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#1
05-20-2013, 10:34 AM
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Red focus
Eh, I just noticed something that I've never seen before and don't know how it's possible.
The red gun on my Samsung is a little out of focus.. Not much, I can still see scanlines but not as refined on an all red screen.. But blue and green are crisp and sharp.. I can focus red to be very sharp via the flyback, but then blue and green loose focus just like red.. Would this be a deformed shadowmask? 
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#2
05-20-2013, 11:36 AM
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Could be the red gun has aged differently than the others and needs a different focus from green and blue.
__________________
Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4
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#4
05-21-2013, 09:25 AM
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Not shadow mask, that would cause purity probs.
Its CRT. May check good E but they do lie. If you test it then kill the filaments you will usually see the bad gun (red) drop off faster. Since you have shot the tube already the only alternatives are risky. A brightener OR jump out the low value filament resistor. Risk is H-K short or a shorter life. Gotta run & unhook, T-storm comming........... 73 Zeno
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#6
05-25-2013, 07:14 PM
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The weakest gun will be cranked up and drawing current from a larger area of the virtual cathode in order to get the current desired. This results in a larger spot size, and depending on the profile (shape) of the spot, and the brightness of the raster, will focus differently from the guns that are not driven so hard. You may find that focus is closer on a dim raster than a bright one.
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Linear Mode
