Problem with Videoprojektor Zenith Pro 880

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Hi there,

here writes Thomas from Germany

My English is for sure not perfect but i hope you can help me perhaps.

A month ago i bought a used Zenith Pro 880. A cool machine. But this convergence- :M

Everthing works fine-only this blue CRT. See the pic-click on it and it becomes larger-the left edge down is the main problem. How can I adjust this? The Problem is that I cannot adjust an edge seperatly-or is this possible?? If i went the left blue down edge to the right direction, the problem is then at the other site!!

Perhaps somebody can give me a tip? :T Is a seperate adjustment of the Lens necessary?

[George Bellefontaine]

I used to own a Zenith PRO 851, which was an earlier design similar to the 880, but with a different set of features. Your problem is convergence and it probably can't be corrected by the user control. In the 851 you used to have to go under the hood to a panel with several pods that controlled movement of the red, green and blue signals in their respective tubes manually, a process that is tricky and very time consuming. I believe the 880 can be converged by going into the service menu using the remote control. But again, even if you know how to get into the service mode, you can really screw things up if you don't know what you are doing. I would suggest you seek out a tv technician who is familiar with crt projectors. He can converge it properly for you and perhaps check things like focus and color temperature while he is at it.
By the way, the blue tube is the hardest to converge.
Good luck.

[Kevin P]

Zenith projectors are a pain in the A** to converge properly. I believe the 880 is like the 895 and 900, and can be converged using the setup remote. You should have gotten two remotes with the PJ, a setup remote and a user remote. The setup remote is used to set geometry and convergence.

The parameters to set geometry and convergence are pretty coarse. They consist of things such as linearity, pincushioning, keystone, position, etc. Plus for more fine tuning, there's inner linearity, top-left versions of many of the parameters (that affect only the top and left sides of the image--so you'll want to use the main adjustments to do the bottom and right sides, then dial in the top and left sides afterward). Getting it right requires a lot of patience and trial/error. You'll be seeing grid patterns in your sleep for a couple nights afterward. But the end result is worth it, you'll have a very nice image to enjoy.

Just so you know, do geometry first, using the green gun as a reference to get the image square on the screen. Then, once you do that, converge the red and blue to the green. Looking at your picture, it looks like blue is actually more correct, while the red and green are off in the bottom left. But that could be the picture.

[draganm]

I have never worked on a Zenith's before, but it sounds like your problems are entirely user related. Convergence is not that hard unless you don't undertsand what's going on. IF you don't have a users manual, you need to down-load it and read it 2 or 3 times.
Hopefully, curtpalme.com is back up soon as that's got every bit of info you might need. With any CRT, a good place to start is a complete re-set and new set-up from zero. If by chance there is somethign wrong with the set, I think Curt has repaired like 800 of those sets in the last 20 years so he can fix anythign on it. :T

[George Bellefontaine]

Convergence is not that hard unless you don't undertsand what's going on.

That's an understatement, especially if you have to do an analog conversion . It is probably much easier the digital route using the remote, but I wasn't fortunate to have that luxury.And I expect that converging digitally is still a pain. Every movment here, affects something there, etc., etc.

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Thank You

Thank You very much for Your replys!

Yes George, every movement here, affects something there :twisted: .

But I'm cool :W . I found this: If i choose the M-NTSC 'channel', the convergence is much better, near 98 percent to perfect. The picturequality is amazing.

So i have order now a NTSC-PAL Converter to convert my most have PAL-Tapes to a NTSC Signal. I hope it works (why not). :P

[draganm]

That's an understatement, especially if you have to do an analog conversion . It is probably much easier the digital route using the remote, but I wasn't fortunate to have that luxury.And I expect that converging digitally is still a pain. Every movment here, affects something there, etc., etc.

Well normally on a CRT, when adjusting convergenece in a particular zone, it does not affect any other part of the grid. OF course this is a very old analog set with trim pots so it's even before my time and I've enjoying CRT for over 5 years now. I looked up the specs on this thing and boy is it crude. It doesn't even have zone convergence? I guess you just turn the trim pot until the grid is sort-of ligned up and call it good. George I can honestly say that if this had been my previous expereince with CRt I would have run out and bought an LCD too.

Thank You very much for Your replys!
Yes George, every movement here, affects something there :twisted: .
But I'm cool :W . I found this: If i choose the M-NTSC 'channel', the convergence is much better, near 98 percent to perfect. The picturequality is amazing.
So i have order now a NTSC-PAL Converter to convert my most have PAL-Tapes to a NTSC Signal. I hope it works (why not). :P

Well that's one way of dealing with it. What you have basically done is taken the easy way and found a frequency thats closer to the previous set-up and therefore matches the previously saved settings. Normally I would tell people to download the manual and spend a day learning it, that's the only way to get the machines full potential. However, this set is so old and it's capaibiltiy so limited that I just don't see it being worth it to spend so much time on it. According to the specs it's 480i max resolution and won't even do progressive scan 480P . If it was at least an 895 then it would do 1080i beautifully.
http://www.curtpalme.com/PJSpecs_Zenith.shtm

however, if you want to learn the basics this is a good place to start and when your ready move to an 8" electromagnetic focusing set and you will see a hige difference. If you can find a Zenoth pro 1200 then you will see something that will blow your socks off.

http://www.curtpalme.com/Zenith900.shtm
little known fact is that these sets were not actually made by Zenith. Another smaller company was subcontracted to produce these sets, and Zenith simply put their name on it. Zenith also produced these sets for a couple of companies that put their own name on it, namely Runco and Knoll. Knoll to my understanding did nothing but change the name on the sets, but Runco built an internal line doubler for the PRO 900 and 900x and added some aspect memory control into the EPROM and memory chips. The internal line doubler worked well and scaled all video and S-video signals to 480p. The internal line doubler could not be bypassed via the internal menus, however the RGB inputs did bypass it.

