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km987654
Joined: 25 Jul 2007
Posts: 2874
Location: Australia
TV/Projector: Barco BG809s
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| Posted: Thu May 10, 2012 7:25 am Post subject: Image Wobble and Focus Issue |
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Some may know that I put 9" 09MFX3 tubes and a barco 808s chassis together. I have some problems that are at least interesting.
1 There is an image wobble or shimmer, its contantly there and eventualy after a couple of hours running you have to shut down. It was suggested that heat might be a problem so I did install extra cooling but there is no difference. Its not bad to start with I know its there so I can see it but others may not but it does get worse as power on time increases.
2 The focus yokes need to be a long way back on the tube neck to get good focus. The further back you push the focus yoke the better the focus and right now the focus yokes are right up against the suppport bracket for the neck board and you get the impression that if you removed the bracket and pushed the yoke even further back focus would improve.
I have not had a lot of time to work through this but I am about to put some time into getting this right.
Any thoughts 
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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Thu May 10, 2012 8:51 am Post subject: |
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Where do the astig rings go??
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km987654
Joined: 25 Jul 2007
Posts: 2874
Location: Australia
TV/Projector: Barco BG809s
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| Posted: Thu May 10, 2012 9:31 am Post subject: |
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| CasetheCorvetteman wrote: | | Where do the astig rings go?? |
The astig rings are behind the bracket that hold the neck board.
Have a look at the below link it gives you a some idea of the neck board setup but the bracket attaches to the tube several inches beyond the neck board.
http://www.curtpalme.com/Barco808_Layout10.shtm
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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Fri May 11, 2012 2:01 am Post subject: |
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Gotcha, yeah i was starting to wonder how you were fitting them in.
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km987654
Joined: 25 Jul 2007
Posts: 2874
Location: Australia
TV/Projector: Barco BG809s
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| Posted: Fri May 11, 2012 2:06 am Post subject: |
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| CasetheCorvetteman wrote: | | Gotcha, yeah i was starting to wonder how you were fitting them in. |
How far back should the focus yokes be or is it just a case of where they work best!! I suppose I am trying to determine if there is an electronic problem causing the position of the focus yokes to be different to where they should be.
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Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
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| Posted: Fri May 11, 2012 2:37 am Post subject: |
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My guess is that your problems are related, and you have HV regulation issues. If the pix is pulsing slightly, I'll bet your HV splitter is arcing internally. I've seen that a few times lately for some reason. The fact that your focus is way off 50 is another indication. THe focus yoke location will affect where the electronic focus is, and it's normal in some sets for them to be right up against the main yoke or back at the astig magnets. As long as you're between 20 and 80, that really is OK, but ideally of course it should be between 40 and 60 on each tube.
Swapping splitters can shift the HV by a few hundred volts, and that will shift the electronic focus point.
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km987654
Joined: 25 Jul 2007
Posts: 2874
Location: Australia
TV/Projector: Barco BG809s
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| Posted: Fri May 11, 2012 6:47 am Post subject: |
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| Curt Palme wrote: | My guess is that your problems are related, and you have HV regulation issues. If the pix is pulsing slightly, I'll bet your HV splitter is arcing internally. I've seen that a few times lately for some reason. The fact that your focus is way off 50 is another indication. THe focus yoke location will affect where the electronic focus is, and it's normal in some sets for them to be right up against the main yoke or back at the astig magnets. As long as you're between 20 and 80, that really is OK, but ideally of course it should be between 40 and 60 on each tube.
Swapping splitters can shift the HV by a few hundred volts, and that will shift the electronic focus point. |
That actually makes sense to me so thanks. It would have to be the splitter I hate soldering that white wire. I have some splitters here so I will swap that out.
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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Fri May 11, 2012 9:23 am Post subject: |
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Cant you screw connector the white wire? I dont know what it is, so i cant comment either way.
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km987654
Joined: 25 Jul 2007
Posts: 2874
Location: Australia
TV/Projector: Barco BG809s
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| Posted: Fri May 11, 2012 9:27 am Post subject: |
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| CasetheCorvetteman wrote: | | Cant you screw connector the white wire? I dont know what it is, so i cant comment either way. |
Hi Case
Look at that link I put in earlier you will see the splitter in the lower image with the white wire attached Curt makes reference to it. It can be a bit tricky to solder but its OK really its just not a simple board change like almost any other part of the projector.
