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Old 09-18-2003, 03:50 PM
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Cory Cory is offline
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Weak CRTs

So I decided to put my tester on two of those RCA CRTs that had boosters on them. Both tested in the bad region, but I "Activated" (B&K terminology) them with the tester by boosting fil voltage to 8.8v while under test and waiting about 5 minutes. Sure enough, they both retested in the Good region (the one in the Hillsborough did real well).

What I'm wondering, has anybody had any kind of luck with this sort of thing? I know it's probably just a crutch but how long do you figure they'll last before resorting to poor emission?
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Old 09-18-2003, 05:13 PM
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Depends how long the brightner was on the tube, Most of the time they won't last long, Perhaps a few hours or days of use. If you are lucky, They put them on then traded in or stopped using the set.

Last edited by captainmoody; 09-18-2003 at 05:16 PM.
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Old 09-18-2003, 07:24 PM
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Cory,

I used that method on the 21FBP in my Curtis Mathes set. It lit the tube up like brand new with a great picture, but only lasted a few months. Now, it is back to where it was before with poor emissions and a dark picture. I'm having a tube rebuilt for it now, so, hopefully that will solve that problem!
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Old 09-19-2003, 03:12 AM
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sometimes leaving it running like that overnight will clean it up better.
just did it to a 25gp22 in a zenith that looked really bad when i got to it.ran it at 9v about 12 hours.
checks and looks like new now.other than the green halo
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Old 09-19-2003, 06:54 AM
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Yes, I have done this on some CTC-68's and CTC-92's. I wound 3 turns (appx.) of wire around the flyback core to provide the boost voltage. Put this voltage to one side of a DPDT switch, put the original filament supply to the other side of the switch, ran the switch output to the CRT. I mounted the switch through a hole already provided on the TV back. I then flipped the switch to the boost position for several minutes, then filpped it to "normal" filament voltage. I did this for several days. The CRT was much better. After a month or so, it got slightly dim again, so I used the boost position and then put it back to normal and it was rejuvenated again. The CRT was not perfect after using the boost setup but it was alot better. This flyback setup should not be used on tube sets as it will draw too much extra current.
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