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  #31  
Old 04-03-2017, 09:40 PM
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Post the part number for that IC when you get a chance.
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  #32  
Old 04-04-2017, 12:06 AM
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Hopefully tomorrow I'll get around to doing that. I was just watching The Late Show with Stephen Colbert, and if you've ever watched that show, there's a lot of different colors and scene changes. All the different colors drove the Sylvania's color demodulator crazy. It was as if a minion was constantly adjusting the tint control, and sometimes, turning the color control to max and then back down again. Here you can get an idea of what is happening. Flesh tone is correct, but the ocean is both green and blue.
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  #33  
Old 04-07-2017, 03:56 PM
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Quote:
Originally Posted by bgadow View Post
Post the part number for that IC when you get a chance.
Sylvania part numbers for ICs and transistors went something like 13-xxxxxx

edit: I have a schematic which shows a sylvania part # 15-37704-1 IC std 14 pin DIP with a block diagram having two "demod" and three color difference amps. Looks rather simple
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Last edited by DavGoodlin; 04-08-2017 at 07:38 AM. Reason: correction
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  #34  
Old 04-07-2017, 11:04 PM
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I'm not sure I follow what's going on with the color, so forgive me for thinking out loud. If this set uses an IC for the color section, and it's basically working but varying, it could be the IC, but it could also be the control voltages, including intermittent connections, or problems with bad filter caps if the controls supply DC voltages rather than video signals. Also, does this set have some sort of automatic color switch that could be intermittent?
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  #35  
Old 04-07-2017, 11:13 PM
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Based on what I've seen and heard, Sylvania was slightly ahead of all the others on their phosphor formulation. ...
You've heard right. Sylvania was always finding a better processing sequence for their phosphors - the precise formula, heat treatment, grain size, slurry thickness, you name it. As I have posted elsewhere here, when I was at Motorola, Sylvania came up with a thick slurry that was brighter, but when Motorola tried to duplicate it, they had trouble due to swirl marks developing in the screens. The thicker slurry apparently needed a different swirl pattern/rate that the Motorola deposition machinery wasn't designed to do.
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  #36  
Old 04-08-2017, 07:46 AM
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As I recall, Sylvania had a CRT plant first in Emporium, PA then later a modern plant in Seneca Falls, NY. Thier color bright 85 replacements outsold RCA at our local parts house. i usually chose RCA for an RCA set, IIRC.

The RCA CRT plant in Lancaster PA (here I am) and Marion Indiana were also developing a better phosphor

All these locations are nowhere near big cities. Those Engineer-Physicist types hated cities and I can understand why.

Unfortunately all the old timers I meet from this RCA plant worked in power tubes and orthicons.
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  #37  
Old 04-08-2017, 11:10 AM
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...

Unfortunately all the old timers I meet from this RCA plant worked in power tubes and orthicons.
Well, not so unfortunate if you are interested in orthicons. I would love to know the details of how the thin glass orthicon targets were created - like a thin glass bubble, but perfectly flat.
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