What is this? - Page 2 - Videokarma.org TV - Video

miniman82 · #16 08-02-2010, 04:07 PM

Quote:

Originally Posted by jr_tech

Does the box show any sign of damage? it would take a fairly severe bump to dislodge the shadow mask spring clips from the posts on the inside of the front panel.

No, actually the box was perfect! I was half expecting to get a pile of crushed glass in the mail, but Hawkeye packs them very well. It was mailed with the face pointing down resting on a pile of foam, with a cardboard piece at the base of the bulb to keep it from shifting. There's basically no way for the neck to break, and I doubt it sustained any sort of shock in transit.

I'll try the box trick, but I'm not so sure I'll be able to 'nudge' the mask back into position if that is in fact what happened.

miniman82 · #17 08-02-2010, 04:10 PM

Quote:

Originally Posted by freakaftr8

Look up in the top righthand corner of the CRT pics. See the round black area thats about the 1/4 size of a quarter? Theres the issue. It's a misaligned shadow mask.

Nice try, but that's a piece of the rubber CRT bumper peeking through.

I only intended on sticking this CRT into the cabinet long enough to verify it works, then I was gonna put the CYP back in. Guess my plans are foiled...

ctc17 · #18 08-02-2010, 04:15 PM

I have a shadow mask out of one of these ups broke and it look tough and has a low mass. It would take a super hard hit to bend/warp this thing.

Did your fjp have a safety glass on it when it arrived?

freakaftr8 · #19 08-02-2010, 04:16 PM

Quote:

Originally Posted by miniman82

Nice try, but that's a piece of the rubber CRT bumper peeking through.

I only intended on sticking this CRT into the cabinet long enough to verify it works, then I was gonna put the CYP back in. Guess my plans are foiled...

Ok, got it, but how about that right side of the CRT, it looks as if there is a shadow there at the very egde. Can you use the purity rings or H center to get that out and produce no shadow? That could be the shadow mask.

jr_tech · #20 08-02-2010, 04:54 PM

An interesting picture, if you have time to take it, would be to turn off the color bar pattern, and put up a plain white pattern.... "snow" would be fine... then turn off all but one of the guns. I suspect that the tube will still display a 3 color moire' pattern, but without the color bar information and the complexity of three source illumination, it will be easier to analyze.
jr

***Eric H*** · #21 08-02-2010, 05:31 PM

I'd like to see it too with a blank raster.

I don't think the alignment with the guns is nearly as critical as the alignment with the face plate, each hole is supposed to be precisely aligned with each color dot, even a small shift or rotation of the mask could screw it up badly.

Is the mask held in by anything but tension on the glass, maybe some slots it fits into?

ctc17 · #22 08-02-2010, 05:39 PM

There are 3 spring loaded tabs with holes in the end, Im assuming the holes 'lock in' to molded glass nipples to hold it in place.

I will try and take some pictures when I get home.

jr_tech · #23 08-02-2010, 05:58 PM

Quote:

Originally Posted by ctc17

There are 3 spring loaded tabs with holes in the end, Im assuming the holes 'lock in' to molded glass nipples to hold it in place.

I will try and take some pictures when I get home.

Thank you! I have been looking for pictures of the spring assembly...IIRC, the holes in the spring clips may actually locate to metal (kovar?) tapered posts that are fused to the inside surface of the faceplate panel...not sure, however.

jr

eberts · #24 08-02-2010, 08:25 PM

Either your tube is super heavily magnetized, or the shadow mask is damaged.
If you have the demagnetizer unplugged from the chassis, did a manual degauss, your shadow mask fell out during shipping, guess what, not repairable.
I have seen that happen many times when using UPS as shipping no matter how well tube was packaged.

old_tv_nut · #25 08-02-2010, 09:53 PM

If the mask is out of place, it is apparently leaning back, that is the upper part is farther away from the face (hence the smaller blobs of impurity). Unfortunately, due to geometry, if the mask moves back by some distance, the yoke and guns would have to move back about 10 or 20 times that distance to get the beam angles right for purity, and that is impossible. If the mask is totally loose, maybe you could confirm even by listening for movement after removing the tube from the chassis and rotating it face down. Sorry, but so far this all seems to indicate an unrecoverable accident.

ctc17 · #26 08-02-2010, 09:57 PM

This is the mask out of the tube UPS CRUSHED. This will give you an idea of just how hard core the mask is. Maybe the spot welds broke on one of your tabs and the mask moved back a tad.

sweitzel · #27 08-02-2010, 10:32 PM

I was looking at a photo of miniman's tube when he got it back from Scotty. Is it me, or does the gun assy look totally crooked here? or would that matter at all?

http://www.videokarma.org/attachment...0&d=1280454077

miniman82 · #28 08-03-2010, 12:55 AM

sweitzel: I don't think the gun itself is crooked, just the base.

ctc17: OMG, those bastards DESTROYED that tube!

You're right the mask looks quite sturdy, though as you have seen it's possible for UPS to ruin ANYTHING. Don't those people have standards? I mean, how is their business model viable if all they do it break stuff all the time? To answer your question, no it did not have safety glass because all rebuilds have to have the panel off in order to go through the oven. My set has a flat pane of glass anyway, I wouldn't put a bonded tube in there if I could possibly help it.

freakaftr8: I think what you are seeing is just the edge of the last color bar, I don't remember if there's another one. It's definitely not a shadow.

To all who asked: I'll take a pic with a blank raster for you. I'll cycle through each gun too, so you can see what I mean about how the pattern changes.

miniman82 · #29 08-03-2010, 12:57 AM

Quote:

Originally Posted by sweitzel

I was looking at a photo of miniman's tube when he got it back from Scotty. Is it me, or does the gun assy look totally crooked here? or would that matter at all?

http://www.videokarma.org/attachment...0&d=1280454077

It's just the base that's crooked, but the optical illusion does throw me off. BTW, this is not a tube I had rebuilt, it's one Scotty sold me.

***Eric H*** · #30 08-03-2010, 01:45 AM

Looking at that mask the dots are arraigned in triangles like some of the splotches.

If the tabs snap on to glass posts I can see them getting broken, but then you should have stuff rattling around inside the tube.
I also wonder if it isn't sandwiched inside the two halves which would make it impossible to slid forward or back but perhaps not impossible to rotate, seems unlikely that would happen though.

If the guns were rotated exactly 120 degrees off then it should just have the colors mixed up (as happened with the French 15GP22)