Film-Tech Forum ARCHIVE: Setting phase with Cat No. 69 Test film loop

This is topic Setting phase with Cat No. 69 Test film loop in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Marin Zorica (Member # 1716) on 01-08-2006, 10:12 AM:

Today i was aligned one both and when i set phase with oscilloscope and Cat 69p test film i get good result on screen , but slit image on film isn't parallel with film, but one side is little down.

may bee you didn't understand me and this is picture of what i got when i set phase:

On picture i think wright position would be number 1, but then phase isn't good, and when i set phase to bee good i get slit positioned like on mark 2!

This happens on both projector, and sound is OK, no distortion or any kind of other difficulties.

Is this is ok, or i missed something?

Posted by Christos Mitsakis (Member # 143) on 01-08-2006, 11:27 AM:

Marin,
Are you using a cinema processor with proper preamplifier, or a console or another substitude in the position of the preamp?
Is it possible that the cell wiring is out of phase?
Before your alignement did you check for same level in the two channels?

Posted by Marin Zorica (Member # 1716) on 01-08-2006, 04:30 PM:

Yes first i set level with 69T tone loop, then i set phase!

No, cell is directly wired to processor!

OK, it isn't unparalleled like is on picture, but slit just little bit goes down at one side.

Correct me if i'm wrong, does when we do this sound may be distorted? Mine isn't so may bee this is wright to do, i repeat is same situation on both machines, because if i may bee do something wrong at one i think i can do at other same mistake.

Projectors are Polish Prexer AP-61.

Posted by Marin Zorica (Member # 1716) on 01-10-2006, 10:01 AM:

No other ideas or opinions??

Is this wright what i align?

Posted by Brad Miller (Member # 2) on 01-10-2006, 10:50 AM:

Set the alignment using the oscilloscope and forget what you see. Play a reel of A or SR analog film with lots of dialogue and not much other sound and verify it appears to be coming out of the center channel and not the surrounds. That would be correct.

Posted by Marin Zorica (Member # 1716) on 01-10-2006, 03:33 PM:

quote: Brad Miller
Play a reel of A or SR analog film with lots of dialogue and not much other sound and verify it appears to be coming out of the center channel and not the surrounds

Yes I know about this method, but problem isn't align because i align system good, but this screen doesn't have surround, but it have L C R speakers and when i align reader first i noticed is that i hear much dialogue from center, and center channel level is higher now.

But mine point is why slit image on film is little angled, little strange to me, but it works...