8mm Forum: Tape Synch Projectors

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Posted by Paul Adsett (Member # 25) on January 14, 2010, 12:27 PM:

Just wondering if anyone here ever used one of the various projectors that offered sound synchronizing to a reel-to-reel tape recorder. These were quite popular in the mid 1950's before the advent of 8mm stripe, and there were quite a few of them around. Eumig had the Phonomat synchronizer which integrated very neatly to the little Eumig p8 projector so that it looked like it was part of the machine (later they did in fact integrate the whole thing with the Eumig P8 imperial). I had one of these and my recollection was that it worked very well indeed for adding commentary and music to home movies. Bolex had the Synchromat box which coupled to the Bolex M8 via a flexible cable, and Noris had a really neat projector with a cassette tape player integrated right into the back of the machine. And then there was the 'Dominus' British machine which had a projector on one side and a tape recorder on the other side of a central chassis.
Interesting devices!

Posted by Winbert Hutahaean (Member # 58) on January 14, 2010, 01:35 PM:

Paul, as we jsut talked about synchronizing GS 1200 with Pedro through crystal sync feature, how did those tapes work with the projector in synchronizing sound and picture? What will happen if the motor of projector was slightly drifting after several minutes of playing?

rgds,

Posted by Claus Harding (Member # 702) on January 14, 2010, 02:12 PM:

Now that I have the GS, I have been looking at using it with some form of sync, to run a separate music track to a silent feature, for instance.

My reel-to-reel has a center track for timecode, so any 'pulses' can be laid down there, preserving the two stereo tracks for music, but I have yet to decide what to do, re: a Pedro box or similar.

I just got a Nizo camera which will output sync pulses as well for field sound use, so the possibilities are good, but one step at a time: first I have to see the test film to make sure the camera runs well. I am toying with the idea of using my little hand-held Zoom digital field recorder for sound....

Between the above, I hope to come up with a sync solution at some point.

Claus.

Posted by Winbert Hutahaean (Member # 58) on January 14, 2010, 02:30 PM:

quote:
My reel-to-reel has a center track for timecode, so any 'pulses' can be laid down there

Claus, so the pulses work like "[pulse-1]....[pulse-2].....[pulse-3].....[pulse-etc]" recorded on both 8mm & tape, and when pulses on 8mm projector is slightly speeding up then the reel-to-reel machine will try to catch it up by increasing it speed to? (in order to synchronize it?)

cheers,

Posted by Claus Harding (Member # 702) on January 14, 2010, 03:04 PM:

Winbert,
With timecode (broadcast standard) that is the way it works, and that is where the synchronizer comes in, keeping an eye on both machines, so they stay 'locked' on the same code numbers.

With the Super-8 sync system (not timecode), I have yet to figure out what will work and what won't when it comes to doing it. I strongly suspect a Pedro box is in my future though...

Claus.

Posted by Winbert Hutahaean (Member # 58) on January 14, 2010, 04:33 PM:

quote:
With timecode (broadcast standard) that is the way it works, and that is where the synchronizer comes in, keeping an eye on both machines, so they stay 'locked' on the same code numbers.

So basically, Pedro is NOT a synchronous machine, isn't it ? Because it does only work to lock the GS1200's speed for constant fps.

So when the DVD's speed is increasing, there is nothing can be done by Pedro. And if this happens, the sound and picture will not be synchronize. Am I correct?

thanks

Posted by Claus Harding (Member # 702) on January 14, 2010, 04:49 PM:

I am not a 100 percent sure of whether the Pedro box does anything for the 'incoming' player (tape or otherwise); the box is supposed to hold the GS to its exact speed as chosen.
I have to read up more on this, to see how/if it matches up with the sync pulse my camera puts out, and how/if that can be incorporated with the Pedro.

Claus.

Posted by Kevin Faulkner (Member # 6) on January 14, 2010, 05:35 PM:

"So when the DVD's speed is increasing" this will not happen. The DVD contains the sync pulses for the TV system in use. If the DVD speed were to change this would cause the TV to loose sync etc. The DVD source is very accurate indeed as is Pedros sync box. All that remains then is for the GS to lock to these accurate pulses which it does in a form of closed locked loop. The projectors speed control board compares the pulses from the Pedro box with pulses generated by its internal circuitry and if the 2 pulses drift the projectors circuitry compensates by adjusting its speed internally to the motor until both are the same.
I hope this has explained this ok without going into too much depth on the workings of the ESS circuit in the GS.

Kev.

Posted by Bill Phelps (Member # 1431) on January 14, 2010, 05:51 PM:

Paul... I have always been curious about the Bell & Howell system from around 1969. I have 2 of the cameras (442) that work very nice, all the hook-up cables, the tape machine (that doesn't work) and no projector (for this system).

If I could track down the tape player and the projector I really want to give it a go. Are you familiar with this system?

Bill

Posted by Claus Harding (Member # 702) on January 14, 2010, 06:14 PM:

Kevin,
Thanks for that; that does help. The gist of my question then is:
With the Pedro box locking the speed of the projector based on the DVD, if I were to lay location sound over to a DVD and play it with the Pedro box, it would lock up the DVD to the GS, but I would still have to manually line them up at the correct start spot?
I presume this is how the post-sound striping with prints is done?

Thanks,
Claus.

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