Informations about YELCO P111-Q or PHOTAX multi-8 or Ifba Quartz

[Pat Grossard]

Hello everybody,
I've just changed the two belts and tried the projector and it works well.
The only small problem is that the image is very dark. So I took apart the optical part and cleaned the lenses.
Then I noticed that there is a small glass window in the middle of a system and it is dirty and cracked vertically.
1) I don't know how to remove it from the system to clean it
2) is it normal that it is cracked?
I'm attaching photos
Thanks for your answers

[Joerg Polzfusz]

Such pieces of glass are normally used to protect the film from the heat produced by the lamp.
The „crack“ looks too straight to me to be not made in the factory - could this be something like an expansion joint?
Unfortunately, I haven’t got a clue about how to replace/clean the glass.

[Steve Klare]

My son has one of these: I gave it to him when he was 12 years old. I borrowed it a few minutes today to try this out.

In Pat's picture "View of Proj_2" , almost exactly in the center of the picture is a sliding control that puts the machine in and out of single-frame mode. When I operate this slider and shine a light through the gate, I can see the heat shield move up and down, into and out of the gate.

[Tom Dennis]

The "crack" on the heat shied is just an expasion device so that the heat shield does not shatter when hot i.e. the unit is in 2 halves. This is quite normal on projectors, because it is before the optical system it does not show on screen, on slide projectors having condenser opotics even a cracked condenser does not normaly show.
I think Steve is on the right track.
Have you tried Van Eck for a book? he lists a reasonable priced download.

[Pat Grossard]

hi everybody
many thanks for your responses.
In fact as U can see on the photos, there is a 8-S8 controler, when it is UP it's Super 8 mode film and when it's down it's 8 mode film. But there is no way to remove this to access the heater screen glass.
So I tried to clean the glass carefully with a cotton swab soaked in water.
I'll try viewing again this afternoon.
I keep U informed ....
Have a good day friends
Pat

[Pat Grossard]

Also I'll contact Van Eck to see if they have a tip to remove the glass shield.
Pat

[Tom Dennis]

Are you removing the heat shield to clean then replace? If so then thats O.K. the purpose of this unit is to protect the film from being burnt from the heat of the lamp, so projection of a film should not be attemted without the heat shield in place.

[Pat Grossard]

hello TOM,
I just want to remove it only to clean it. And then replace. The problem is that I don't know how to remove it. It seams a bit hard and complex because there is no simple way .... in fact I have to remove all the black support by removing 2 screws but very hard to extract, I have to extract a lot of parts .....
I think just clean it as it is with a cotton swab.
Thanks a lot

[Nantawat Kittiwarakul]

Seems like there had to be a major teardown in order to gain complete acess to that glass heat filter. I won't be surprise if it's necessary to remove the entire film gate ass'y out of the main casting and disassemble tons of parts to reach it. In fact it seems almost like it's designed to be (almost) unserviceable in the first place.

[John Burgess]

I’ve been interested in reading about your problem Pat. As I understand it so far the filter is used only for still frames , to stop the frame in the gate from burning! It seems to me that this glass filter is not moving out of the way to allow the full light from the bulb. I’ve never owned one of these projectors ,but the last thing you need is a filter blocking the light from the gate unless still framing.Please correct me if I’m wrong. Good luck anyway.
John

[Tom Dennis]

Good morning Pat,
Been giving your problem some thought and reading Steve`s post I take it that this is on the single frame projection device. I remembered in the past working on a PHOTAX P111-Q my notes from way back just say mechanism SIMILAR to Sankyo Dualux 8 [the early models].
However cleaning in situ is by far the best option as heat shields can get brittle with age and use, these are tempered glass and even a little knock will cause them to shatter.
Thoughts on lack of light, the lamp is a diochric unit, with age these suffer from the reflector silvering oxidising reducing the output considerably [does the silvering on the inside of the lamp look nice and bright?] Also check the lamp for a small dark blob on the inside of the lamp glass, I have seen this occur and it is hardly noticeable but reduces the lamp output considerably.

regards Tom

[Pat Grossard]

Finally I managed to clean the screen glass.
I also disassembled and cleaned the optics and lenses.
Everything is ok now.
I projected a few films and I saw the difference, it is much clearer now.
I will order another lamp from Van Eck and the projector will be like new .... well almost
Thanks for all your messages and advice.
Have a good day.
Kind regards