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post #91 of 101 Old 10-10-2013, 06:56 AM
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How so? Lower?

On another note, I just got a new set of VDC NOS LCP09's and one of the red tubes I installed needs a very high G2 of 72 and for some odd reason I had to lower brightness to 4 !!!

What might be the issue?

Athanasios
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post #92 of 101 Old 10-10-2013, 08:06 AM
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Hi Athanasios,

It's been a while. Having the G-2 set that high might mean the brightness has to be set that low. Why does the G-2 have to be so high? Unless there is something wrong it shouldn't be like that. What happens when you set the brightness to 50 and you lower the G-2?

Scott
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post #93 of 101 Old 10-10-2013, 09:24 AM
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If the G2 is lower then i get a greenish tint even if i set the drive higher. I think the tube might be bad,

Mac told me the potential between the cathode and G1 might be out of balance. He told me to try to run a full white field
at 100 contrast and 100 bright with the other tubes off for an hour or two to see if it helps.


At 50 I have elevated blacks . on my other long bow I have bright at 30. I have always had to go to low bright levels for these long bows.
Maybe its the way they handle G2 in the software?

nashou
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post #94 of 101 Old 10-10-2013, 10:22 AM
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See if the tube will cut-off. Set Brightness and Contrast to 50 and with no input or a black field input see if the tube will cut-off by lowering the G-2. If it still glows with G-2 set very low then the tube might have secondary emissions. A CRT rejuvenator can usually fix that.

Scott
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post #95 of 101 Old 10-10-2013, 04:15 PM
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Quote:
Originally Posted by tse View Post

See if the tube will cut-off. Set Brightness and Contrast to 50 and with no input or a black field input see if the tube will cut-off by lowering the G-2.
If it still glows with G-2 set very low then the tube might have secondary emissions. A CRT rejuvenator can usually fix that.

Scott

Ok set C and B to 50 and the red did cut off at 68 but, when using Tim Martins method for setting greyscale or when using my Calibration equipment I have to
jack G2 up higher than my other red tube. So using the grey scale by eye method red ended up at 76 G2 and 28 Drive. To me that seems high
but it looks ok.


Would running the G2 for red that high damage the HVPS at all?

Oh and let me disclose, I am using this in my Blend. I did swap out the red for blue location on this marquee but also swapped the G2 wire in the HVPS connector on the back of the power supply
chamber. So right from the HVPS i switched the red and Blue G2 wires. they go to the correct tube, I did have an issue at first where I had no G2 because the blade of the connector was bent as to not make contact with the
HVPS blade connector. So let me ask, would a weak contact make for me having to raise G2 on a tube? It might be that....

Athanasios
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post #96 of 101 Old 10-11-2013, 05:39 PM
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Quote:
Originally Posted by nashou66 View Post

Ok set C and B to 50 and the red did cut off at 68 but, when using Tim Martins method for setting greyscale or when using my Calibration equipment I have to
jack G2 up higher than my other red tube. So using the grey scale by eye method red ended up at 76 G2 and 28 Drive. To me that seems high
but it looks ok.


Would running the G2 for red that high damage the HVPS at all?

Oh and let me disclose, I am using this in my Blend. I did swap out the red for blue location on this marquee but also swapped the G2 wire in the HVPS connector on the back of the power supply
chamber. So right from the HVPS i switched the red and Blue G2 wires. they go to the correct tube, I did have an issue at first where I had no G2 because the blade of the connector was bent as to not make contact with the
HVPS blade connector. So let me ask, would a weak contact make for me having to raise G2 on a tube? It might be that....

Athanasios

Running the G-2 higher is actually easier on the circuit than when running lower. It is a shunt regulator so the lower the output the more current and power dissipation there is in the circuit.

A bad connection will usually connect then partially connect so the result will often be a flicker or nothing at all. It won't continuously drop the same amount of voltage.

The adjustments were designed to accommodate all the tolerances of the tubes. They can vary quite a bit so there needs to be a wide range. Don't worry too much if some tubes need a higher or lower setting. The projector was designed for that.

Scott
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post #97 of 101 Old 10-11-2013, 06:29 PM
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Thanks Scott, so running a higher G2 is easier on the G2 circuit in the HVPS and would that also ,ean I'd need a lower Contrast then? And would a slightly higher G2 increase blooming or is that totally a contrast issue?


Athnaasios
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post #98 of 101 Old 10-11-2013, 10:26 PM
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Just re did the set up by eye for the blend. I must say it looks better than when I use calibration equipment!!! So the new settings are much better Used 50 and 50 to start my set up but am viewing
video at 33 and 64.

Now I will use my Calibration equipment to see where i ended up by eye and calibrate one display and see how it looks. Then I'll do the other.


Thanks Scott for the info.
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post #99 of 101 Old 10-13-2013, 09:23 AM
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Quote:
Originally Posted by nashou66 View Post

Thanks Scott, so running a higher G2 is easier on the G2 circuit in the HVPS and would that also ,ean I'd need a lower Contrast then? And would a slightly higher G2 increase blooming or is that totally a contrast issue?


Athnaasios

Higher G-2 is easier on the HVPS. G-2 and brightness are offset adjustments. That means that all the video is shifted up or down. Black, gray, and white are all effected together by the same amount. Contrast is a gain adjustment. The black is not effected at all, it doesn't change. Gray is effected somewhat but less than white. White is effected the most. Blooming is entirely a contrast thing. This is how the projector is supposed to work. I recommend setting the projector up with the video going directly to the projector. Don't do any video processing until the set-up is right then do the processing.

Scott
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post #100 of 101 Old 10-13-2013, 07:40 PM
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Quote:
Originally Posted by tse View Post

Higher G-2 is easier on the HVPS. G-2 and brightness are offset adjustments. That means that all the video is shifted up or down. Black, gray, and white are all effected together by the same amount. Contrast is a gain adjustment. The black is not effected at all, it doesn't change. Gray is effected somewhat but less than white. White is effected the most. Blooming is entirely a contrast thing. This is how the projector is supposed to work. I recommend setting the projector up with the video going directly to the projector. Don't do any video processing until the set-up is right then do the processing.

Scott

Thanks again Scott. That is the one weird thing tho with these Marquee's raising contrast affects blacks more than I like, for every two numeric values of contrast I have to lower Brightness one .

Also with these long bows the Calibration is a bitch!1 I do have a radiance in the chain but have it set to default and use its reference patterns for greyscale not using any of its
processing Red drive and blue drive really alter the low end quite a bit. A few clicks of red drive on 80 IRE makes a noticeable change in 30 ire . I wonder if
it the peking circuit of the vims or maybe the LongBow Software works the Color balance controls differently. I did remove the stock 8 inch tubes with new 9 inch tubes.

But I have calibrated other Marquee's and have not had the same behavior . I remember when I first got these instead of a blue Bump in the middle I had a blue dip .

I know I have gotten a nice flat calibration on my old 8000 with no processor, just a slight bump in blue on the mids.

But i will try a calibration of 20 and 80 using only my Oppo. I will have to set up a new memory for it. then hook up the radiance and the blend scaler to see how much they alter the oppo only calibration.


Athanasios
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post #101 of 101 Old 11-16-2013, 08:56 AM
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I not only do better filtering, but I also decouple all of the data and control lines form the processor and other sections of the PJ. That greatly lowers noise in the low range and brings the low end out better.

pNEg

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