[Prometheusbound]

Hi Gang;


Is it normal for the horizontal width of the image to shrink as the PJ warms up?


I have finally gotten the XG dialed in pretty well. The green tube is defective ,VDC rebuild, and Curt is going to come down in the next week or two and replace it but thats another issue. Anyway, Now that the PJ is properly mounted to the ceiling and I have it fairly well adjusted I see that the image width is over 2" wider when the pj is cold then when it is warmed up. It takes about 45 minutes for this thing to stablize. After it has stabilized it looks and works great. Is this width change something that I should be concerned about or is it just the nature of the beast?


As always, thanks for your insight and help

Charles

 

[KennyG]

I would be a bit worried, that is not normal. Your Horizonal and Vertical amplitude should stay the same from startup to shutdown.

 

[Prometheusbound]

Ahhh schucks I was afraid that was the case. Thanks for the info. I'm sure Curt has seen this post. If it's something of concern I know he'll take care of it. FWIW the horizontal size change is consistent on all three tubes. Whatever it is, it's common to them all and not just one. Oh yeah one other thing. When the projector is cold and the image is large I can't see the edges of the image because the area that is blanked does not change. In other words the outer sides of the image are blanked until the PJ warms up and the image shrinks down into the unblanked area of the raster. You can actually watch the image shrink down. It happens slowly and smoothly.









Thanks

Charles

 

[deronmoped]

I wonder if the H-output transistor is going, or there might be a problem with air circulation throught the PJ.


Deron.

 

[Prometheusbound]

I did notice one other thing. When I was setting this PJ up I noticed a "hump" or an inconsistency in the changing of the horizontal size while using the amplitude button. The image would get to a point of increase or decrease, dependant on which direction I was going, and it would seem to hit a point where the amount of change would not be consistant with the way it would act for the majority of its movement. The amount of change seems to stall at this place and then go back to normal. Its kind of wierd.

 

[TheFerret]

Quote:

Originally posted by KennyG I would be a bit worried, that is not normal. Your Horizonal and Vertical amplitude should stay the same from startup to shutdown.

Really, while minute I would say that from a cold startup to a warmed set of tubes mine expands. Of course I am talking

 

[Prometheusbound]

One of the image quality things I've been working on is uneven focusing left side to right side. I was never able to get the right side of the red tube to focus as well as the left. This was not a mechanical or optical adjustment error. I went in to readjust the CRC magnets. This improved the issue greatly and as an added bonus the screen size no longer changes as the PJ warms up! The problem must have been a bad connection on one of the connectors somewhere. In my rooting around I must have bumped it. If it comes back I'll start by wiggling cards until I see something.

 

[Chuchuf]

Curt is going to change the G Tube while still on the ceiling.......

I find it is easier to drop the PJ to the floor first that try and do it while still celing mounted.


Terry

 

[TheFerret]

Terry, maybe its because he's concern with sweat dripping onto the electronics?

 

[Prometheusbound]

Oh yeah Terry, no doubt. I will drop the PJ for him. Since I installed the electric hoist it is as easy as pushing a button.