CurtPalme.com Home Theater Forum

[dentree]

147

[cosaw]

At first sight, if I really had no other choice, I'd be inclined to mod the deflection yoke before trying anything with the focus yoke. One thing at a time, it's more work to go incrementally, but is safer that way. My only concern with that is the metal clamp and changing it's position slightly. I guess the black cables on the clamps go to earth? Does somebody know why? They are only touching plastic as far as I can tell. Does earthing them mean they don't interfere with the electron beam or something else? Is the clamp expected to be in that exact position? If it is then we shouldn't move it. I'm guessing though that I'm being over cautious and it's of little concern. Anyway this mod is easier to undo than any mod to the focus yoke.

As it seems Case has already considered, 7.5mm might make all the difference.

[dentree]

It would seem that the only 8" projector that uses the P16LNP tubes in the BARCO line is the CINE 8 ONYX


Well,I found out that the plastic left sticking out from the rear of the deflection yoke after moving the clamp forward happened to be the same thickness as the centering collar on the deflection yoke, so was able to slide the focus yoke right on to the deflection yoke, as a consequence the deflection yoke can still be locked off, the focus coil front is securely centered on the neck and is locked off at the rear, so far so good.
The net result now is that I can actually crack focus on all 3 tubes, and can actually start to soften the focus at ZERO, but the results from an electronic stand point are not impressive.

At critical focus the settings are:

RED = 25

GREEN =10

BLUE = 7

Which I suppose is better than not being able to crack focus at ZERO, so obviously in the scheme of things, given we are dealing with the wrong tubes this is an improvement, it's odd though that the most significant improvement shows up in only one tube, I have also tried sliding the astig magnets back and forth, there is a point on all 3 where it seems to be better.
One thing that puzzles me is that it is quite possible at ZERO to actually crack focus using the astig rings.

I am by the way doing all this at 15.75K @50Hz with no sources connected

Obviously the whole thing has serious anomalies tho.

If all these problems stem wholly from the wrong tubes being fitted (and working on the assumption that all the electronics are in fact OK) then I was wondering if I were to take a tube from the BG 808 which is focusing to within 10 points either side of mid point and transfer the whole chain into the CINE 8 all things being equal it should focus up as is had in the BG 808, if it didn't, then something in the electronic chain in the CINE 8 would then become suspect, however having said that the one unknown factor is whether the neckboard pinouts are the same, or in fact if I were to transfer the BG 808 neckboard along with the tube it would mean transferring the G2 module also into the CINE 8 then the question arises, would the connections to the chassis be the same and be looking for the same voltages??

The information that would be needed I think is the physical pin configuration of both the PL16LNP AND THE 180DVB22 TUBES, so if anyone has that information, it would be very useful, what I would also like to see is a drawing/photo of the actual component layout of the PL16LNP with the attachments in place ( I have a document here which covers the tube replacement for a BG 808, but the CINE has different neckboards, and there must be something else on the neck that is different to the BG 808, because the unknown factor is the physical size and specification of the CINE 8 tube neck arrangement.


Trevor

[dentree]

The picture of the original deflection coil and focus coil relationship is on Page 15...jpg 234

[dentree]

Has anyone got a CINE 8, ONYX or a photograph of the deflection yoke along with the measurement from the front coil windings to the clamp at the rear.
I want to know if there is a difference in yoke design as opposed to the yoke on a BG 808, specifically if it is different, is it of a shallower design?

[dentree]

i have researched this tube issue further through Curt's pages and I find that the only 2 projectors that used the
P16LNP tubes are the Barco Cine 8 and the Zenith 1200 (re-badged from Barco, I can find no other users of these tubes,although on ebay there is a set for sale (P16LNP) made or sold by VDC?

Also the Zenith used HD 215 lenses which have lousy corner focus apparently (mainly due I suppose because they only have 1 focus knob for the center and no adjustment for the corners)

I am concerned that so few of the ONYX were made (don't know about the Zenith1200) that there may be no real hoe of finding out if the deflection yoke for the ONYX or the Zenith are of a different design to the Cine8 and or the 808, if he tube electrics/magnet arrangement are physically the same size then I cannot see where this problem originates

[CasetheCorvetteman]

Ive just had a quick read over this Trevor, and from what i can gather being able to move the focus yokes further forward toward the bell end has improved the situation somewhat?

