Marquee Modification Performance enhancement thread

There's no need to adjust the raster position with the G90 focus yokes because they're properly concentric to begin with.

The reason for the raster centering feature of the Thomson yokes is because the design sucks. Rather than use ring magnets they cheaped out and put eight bar magnets between two iron rings in a cage configuration. If the eight bar magnets are not exactly matched in field strength then you get a non-uniform and distorted magnetic field which not only causes the beam to be off center, the geometric distortion of the magnetic field (imagine a partially crushed donut) can and will affect the ultimate focus sharpness possible. It's an idiot's design.

I've intentionally dropped a stock focus coil and then tried it out, and neither could I get the raster to center nor could I get anything resembling decent focus.

Stock yokes are just garbage to me. I want them gone and replaced with yokes that are designed to work with Panasonic tubes.


Do keep in mind, the objective of using better magnetics is focus retention at higher contrast levels. You seem to be missing that part.

Trying to use magnetics that were designed for the VERY different Thomson tubes that ran at 40KV anode potential has always been a questionable design choice at best.


Anyway, if anyone does want to try this, the first thing they need to know is how to adapt the yoke wiring to the Marquee. I've made my adapter cables, using cables salvaged from a scrapped G90,
and terminated the ends with the Molex pins used in the Marquee's deflection coil plugs.

The pins are Molex part number 0008500106 and available from Digi-Key. Digi-Key's part number is WM2300-ND.

The deflection yoke wire translation is as follows:

G90 pigtail, red outer to Marquee connector, red inner, position 3
G90 pigtail, red inner to Marquee connector, red outer, position 1
G90 pigtail, blue outer to Marquee connector, blue inner, position 9
G90 pigtail, blue inner to Marquee connector, blue outer, position 11

The short length of the cable assembly attached to the G90 deflection yoke necessitates the usage of a second longer cable.
While I used pigtails salvaged from a scrapped G90 deflection board, you could as easily do this by stealing the cable off a stock Marquee deflection yoke.

The rest is of course pretty easy to figure out. Astig and focus windings are not difficult to decipher.

If you choose to build cables to adapt to the G90 magnetics' plugs, the connector series is the SM series by JST.

If you attempt to run three G90 deflection yokes without first modifying R175 and increasing its value, the current sensor on the green channel will trip and you'll get no image.

At 2400 wide can't you use Long retrace without clipping?

Yes, but I thought that was with 2200 pixel width...

Trust me, I have quite a good idea as to how to set up a Marquee. I've only been doing it for about 20 years now.

I've found that the condition of the LVPS is very important to the focus stability with ANY kind of focus yokes. But the stock yokes have always been the worst when driving contrast to high levels. Of course, nothing else has (yet) worked quite right when tried in a Marquee, this is why I have abandoned the project with the exception of the G90 magnetics, which will be my final attempt.

I've never seen any Marquee achieve the focus sharpness at high contrast that a G90 can achieve. I simply haven't.

There's hardly any point to discussing the merits of LCP vs LUG tubes when LCP tubes in new condition are extremely scarce these days and LUG tubes are still in limited production.

That being said, I am hanging on to two pristine sets of LCPs. One is the first set Lexel ever made, and they clocked the electron guns incorrectly. The neck card ends up mounting 24 degrees clockwise from normal. Sure, that'll work fine. The other set has some hours on them but absolutely no visible wear. They were made way back around 1998 at a guess and were made for AmPro. G2 is on pin 6 on those tubes.

For my own purposes I prefer LUGs. Yes, I have found that getting focus and output uniformity is a bit more tricky with them, because they ARE visibly sharper and thus more finicky. But in actual movie watching it just isn't visible to me. So I don't care or worry about it.

You made mention of focus uniformity issues.  Well, the truth is that with just nine focus zones that really isn't enough to achieve perfect focus across every point on the screen.  If there were more zones, say adding eight more between the outer points and the center point, that'd be quite helpful, but of course we don't have a way to achieve that.  Might as well wish for the moon.