Overall the Zenith PRO 88X and 900 series seem not quite as reliable as the older 851’s. The 851’s were tanks that lasted forever, however they are limited to video use and are more or less clunky looking. The 88X and 900 units look a lot sleeker, and even with three internal fans, the sets are very quiet.

The one unique feature of the Zenith PRO line is that they have a shortest throw distance of any other CRT projector. The throw distance for these sets is typically 1.2 X the width of the screen instead of 1.4 to 1.5 X the width of the screen as found on most other CRT projectors. This is due to the lenses that Zenith used in their sets. The lenses lack corner focusing adjustments: Zenith instead used lens spacers. This limited the amount of adjustments that the user/installer had over the corner focusing, but allowed Zenith to use inexpensive lenses as compared to other video projectors, keeping the price down.

On the plus side, the Zenith tubes used in this set are liquid coupled and are dirt cheap to rebuild/replace and are rated at 800 lumens. These tubes are very reliable and last a long time if the projector is properly set up using the maximum phosphor area possible.

The digital convergence also works well, but it tough to get a handle on without reading the instruction manual. Zenith could have done a better job writing simplified software, but oh well…. The user and installation manuals are well written though, and the set has some consumer features such as an internal clock that ‘pro industrial’ sets don’t typically have.

To see how these projectors rank in relation to other projectors for use in a home theater environment see the Projector Rankings page.

For full specifications on these and other projectors, see the Projector Specifications page.

For an overview and history of Zenith see the CRT Primer.

[George Bellefontaine]

George I can honestly say that if this had been my previous expereince with CRt I would have run out and bought an LCD too.

Actually, I didn't run out and buy an lcd. I kept my old Zenith for a few years and , even though it was difficult to converge, I actully enjoyed the experience and considered it a learning one. That old Zenith is now being used by one of my sons. I only switched to lcd, and eventually dlp, because I wanted to go the widsescreen route, plus the old Zenith chewed up too much floor space and the drop ceiling didn't allow for ceiling mounting another crt. But I tell you, that PRO 851 was built like a tank and heavy as hell.

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Yes, but as often is all a question of money.

I paid about 300 Dollar for my Zenith. And it was clear it will become difficult to adjust. There are two remotes and one 'adjustment screws' for the red and blue CRT. More i couldn't find so far.

This pic shows my personal best adjustment-LOL


The quality of the screen is not so bad!

[draganm]

Actually, I didn't run out and buy an lcd. I kept my old Zenith for a few years and , even though it was difficult to converge, I actully enjoyed the experience and considered it a learning one. That old Zenith is now being used by one of my sons. I only switched to lcd, and eventually dlp, because I wanted to go the widsescreen route, plus the old Zenith chewed up too much floor space and the drop ceiling didn't allow for ceiling mounting another crt. But I tell you, that PRO 851 was built like a tank and heavy as hell.

that's exactly what curt loves about them, they run forever. He serviced a lot of bars that had Zeniths and then some of them switched to LCD. Unfortunately ,bars are a terrible environment for any projector. After a year the LCD's had died a horrible death and when the service centers smelled smoke inside the the warranty's were null and void. A lot of of those places wound up going back to CRt's although in most cases they went to newer and brighter sets. I bet your old Zenith will still be running George when your grandkids are ready for their HT.

Yes, but as often is all a question of money. I paid about 300 Dollar for my Zenith. And it was clear it will become difficult to adjust. There are two remotes and one 'adjustment screws' for the red and blue CRT. More i couldn't find so far. !

that's not bad, I know if you had imported a better set from the US you would have paid more than that in just VAT and Customs Duty. ;lx Last guy I talked to in Italy paid $450. :M

This pic shows my personal best adjustment-LOL
The quality of the screen is not so bad!

not bad at all. I have seen $8K Sony Ruby LCOS projectors with much worse convergence than that.

[Kevin P]

Yes, but as often is all a question of money.

I paid about 300 Dollar for my Zenith. And it was clear it will become difficult to adjust. There are two remotes and one 'adjustment screws' for the red and blue CRT. More i couldn't find so far.

Looks like you're on the right track. Just work on that bottom right side some more. Get that side dialed in (disregard top/left), and once you have it looking good, use the T/L settings to dial in the top/left. You'll get it looking great, though it's nearly impossible to get every cross 100% perfect. But you can get it 95% there and it'll look great when watching movies/tv on it.

[Spanky Ham]

Exit,
I would concur with Draganm about going over to Curt's site. I haven't seen or played with a Zenith, so that will be your best bet. Doing converge and alignment can be difficult, but I have simplified it with the use of laser levels. With two of these, I can have a pj set up in just a couple of hours.

I know you are in Germany, but I wouldn't have paid that much for the Zenith. In this day, I would not buy anything less than a NEC PG. I didn't have to look to hard to find my PGs.