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Author
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Topic: Eumig 938 Stereo Main Switch
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Paul Adsett
Film God
Posts: 5003
From: USA
Registered: Jun 2003
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posted December 13, 2014 04:21 PM
Halfway though a reel last night my Eumig 938 Stereo suddenly shut down without warning. At first I thought it was a power failure, or the plug had come loose, but this was not the case. The fact that the shutdown was accompanied by a smell of burnt plastic raised the alarm of a major disaster to my beloved 938. Using a multimeter it quickly became apparent that no voltage was getting to the transformer, and it became obvious that the culprit was that POWER ON-OFF sliding switch. Somehow it had burnt out. Fortunately I have an old Eumig 926GL which I keep for spares for the 938, so I replaced the main power harness from the 938 with the one on the 926. All is now well, and the 938 is back like new.
My question is, does anyone know of a source for that Eumig 900 series power switch? Is it a custom Eumig design, or can it be obtained from electronics suppliers?
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The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj
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Paul Adsett
Film God
Posts: 5003
From: USA
Registered: Jun 2003
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posted December 14, 2014 10:08 AM
Thanks for the compliment Janice, I am sure that this was a job that you would have had no difficulty with ![[Smile]](smile.gif) .
Actually, IMO those Eumig 900 series power slide switches are a very poor design. Over the years I have had several of them sieze up and refuse to move. I think there must be severe corrosion going on inside the contacts. I am thinking of installing a decent mains switch from Radio Shack, the ones with the built in light, on the rear face of the projector, there seems to be plenty of space inside the machine to do that.
Happy Chistmas Jan, and many good holiday screenings!
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The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj
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Paul Adsett
Film God
Posts: 5003
From: USA
Registered: Jun 2003
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posted December 14, 2014 12:14 PM
Hi Andrew,
Yes I think it will be a pretty easy job. There is sufficient space at the back of the machine to do it, and I think I will just have to drill a single hole thru the aluminum wall behind the transformer.
The 938 is a really great machine, I love mine, but it does not have the tank-like build quality of the GS1200. Eumig skimped on wall thicknesses of some of the plastic components, no doubt to save weight and cost, and I hate having to use a screwdriver to open up the lamp house to clean the gate ![[Frown]](frown.gif) . Why Eumig did not use 2 knurled knobs instead of a screwdriver head is just beyond me.
All showing that even "The Wizards Of Vienna" were not perfect.
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The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj
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Paul Adsett
Film God
Posts: 5003
From: USA
Registered: Jun 2003
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posted December 16, 2014 01:32 PM
Sometimes, not very often, when you are trying to fix a projector, you really luck out. In reference to fixing the mains switch on the 938 I have found what I believe to be an almost perfect retrofit sliding switch from Radio Shack. When I say almost, it means that there will need to be a minor modification to the switch, not the projector, which should be easy to do. The new switch looks substantially more robust than the OEM Eumig switch, and it switches very smoothly and very positively. I think it will be a huge improvement to the projector.
I plan on doing this project in the next couple of weeks, and will photo document the process. Stay tuned!
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The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj
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Paul Adsett
Film God
Posts: 5003
From: USA
Registered: Jun 2003
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posted December 22, 2014 01:29 PM
Thanks Guy's. As you know, it is very satisfying to repair a projector and bring it back to a fully workable machine. In this case, as I said above, I stole the harness out of the 926 when the sliding switch on my 938 failed. This left the 926 as a 'dead' machine, but now it is back to full working condition. The challenge of totally incorporating a replacement sliding switch into the Eumig's original position, and interfacing with the mechanical interlock mechanism remains a challenge for the future! In the meantime though, I really like that rocker switch, and it does look and feel right at home on the 926.
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The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj
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Paul Adsett
Film God
Posts: 5003
From: USA
Registered: Jun 2003
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posted December 22, 2014 03:54 PM
Andrew has hit the weak points of the 926GL Stereo. An otherwise superb machine marred by two very bad decisions by the Eumig designers (or perhaps more likely, their marketing bean counters):
1. The coaxial reel arrangement, which is a pain to thread up as the take up reel is blocked by the supply reel. And the film has to go though a sideways displacement and twist before it enters the gate.
2. No feed sprocket. That's right, Eumig elected to do away with a feed sprocket on the 900 to 929 series machines. And you would never know it from the picture on the screen, which is absolutely rock steady - as long as you do not go bigger than a 400ft supply reel. If you try to run a 600ft reel, the film will jerk off the supply spool and noisly thrash around somewhere between 500 and 600ft, and the picture will become very unsteady and start slipping in the gate.
Despite all this, I have never scratched a frame of film on a 926.
The 'Optical Levelling' system works great, but the lens quality is poor, lacking contrast.
On the plus side, the sound mechanics and stereo electronics are just superb, and you can get really stunning mono and stereo from these machines. So as Andrew correctly point out, they make great recording machines, particularly with the comprehensive mixing controls which are far better and easier to use than the GS1200.
So the 926GL really is a mixed bag. I can certainly recommend it though for use up to 400ft reels, if you can find a better lens.
All the faults of the 926 were corrected on the later models, which reverted to a conventional 2-sprocket in-line film path. The top of the line 938 and 940 had 800 ft spool capacity and 150 watt lighting.
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The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj
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Paul Adsett
Film God
Posts: 5003
From: USA
Registered: Jun 2003
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posted December 22, 2014 08:03 PM
Andrew, I feel that the omission of the feed sprocket is by far the greatest sin on the 926GL. The coaxial reel arrangement, although a nuisance, a bit strange, and a totally unnecessary arrangement, is not in any way responsible for the inability of the 926GL to be able to smoothly handle large spools. That all comes down to no top sprocket, and had there been one the coaxial arrangement would have been as smooth running as any conventional in-line reel arrangement. A top sprocket would have made all the difference on this machine.
quote:
Your new switch will last forever
Or at least Graham until the sound head wears out! ![[Big Grin]](biggrin.gif)
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The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj
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Paul Adsett
Film God
Posts: 5003
From: USA
Registered: Jun 2003
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posted December 24, 2014 02:24 PM
Yes I totally agree Andrew. It is hard to believe that elimination of a top feed sprocket (and its associated gearing) would save a significant amount of money to the manufacturer. I have yet to see a sprocketless projector that is not really fussy about the mechanical properties of the film (thickness, flexibility, and friction) as well as reel size. A classic example is the Pathe Super Baby and Pathe Ace, both totally sprocketless projector, but one which Pathe had to use flapping rollers with brake arms on both the feed spool and take up spool, in order for it to be able to take decent sized reels. Even with these features, the Baby and Ace claws will often skip frames as the reels tug on the film. All of which could have been avoided by two simple sprockets geared to the drive shaft.
--------------------
The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj
| IP: Logged
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