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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Fri May 11, 2012 10:24 am Post subject: |
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Oh ok, no worries
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km987654
Joined: 25 Jul 2007
Posts: 2874
Location: Australia
TV/Projector: Barco BG809s
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| Posted: Sat May 12, 2012 9:32 am Post subject: |
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| Curt Palme wrote: | My guess is that your problems are related, and you have HV regulation issues. If the pix is pulsing slightly, I'll bet your HV splitter is arcing internally. I've seen that a few times lately for some reason. The fact that your focus is way off 50 is another indication. THe focus yoke location will affect where the electronic focus is, and it's normal in some sets for them to be right up against the main yoke or back at the astig magnets. As long as you're between 20 and 80, that really is OK, but ideally of course it should be between 40 and 60 on each tube.
Swapping splitters can shift the HV by a few hundred volts, and that will shift the electronic focus point. |
Thanks Curt your advice was spot on.
I have changed out the splitter and its made a huge difference. The wobble has gone and now good focus is at about 50% on green and red. Blue does not seem to focus I know blue does not focus as well as red and green but it doesn't seem to change much at all when adjusting focus so how sharp should blue be?
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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Sat May 12, 2012 10:17 pm Post subject: |
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Curt's advice is almost always spot on!! 
I would expect blue to focus just as good on the tube face, mainly cause it does on all 4 of my CRT projectors here. What happens if you swap the focus connectors between blue and green?
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Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
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| Posted: Sat May 12, 2012 11:41 pm Post subject: |
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Strange how I've had a bunch of these splitters do that over the last 2 years or so. Drove me nuts the first time, as the quad sizzles usually when this happens. 4 quad, 3 EHT boards later.. what didn't I change?
You can try swapping the focus yoke leads between the green and blue tubes to see if it's the focus board, maybe the focus yoke, astig, or just normal.
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km987654
Joined: 25 Jul 2007
Posts: 2874
Location: Australia
TV/Projector: Barco BG809s
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| Posted: Sun May 13, 2012 3:24 am Post subject: |
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| Curt Palme wrote: | Strange how I've had a bunch of these splitters do that over the last 2 years or so. Drove me nuts the first time, as the quad sizzles usually when this happens. 4 quad, 3 EHT boards later.. what didn't I change?
You can try swapping the focus yoke leads between the green and blue tubes to see if it's the focus board, maybe the focus yoke, astig, or just normal. |
I hear what you are saying I didn't check that because there didn't seem any reason to. There certainly was no arcing that you could hear.
I will swap the focus coil connections and see what that does.
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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Mon May 14, 2012 3:24 am Post subject: |
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You couldnt hear it cause the fans were too loud
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km987654
Joined: 25 Jul 2007
Posts: 2874
Location: Australia
TV/Projector: Barco BG809s
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| Posted: Mon May 14, 2012 3:47 am Post subject: |
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| CasetheCorvetteman wrote: | | You couldnt hear it cause the fans were too loud |
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km987654
Joined: 25 Jul 2007
Posts: 2874
Location: Australia
TV/Projector: Barco BG809s
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| Posted: Mon May 14, 2012 11:16 pm Post subject: |
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Ok so I have moved on a little and swapped the H-Shift and Focus board but this had no effect on blue it still does not change when adjusting focus so I then changed the focus coil with the same result so in the absence of any other part it looks like the issue is in the blue tube. If the tube is the issue then changing the resolution of the image might have an effect and here is the result of that at 1080i blue will not adjust for focus but at 720p 900p and 1080p blue focus is adjustable. So I will find one of these that I am happy with and settle there so 1080i is off the selection list.
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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Tue May 15, 2012 9:29 am Post subject: |
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I dont see why that would be the case... If it adjusts at one res, it should adjust at others...
Last edited by CasetheCorvetteman on Tue May 15, 2012 9:34 am; edited 1 time in total
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km987654
Joined: 25 Jul 2007
Posts: 2874
Location: Australia
TV/Projector: Barco BG809s
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| Posted: Tue May 15, 2012 9:33 am Post subject: |
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| CasetheCorvetteman wrote: | | I dont see what that would be the case... |
Well case whats the case
What do you see??
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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Tue May 15, 2012 9:35 am Post subject: |
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Sorry mate i had to edit that, i had used an incorrect word in there. Although i also added some more too 
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