As for the Elcan made HD-10L lenses, I know that some of the earlier production ones didn't get all the anti-reflection optical coatings that later ones did. Lacking those coatings I'd expect more light scatter. Later ones are better. I have two sets of late production ones and I've never noted any apparent light scatter issues.

Anyway, if you're not interested in trying different focus yokes out, that's your choice. Do as you wish. It's my thing, as I've never considered the stock yokes to be anything but marginally functional and merely adequate for the simulator customers that bought the majority of the Marquees that were built.

If you tested those two sets of Elcan lenses and didn't find them good enough for your liking, then at this point I'll just say that I'm apparently not quite so picky as you are. I'm really more into enjoying the film rather than nitpicking the last details about the image quality. Test patterns are useful for informational purpose but I am not like those weird audiophiles that only play music that is "well recorded" with imaging and soundstaging that is so clear that you can hear the third chair violinist squeak one out and you can tell it's a taco fart rather than a sushi fart, rather than listen to music that makes you want to hit the repeat button just because you enjoyed the music so much.

I don't watch test patterns. I watch movies. While I want a good image I'm not THAT hung up on the little details. I'm sure my color balance and greyscale are not perfectly calibrated. Don't care! It looks good and I'm not detecting any lack of detail.

I find the Elcan lenses to be as sharp as any I've tried. That's the most important factor, for me. If there's any ghosting or reflections then they just aren't noticeable enough to bother me. Honestly I have yet to notice any. Good enough!

I really don't want to get into any arguments with you or any contests of any kind. Up to this point I have viewed our interactions as positive and I value your contributions to the hobby even if some others have had their issues with you.

You can focus on any aspect of the projector you wish, and I'll do the same. I won't say anything derogatory or make any snide remarks toward you, or your work, and I would appreciate it if you should grant me the same courtesy and respect.


Now, as for retrace/ringing issues, I will cross that bridge when I come to it.  I have the ability to make some adjustments to porch timings via my Lumagen scaler which is all part of the plan.   

There's also this to consider:  www.freepatentsonline.com/4272705.html

Like I said earlier, the G90 yoke experiment will be the last one. I've already abandoned all other yoke swaps as being unworkable for one reason or another.  None deliver the results in a Marquee.   But it stands to reason that if a given set of magnetics can deliver better performance in a given projector using the same tubes as the Marquee, then there should be a way to make those same magnetics improve a Marquee's performance as well.  That this is possible is not in question.   What is in question is how much of an investment is needed to re-engineer the projector's systems to work withi those magnetics.   I believe the G90 magnetics will prove to have the lowest cost in time and materials to make them run optimally in a Marquee.

so if you dont care and prefer to just wach movies, why not just use a G90, everybody can get one of those for 100-300$ to the point where it wont make sene to try find G90 yokes and put them in a Marquee. mavbe just put a set of Elcan lenses on the G90 wich will boost lightoutput around 8% and further reduce ansi contrast, as the addet light is scattered light bounching around boosting the light output.  You then have a set of HD10F to put on a Marquee and you will see the more vibrant colors as you have reduced the scattered light washing out the image. The Elcan lenses you got was replaced with 2006-2007 build HD Delta HD10L lenses, who had same focus and resolution performans.

I only have one G90, and it will do as i will only be used for test purpose, unless we could stick a Marquee videochain in there..

I do have 5 NOS 9518 1 NOS 9543, and a NOS 9500. Then there is all the rest, think there is arond 10 mint units, 8 of them with HD10E lenses 2003-2005. and then maybe 8 part machines with burned out tubes from around 2007.

With all the time i spend mocking around in Marquee projectors the last 5-6 years i came to the conclution that the videochain is the biggest bottleneck, and a huge part of that is the digital videochain, player processor and dac, only the last few years its been possible to get the lumagen processor to operate as desired, and find a player that dont mess up the source material.

So what im trying to say is if you dont have a good player, and maybe run a old DVDO or Lumagen HDQ processor, your so limited that it dont make much sense to focus much energy to mod or improve anything in the projector, and the focus system if way down on the priority list, as with the right videochain and lenses you will resolve 1080P very very well on screen as is, a LCP marquee will rival a G90 on sharpness and lightoutput. but perform all other image quality parameters much better.