CurtPalme.com Home Theater Forum

[trebortaergeht]

All three tubes have low emmision. i didn't notice till today when I was going to perform a grayscale adjustment and found that all three G2 levels are above 75, Red is at a whopping 90! I hadn't noticed because it is still so much brighter than the barco 701 I was using before. I had checked the p14 filament voltage when I got it and it was fine and still is fine, it must have drifted back to the proper level when I moved it. it really makes me sad considering there is less than 1500 hours on the tubes and they still look like 9's. It's even worse that even a single tube costs as much or more than I spent on the whole projector. Although its still quite useable (I'm using it right now) , the tubes probably only have a couple hundred hours left.

[Tom.W]

1500 hours on the tubes seems quite low to have effected the emissions that much... Do you have a CRT tester and if so what kind ?

[trebortaergeht]

I don't have a CRT tester, there seems to be quite a few on ebay though, any suggestions?

[Tom.W]

The Sencore CR-7000 is a good one.


http://repairfaq.cis.upenn.edu/sam/reppic/sencrt.pdf


When was the projector made ?

[trebortaergeht]

manufactured December 1995

[trebortaergeht]

An update. I just took a look at the grayscale again and had to drop down the G2 levels. right now its at red 82 green 74 and blue 71. Filament voltage is still at 6.35. I think there may be a problem elsewhere causing the G2 to drift, any suggestions?

[Nashou66]

Do an Initialization of the PJ. That solves many software glitches. you will have to do a complete set up after though as it clears all memories.

Athanasios

[dvh99]

hvps maybe have a spare to test.

[dturco]

What were your contrast and Brite levels? If they were set low like in the 30's it would be the same as if the G-2s were "correct" and brite and contrast around 70 each I think.

It might not be as bad as it seems, but how they got that high is curious.

[Curt Palme]

Do it this way: Set the brightness and contrast to 60. Put up the stepped gray scale and set the G2 so that the 0 IRE rectangle is _just_ lit on the face of the tube. See what the G2s are then.

As long as you have good grayscale and the filament voltage stays at 6.35, you'll be good for a few more years I'd think.

[Curt Palme]

Do it this way: Set the brightness and contrast to 60. Put up the stepped gray scale and set the G2 so that the 0 IRE rectangle is _just_ lit on the face of the tube. See what the G2s are then.

As long as you have good grayscale and the filament voltage stays at 6.35, you'll be good for a few more years I'd think.

[draganm]

[Tim in Phoenix]

Hello


Try this and report back: http://www.etechvideo.com/techtip1.htm

And see if your hvps is on par with a voltmeter:

G2 Values and Voltage, measured at tip of VNB R76:

G2 of 40 gives +375vdc
45 +415vdc
50 +462vdc
55 +510vdc
60 +555vdc
65 +600vdc
70 +646vdc


Also, I have some super-minty nine inch tubes for sale, reds, blues, or full sets, phosphor rating ten, guns 8+


.

[trebortaergeht]

Thanks for the suggestions. I'll try these out after work and post my results

[trebortaergeht]

after doing a full initilization up and letting the projector warm up for over an hour, I took a look at the grayscale again. with the contrast and brightness both at 50 my G2 levels are as follows: red 80 green 77 blue 72. Red is a little lower but green and blue a little higher. I will have to check it every so often to see if there is any drift. I am unable to check the G2 voltages at the moment since I left my meter that can handle the high voltages at work.

EDIT: thirty minutes later my G2 levels now have to be at red 90 green 81 and blue 77. the g2 requirements are drifting all over the place, there must be a problem with the hvps. I'll have to remember to bring my meter home tomorrow to check.

[huggy]

The Great Robert




Dave

[trebortaergeht]

[AnalogRocks]

Ooooo I love anagrams

[AnalogRocks]

Ooooo I love anagrams

[Tom.W]

[SkcorGolana]

[huggy]