Son was basically a Gem with an extended chassis containing the sound section. These projectors all utilising photocells and valves for amplification were quite expensive, and in many cases beyond the pockets of would be home showmen. In the early 1950s, here in Australia, an enterprising engineer in the employ of Home Cinemas, the Melbourne distributors of Pathproducts, designed an add-on attachment for the popular Gem 9.5mm silent projector.
This unit took the form of a base containing an amplifier and the necessary optical train torecover the sound from the tiny optical sound track on the 9.5mm film. The rotary stabiliser and scanning system were based on the Pax design. The engineer was Alan Kleeberg, and the unit became known as the Klee Sound Adaptor. Close-up of Sound Head It is not known how many of these ingenious devices were manufactured, but estimates put the number in excess of 50.
For many of us in the Australia of today, where virtually no domestic electronic equipment is produced, the manufacture of such a specialised piece of equipment would seem all but impossible. Prior to the early 1980s, Australia had a very active radio and television manufacturing industry. With this background, and the availability of locally manufactured components, the production of this unit went ahead.
The Klee Sound appears to have been manufactured from all Australian made parts, and used the following valve line up. 927 PE Cell, 6J7 Preamplifier, 6SJ7 Intermediate Amplifier, 6L6G Output and a 5Y3GT Rectifier. The speaker was a 10-inch Rola model 10G, which was mounted in the combined carry casespeaker box.
Under view of Klee Sound Unit The overall construction of the unit is very good, even the amplifier sub-chassis is rubber mounted to eliminate vibrations from the projector motor.
In operation, the unit performs well. The biggest single drawback is the variable speed of the Pathescope Gem projector. A strobe disc was mounted on the main sprocket to assist with speed adjustment. The need for the projector to be located close to the sound head (due to the spacing between sound and image on the film) the motor and lamp switches are difficult to access. However, a projector power (both motor and lamp) switch is incorporated into the control panel of the Klee Sound unit.
From the above illustration, it will be seen that the exciter lens is located within a locking sleeve mounted on the deck. The light slit is projected upwards onto the tiny sound track from the exciter lamp mounted under the deck plate. The exciter lamp is a 6 volt tail light type globe, fed by AC. The hum, which would normally occur when AC is used on an exciter lamp, is all but eliminated by the use of a high current filament, relying on the thermal inertia effect of the photoelectric cell, located in the vertical cylinder at the bottom of the illustration. 9.5mm optical sound film
Copyright 2002 Mike Trickett. Geelong, Australia |
The unit was supplied in a sturdy carry case, which incorporated the speaker, and had sufficient room to carry both the Klee Sound Adaptor, as well as the Pathescope Gem projector.
Read on for 200B sound conversions.