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Old 12-01-2014, 11:29 AM
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timmy timmy is offline
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21fb and interior dag

well this 63 silvertone with the original crt has got me puzzled with the post i posted several months ago under gassy crt, with the blue marks extending from the anode button down the bell and stops at the exterior dag but the blue mark is on the inside of the glass. so with the hv issues with this set i am thinking possibly the dag is degraded or compromised in some way shorting the hv in some way with the guns and yet the tube shows very good . there is no purple or blue glow from anywhere with lights out. this blue mark was said by someone here on karma that its a manufacturing defect due to the anealing process in the glass but i dissagree with that assumption because since having this set that mark was not there and should have been there from the day it was built not showing up some 50 years later and just running the set in little bits over the few years i have it formed this blue mark and with that mark forming gave me other problems along the way, with setup problems , color, focus, ect the set just got worse until now i had decided to get into it deep to try to find out whats going on with it but have not had any luck finding anything wrong with the hv regulation. so the question is could this tube test good but have an issue with the interior dag shorting or causing hv loading down somewhere or somehow via the crt gun because of a dag problem. hopefully there is a member that would know the answer to this question about a crt or a former rebuilder of crts. voltages taken from key areas showed good, g1, g2, screen, cathode, cathode currant, hv reg currant, all checks out so if i had a concrete reason to condem the crt then i may take one from another one of my sets but it still gives a decent pic but the color drives are counterclockwise as well as the crt bias i cannot raise them at all as it will bloom as it does already alitte bit on white screen scenes......
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Old 12-01-2014, 01:00 PM
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Eric H Eric H is offline
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In short yes, the guns could check fine even if the internal Dag was defective. Rare fault but it happens, not sure why that would drag the high voltage down though.

This blue mark inside the glass, does it only show up when high voltage is present or is it there all the time?

Did you try another 3A3 rectifier? a weak one is a common cause of blooming.
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Old 12-01-2014, 01:06 PM
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timmy timmy is offline
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tried several 3a3s and a solid state nothing changed. the blue mark is there now permanant which happened slowly over time was not there when i first got the set as i had took the crt out to clean the front glass and removing the bracket and reinstalling it and cleaning the whole crt of dust i would have seen it, it was not there.
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