8mm Forum: ST-1200HD M & O question

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Topic: ST-1200HD M & O question

Akshay Nanjangud
Jedi Master Film Handler

Posts: 637
From: Dallas, TX
Registered: Nov 2011

posted September 15, 2012 12:37 PM

I dont have any optical sound films, so am unable to test with film. Please help, I have two questions.

1. When In optical sound mode, is the magnetic sound head supposed to come down and make contact with the film? This is what happens in magnetic sound mode and I feel something different should happen in O mode.

2. The sound when I play M mode is excellent. Having no optical sound film to test, can we guess or check to some probability if the optical sound work too? I hear a hiss from the speaker in both M and O modes.

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Pasquale DAlessio
Film God

Posts: 3523
From: Bristol,RI, USA
Registered: May 2010

posted September 15, 2012 01:16 PM

More than likely if the magnetic sound works so does the optical. Ask John Capazzo he has one.

PatD

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Hugh Thompson Scott
Film God

Posts: 3063
From: Gt. Clifton,Cumbria,England
Registered: Jan 2012

posted September 15, 2012 01:21 PM

Akshay,if you put a sliver of paper or a paintbrush in between
the receptor and the lens,you'll hear the noise it creates on the
speaker, which tells you that the optical sound works.

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Akshay Nanjangud
Jedi Master Film Handler

Posts: 637
From: Dallas, TX
Registered: Nov 2011

posted September 15, 2012 02:00 PM

Thanks guys. Hugh, I did do what you said and I heard clicks when I slid paper. So, it seems fine.

Again, my other question was the magnetic sound coming down and engaging in O mode. Is this normal?

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Winbert Hutahaean
Film God

Posts: 5468
From: Nouméa, New Caledonia
Registered: Jun 2003

posted September 15, 2012 02:07 PM

Akhsay, if you want for a test purpose, I can send you a roll of optical print from a film made in 1985 for free as long as you pay for postage.

Email me for your address.

--------------------
Winbert

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Akshay Nanjangud
Jedi Master Film Handler

Posts: 637
From: Dallas, TX
Registered: Nov 2011

posted September 15, 2012 02:19 PM

Thanks, Winbert. I sent you an e-mail.

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Hugh Thompson Scott
Film God

Posts: 3063
From: Gt. Clifton,Cumbria,England
Registered: Jan 2012

posted September 15, 2012 03:08 PM

No Akshay,their should be no mag signal if you have it in Opt.
there could be a bad connection on your switch.I'm sure that
someone on here with more knowledge on electrics than myself
will be able to give some advice.

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Rob Young.
Phenomenal Film Handler

Posts: 1633
From: Cheshire, U.K.
Registered: Dec 2003

posted September 15, 2012 03:36 PM

I think Akshay means that in optical position the mag sound pressure guides still move down into place?

This is normal with the ST1200HD

You should see the first of the 2 lower rubber rollers slightly alter position when switching to optical (it moves back slightly).

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Akshay Nanjangud
Jedi Master Film Handler

Posts: 637
From: Dallas, TX
Registered: Nov 2011

posted September 15, 2012 04:59 PM

Rob, what you understood is exactly what I meant. The rubber rollers do alter position like you say. Things look okay for now.

On a similar note, what do you all do with a new projector before running the more valuable films? Of course, the cleaning, lubricating drill is standard. After this I run the same 400' of film a few times, look to see if the film is developing scratches with more runs, see that the sound is satisfactory. If the projector passes these tests, I play my favorite films. Is this correct?

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Andrew Woodcock
Film God

Posts: 7477
From: Manchester Uk
Registered: Aug 2012

posted September 15, 2012 07:10 PM

All magnetic sound head assembly still engages the film path fully on all Elmo projectors when playing back Optical sound films. The switch is obviously moved from mag to opt but without the Mag sound heads engaged the optical soundtrack will sound poor ie main switch position 1. This is due to the effect the rollers have on smothing the films path as they pass through either of the sound heads or the Silicon Photo Diode.Hope this helps

--------------------
"C'mon Baggy..Get with the beat"

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Akshay Nanjangud
Jedi Master Film Handler

Posts: 637
From: Dallas, TX
Registered: Nov 2011

posted September 15, 2012 07:41 PM

Thanks, Andrew. Once Rob said the pressure guides (now that I know what to call it) do engage I had an inkling the reason would be what you gave. Now that am sure the pressure guides do move down, I feel better.

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Rob Young.
Phenomenal Film Handler

Posts: 1633
From: Cheshire, U.K.
Registered: Dec 2003

posted September 16, 2012 05:43 AM

Just to be technically accurate, it's the "Head Pressure Assembly" which moves down into place! [Smile]

Akshay, I think that sounds like as good a plan as any to test an unknown projector; I always check the film path before and after every reel, maybe giving it a blast with compressed air just to be sure it is clean.

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