Marquee Modification Performance enhancement thread

I had a conversation with one of VDC's top engineers (the guy who designed the "new" neck boards) and he doesn't think that the current limiter is going to be a problem nor will there be a problem with voltage peaks when you consider that I'll be reducing the amplitude of the yoke drive signal by a considerable amount. The total voltage drive is going to be reduced...dramatically...and the current demand will be kept within limits and the new value of R175 will be determined by running the set of three yokes with a variable resistor taking the place of R175 and adjusted to an appropriate raster width. With the width setting maximized, I'll adjust the variable resistor for slight overscan, then back off the width setting to something around 90 and that should give an appropriate setting. At that point the variable resistor will be measured and a fixed value resistor of that value will be installed in its place.

Any ringing issues will be evaluated separately.


I will say, yet again, that I have never considered any previous incarnation of the frankenyoke concept to be fully successful. This is because the Thomson focus yokes are a truly craptastic design and in fact it wasn't even that good with the Thomson tubes they were originally made for, which are a significantly different tube.

However, in some cases people have found that they make a worthwhile improvement.

And, yet again, I remind you that the Thomson focus yokes' raster centering feature is only a bit of crutch engineering that allows some degree of compensation for a truly incompetent physical magnetics design. Put good focus yokes in and that raster centering feature will never be needed. I noted that in my first run experiments. The moment I stuck most ANY other focus yokes in the projector, the natural raster centering has always been good enough that there's been no need for any additional mechanical adjustment.

It would be hard to imagine making a focus yoke that is any CHEAPER and more marginally designed than the Thomson yoke. I'm amazed it works as good as it does. But K-D yokes on the SAME tubes work much better in the other projectors that were designed with them.

There are no magical properties to the focus circuits of any other projector. While they are optimized for varying inductive values, the lucky thing here is that the G90 magnetics, with the exception of ONLY the horizontal deflection coils, are already at values that are very close to stock Marquee magnetics values and are thus highly compatible with the Marquee driving electronics.

So, just addressing that horizontal deflection issue will allow the deflection yokes to be used, which allows the focus yokes to be placed correctly, and I've already established to my complete satisfaction that the G90 yoke works perfectly in a Marquee if it's in the right place on the tube neck behind a G90 deflection yoke.

To restate this yet again, I've ALREADY fully tested a Marquee running both one and two G90 magnetics stacks on the red and blue tubes. I haven't tested it on the green channel yet but only because (a) the current limiter is on the green channel) and (B) I need the connectors to build up the other wiring harness adapters. Those are on order so when they arrive, it's time to build some cables and put this project into the active test phase.

It's absolutely bizarre that anybody is, basically, attacking me for my experiments. That's frankly absurd. Am I threatening anybody by doing this? Is it going to do any harm to your work and your reputation? Are you trying to warn me off experimenting with my own projector just because I may be right, thus proving you wrong? Are you that sensitive, that you can't stand to be wroing about anything?

I've been wrong lots of times about lots of things. And it doesn't bother me. I have a thick skin and find that every failure is a valuable learning experience. I fully intend to be wrong again and will never be embarrassed about it, because it validates my experiments even more when I get the RIGHT answer.

Kurt, you've been chased off multiple forums. And to be honest about it, I've been chased off one myself, but for political differences that I won't back off on, or discuss here, either. Maybe you should really stop and think about what it is that causes that to happen. TRY PLAYING NICE WITH OTHER PEOPLE FOR ONCE. And believe me, it's quite OK to be wrong. It's quite OK to have a difference of opinion. It's quite OK to allow other people to have their opinion and no, it's not OK to tell other people they should not pursue what interests them.

Nobody that can tell how they deal with the raster centering running frankenyokes in a Marquee.? Dont you care about the raster ringing.?

Well thats a option, but then you trow away huge portions of the image, im talking about maintaining the full image pushing the raster out of the image. I can do that at 1080P 72hz 195Mhz at a 2400H total, by carefull flare and yoke setup, but if i use the static convergence as woud be needet with frankenyokes i get heavy convergence drift, and shaking image.

Only way to tell is putting up a testpattern and make sure your running 1080P out as it sure is possible to scale and shift the image around in a HTPC or processor, so ull need a good pattern like the SMPTE pattern and see if you keep the 1:1 pixel mapping and how much ur clipping off the sides.

Here is Justins last Calibration with standard Yokes and LCP tubes 14.7fl. 1080P 72hz 195Mhz with raster ringing pushed out with porch settings and yoke adjustment. And a screenshot boosting 17fl on Justins projector, taken with a old Canon power shot camera.