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A theater I worked at had an old RCA 35/70 magnetic sound system installed in 1961 for, "West Side Story." In this setup, they put two electrical boxes, one above the other, on the left side of the booth on the front wall. Each box had a long steel rod with levers on it that went across the front wall of the booth, just above the port windows. One box controlled the volume, and the other did the mag sound changover. So, there was only one electrical control that could be operated from either projector. If you wanted to make a mag c/o, you would put your foot on a floor pedal and your right hand on the lever above your head and spin it up (for #1) or down (for #2.)

There was a third box high up on the wall that was the high voltage power supply for the amplifier tubes in the racks below. All these boxes had "MI-XXXXX" numbers on them.

The previous operator had told me that if you let the upper magazine door on projector 2 open all the way, it would touch one of the rods and cause a 60hz hum in the sound system. He said several Altec people had looked at it over the years, and could not fix it.

I started working there in 1978 or so and it looked like 18 years of various kinds of tape had been stuck to the door and the rod. There were bits of friction tape, duct tape, masking tape, transparent tape, with a strange gooey mess all around.

In 1980, after running, "SW: Empire" in 70mm, it was decided to twin the theater. All the RCA stuff was to be thrown out. The owners asked me to do a nice job removing it because they thought they would sell it (Ha-ha! They ended up paying someone a lot to haul it away.)

The first thing I did was get ready to remove the third power supply box. I opened it up and saw a terminal strip. One terminal was clearly labeled, "AC HOT" with a white wire connected to it. Next to it was, "NET" with a black wire.

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quote:

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Originally posted by Joe Redifer:
What makes you think that they'll EQ? Judging by the design and prioritization of the projection, I doubt they care too much for sound, either.

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Nahh.......

Dobly? We can't spend THAT kind of money after all we apent on our beautiful new balcony. Just take out that port glass and turn up the booth monitor.

I ran an old archive print (I forget which film it was, unfortunately) with lots of cement splices. The reels, six of them as I recall it, were not made up or anything. This was a five change-over show as is the routine where I work. So while one reel was rolling, I was rewinding the previous, edge-inspecting it with my fingers to locate any damage. These prints are often very fragile so inspecting them is a Very Good Thing To Do.

So anyway, I was rewinding and inspecting reel number five while reel six was rolling, when I suddenly felt the print to, well, lose shape and get narrower. I stopped and saw that between two cement splices, about thirty seconds of the reel had split into two 17.5 mm halves. The first splice was halfway broke, but the second was intact.

The really strange thing is that the projector had simply continued running the reel as if nothing had happened. The two halves (of which one was loose!) neatly wound themselves on the takeup. There was sound through the whole incident (I always keep the booth monitor on to spot any trouble as soon as possible). The image on the screen showed no problems, of course, since the split probably occured below the gate, perhaps on the intermittent. No strange sounds warning me that something was wrong came from the projector. No warnings, no symptoms, no nothing, so of course I didn't notice anything until rewinding.

It was a common problem for film to split length-wise when using some failsafe detectors. Usually, but not always, that projector has an automation system. I havn't seen it since the big move to polyster.

I've heard of several similar film splitting incidents before. It usually occurs with triacetate film, and the tear usually begins at a splice that partly broke. As you may know, the film is usually under constant tension in the soundhead, and this tension allows a tear to propagate down the center of the film strip, while the film is being supported and transported by the sprocket teeth on each side of the film. In many cases, the failsafe does not detect this tearing, since the film is still running over the sprockets and hasn't actually "broken" in a way that trips the failsafe sensor.

Obviously, the person who last showed the print didn't inspect the film for problems as they wound it back onto shipping reels. I suspect that it was at a theatre that wasn't using platters, and they just took up the print onto shipping reels during the last show, which is evidently when this tear happened. Obviously, the film exchange didn't inspect the print either.

Moral of the story is to ALWAYS inspect a print, feeling the edges with your fingers, before you project it. (As you did ). Even new prints can have a nicked edge or torn lab splice. Used prints are almost never inspected by the film exchange (the distributors refuse to pay for this optional service), so "caveat printor" .