21-09-2019, 08:12 PM
Sync pulses!
I don't think the Vitaphone system used anything so advanced!
However, thinking of the problems that lack of sync could cause, and bearing in mind that the disc was driven from the motor that moved the film through the gate so that the two were locked together, I wonder if a 'pip' or something similar was recorded on the disc coincident with the 6 second film run in.
Moving the disc back and forth under the pick-up after the film run-in had been set would have been no different to the method used to preset the start point of discs in broadcasting.
Thinking about that reminds me of, I think, my second visit to the Earls Court Radio Show in 1959. A superb demonstration on the BBC stand involving four turntables, a rack of discs and one operator who, live, presented a high speed history in sound of the 1930s, 40s and 50s. The discs literally flew on to and off the turntables at breakneck speed with not one hiccup throughout the whole performance. As she was literally no more than a foot from the front of the watching crowd, I wonder if she found it more nerve wracking that doing it in the peaceful surroundings of Broadcasting House.
I don't think the Vitaphone system used anything so advanced!
However, thinking of the problems that lack of sync could cause, and bearing in mind that the disc was driven from the motor that moved the film through the gate so that the two were locked together, I wonder if a 'pip' or something similar was recorded on the disc coincident with the 6 second film run in.
Moving the disc back and forth under the pick-up after the film run-in had been set would have been no different to the method used to preset the start point of discs in broadcasting.
Thinking about that reminds me of, I think, my second visit to the Earls Court Radio Show in 1959. A superb demonstration on the BBC stand involving four turntables, a rack of discs and one operator who, live, presented a high speed history in sound of the 1930s, 40s and 50s. The discs literally flew on to and off the turntables at breakneck speed with not one hiccup throughout the whole performance. As she was literally no more than a foot from the front of the watching crowd, I wonder if she found it more nerve wracking that doing it in the peaceful surroundings of Broadcasting House.