If that is the case, then id be even more confindent in saying the tubes are indeed a touch too short for the stock yokes as they are, and minor mods to the housings may well indeed offer what you need to make this right.

Id probably remove the locking ring from the focus yoke and slide it up against the deflection yoke if it was me, the deflection yoke will serve to centre the focus yoke at the front, and the clamp at the back end of the focus yoke will still prevent it moving.

I personally cant see any good reason not to do this, but id want to hear opinions from the likes of Keith, Ron, Barclay66, etc before i would give the nod for you to do it on your own machine.

[CasetheCorvetteman]

The ONYX and the Zenith 1200 PRO are indeed the same to a point, the lens and some firmware are slightly different between the two.

Its not so much that the tubes wont work in your machine, but the fact theyre shorter, which is something i referenced muched earlier in this thread in regards to the P16LJE tubes used in both the XG and the PG XTRA, with the '09' variant used in the XTRA being electrically the same as the '08' used in some XGs and the G70, however the '09's are a bit shorter, when used in an XG youre never able to get good electronic focus when using original XG neck hardware, yet use of '06/07/08' tubes in an XTRA with original XTRA neck hardware is no issue, but the tubes are too long to allow full swing of the red and blue. The focus yoke used on the XTRA is shorter than the XG focus yoke, which is fitted hard up to the deflection yoke instead of there being room to move it fore and aft, such as on the PG.

It is on that knowledge that i based that whole theory, as well as knowing that with a Barco, moving the focus yoke toward the bell end will result in a higher number when it comes to electronic focus.

The tubes may indeed be wrong for the set and more so have the wrong neck hardware fitted for optimal numbers in electronic focus, but i dont think it is beyond making them work fine, if indeed the others agree with my opinion to remove the locking ring from the focus yoke and slide it foward onto the conical shaped clamp section of the deflection yoke, moving the screw clamp forward on the def yoke as i noticed you have.

[km987654]

Can I ask if you have removed the lenses and had a look at the focus on the tube face? I am being a bit lazy here without reading back through the whole thread.

[dentree]

Thanks for that Casey, however if you have a look at the pics you will see that in fact I have managed to push the focus yoke hard up to the re-positioned locking clamp on the deflection yoke, there is nothing to be gained from just removing the front locking ring unless I was going to cut off all the thread section back to the face of the focus coil itself, I am going to have a look on ebay to see if there might be some focus yokes for sale (something to practice on) before committing to the real thing as it were, If I were to cut off the font ring thread assembly we would get another 7 mm of forward movement.

Just as an aside I was wondering what the length of the deflection coil is on your CINEMAX, more than anything I am trying to eliminate the idea that different tubes have different deflection coil arrangements, Because the BG 808 measures 115 mm overall, and the CINE yoke is only 110 mm using the same reference, so just between these two models there is a 5 mm difference

[CasetheCorvetteman]

On my CineMAX the focus coils are not only HUGE, but theyre also larger in the bore for the 9" tubes.

Cutting the threaded section away from yours is my suggestion at this point yes.

Keith, the optical focus being out would prevent sharp electronic focus all together, you will hit a certain level of focus and then notice little change due to optical being out, so id say we can rule that out when he states he cracked some sharpness at higher electronic levels than before.

[CasetheCorvetteman]

Gábor may indeed be able to confirm what i have stated about the size of NEC focus yokes on both XG and XTRA sets, as he has both there, im not sure if the def yokes vary in size on those, but reasonably sure the focus yokes have a noticable size difference.

[dentree]

Thanks km987654 for your question, and yes I have done that and the focus condition at this point in time is on a par with the result on the screen so I am assuming that (if and when) critical focus on the faceplate is achieved it will be seen on the faceplate and likewise on the screen, right now the exercise is to manipulate the neck gear to effectively create a more normal (acceptable electronic number reading) at the point of cracking focus

Trevor

[km987654]

[km987654]

[CasetheCorvetteman]

If optical focus is out, optimal electronic focus will still be seen at the same point.

The focal points are still the tube face and the screen, there is really only one perfect adjustment for optical focus.

[CasetheCorvetteman]

[km987654]

[CasetheCorvetteman]

Im not sure what variations youve seen on your Barcos with and without a source as far as electronic focus goes, but in my experience it made no difference on my CineMAX, although it makes a bloody big difference with an NEC.

[km987654]