CurtPalme.com Home Theater Forum

mp20748 · Posted: Mon Jul 24, 2017 10:01 pm Post subject:

I did have a few run of boards that had limited light output, and that's one of the reasons I offered the upgrade. Mak's boards were different, he o lay complained about a blue neck board problem, that he sent to me and I fixed it. One of the small series inductors fell off the board. A part I didn't change during the mod process.

After getting his boards the green has a marking on it that says focus problem. Not sure why that was there. I didn't notice the problem after maki g the changes to the boards, but did noticed it when pushing the contrast. And as he keeps saying, he only mentions a problem with the blue neck board. No mention of the green. Plus he forgets he sent me his contrast settings, when I was trying to find out if he had the limited problem. The green blooming problem had been corrected when the boards were here.

Concerning blooming, it could also be caused from weak tubes or low high voltage. And on an older marquee, it could be a number of other things as well. But for sure, no mention of a limited contrast or bllomimg problem was mentioned, just as in his many reports of the blue neck board failure. He never mentioned the green problem, nor was I made aware of a limited contrast. And it was not seen here

**Curt Palme** · Posted: Mon Jul 24, 2017 11:12 pm Post subject:

I deleted the last two posts. MAK, you have the tracking number that Mike has given you, he sent it to me as well.

Posting more insults isn't going to do anything. Mike has sent you back your boards, you've accomplished what I allowed you to do by posting publicly.

Enough already.

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I stand by my statement because I've TRIED other focus yokes in a Marquee and while every one of them changed the way the machine focuses in one way or another, most of them caused the machine to exhibit little to no blooming at high contrast levels, even leaving the stock neck cards in place and untouched, aside from of course having to remove and reinstall them as part of the yoke swap.

The fact of the matter is that the Thomson focus yokes that are stock on Marquees were engineered to match the Thomson CRTs that
the earliest Marquees were equipped with, and those Thomson tubes were built for a 40KV anode voltage and that totally changes the beam current profile which alters the magnetic field properties required to focus the beam. That dictates a different focus yoke design.

Even then the Thomson focus yokes did not deliver the sharpness even on Thomson tubes that we have come to expect out of our 8 and 9 inch Barcos and Sonys and even, yes, AmPros, too.

Panasonic's "partner" for magnetics was Kanto-Denshi. Electrohome is the only company that chose Panasonic projection tubes that DIDN'T choose to go with K-D focus magnetics, but when Electrohome switched tube vendors they chose not to re-engineer the Marquee chassis to work with K-D magnetics as it wasn't necessary in order to still meet the specifications set forth for their target market, that being the flight simulation market. If it's good enough, why spend the money to re-engineer it to be better when the customers didn't care?

That still doesn't change the fact that Marquees are the weakest performing projectors when it comes to focus performance, of all projectors that use the same Panasonic family of tubes.