8mm Forum: Another pulse-sync question!

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Posted by Sam James (Member # 477) on May 23, 2006, 03:06 PM:

When, in December 2005, I bought an ST-1200 in favour of a twice the price GS-1200, one of the compromises I knew I'd be making was the inability of the ST to record pulse-sync sound. As I regularly use my camera which is capable of producing both a pulse tone and a pilot tone, and I've recently bought a Nagra reel to reel which is also pulse enabled, the posibility of recording sound to a sound-striped film is getting closer.

The next step ought to be for me to upgrade to a GS, buy a gadget or two from Pedro and, hopefully, Bob will be my uncle, providing I can work out how to link it all up.

BUT WAIT!!!

Whilst aimlessly leafing through my downloaded manual for the ST, I found a paragraph referring to the small jack at the front of the projector; something that, in my excitement at receiving the machine, I'd never bothered to investigate.
I quote:-
"The R-1 synchronizer is used to synchronize the Elmo SR-1 Cassette Recorder with the ST-1200HD projector for transferring sync-sound to magnetically striped film. The SR-1 Cassette Recorder, when attatched to Elmo cameras, 110R, 612R or 1018R, utilizes a pulse-sync system for recording sound in post-sync for later sound transfer to the film during projection."

Now, call me old fashioned, but that seems to be saying that there is a way for me to link up my Nagra to my ST and sync sound to picture. There are, apparently at least 554 of you out there so hopefully someone will haved some ideas/suggestions/abuse to send my way?

Sam

Posted by Kevin Faulkner (Member # 6) on May 23, 2006, 04:31 PM:

Sam, for once I have to say that this is something I have not investigated either. What I can tell you is the the socket on the front of the ST is connected to a reed switch which closes once per frame. It does not do anything else other than that.

Now the way I think this works is as follows:
You connect the SR1 up to one of the cameras in question and the camera will supply one pulse per frame as you shoot your film and capture the sound on cassette.

After you get your film back from processing and striping you then connect the SR1 up to the ST with the tape at the first point of sound. The sound output is now connected to the input of the ST and the ST is put in the record mode. The SR1 is switched to be controlled by the ST, and the ST is then started. The closing of the contacts once per frame now controls the tape and keeps it in sync with the ST. Basically the SR1 is now controlling the speed of the tape to match the recorded pulses with the pulses from the ST.

Hope that makes sense and I'm sure that someone who has actually used this system will probably come forward with some more detailed info.

Kev.

Posted by Sam James (Member # 477) on May 24, 2006, 11:14 AM:

Kev,
Absolutely it makes sense, but I thought that only the GS was capable of being controlled by an external pulsed gadget or resolver. If my ST can do the same then happy days are here again, providing that is, I can find an R-1 synchroniser. Anyone out there got one to sell?
Sam

Posted by Joerg Polzfusz (Member # 602) on May 24, 2006, 12:00 PM:

If I understood Kevin correctly, the ST-projector will always be the "master" and the recorder the "slave" in this setup. = IMHO there's no word that the ST-projector is capable of being controlled by an external pulsed gadget or resolver?!

Posted by Joerg Niggemann (Member # 611) on May 24, 2006, 01:32 PM:

Hi, the ST isn't capable of being controlled externally. The speed of its AC motor is determined by the mains frequency (50/60 Hz) and cannot be changed. The front connector (reed switch) can be used to provide information about the current projector speed to external devices which will then be able to sync to the ST.

Jörg

Posted by Sam James (Member # 477) on May 24, 2006, 04:46 PM:

So, given that my reel to reel has recorded location sound and a pulse/per frame signal, how do I get it to communicate with the ST in order to sync up with the image filmed by the pulse emitting camera?
Sam

Posted by Kevin Faulkner (Member # 6) on May 24, 2006, 04:52 PM:

Hi Sam, I think that where the ST is concerned you have to use the SR1 or one of the other Elmo recorders. The ST is fixed speed and due to the AC motor ( as Joerg explained above) cant be varied its the recorder which has to vary in this case. This is where the GS scored as it does it the right way round ie the pulses on tape control the projector.

To be quite honest with you the setup with the ST was a bit primitive in this respect [Frown]

Kev.

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