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CRT Rejuvination tips and tricks
I thought it would be a good idea to combine all the tips and tricks on CRT rejuvination. Here's what I've picked up:
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Last edited by bandersen; 06-11-2010 at 04:04 PM. |
#2
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One I'd like to add:
Never Rejuvenate/Clean and Balance/Restore a CRT with it's face down. All the junk that's blasted travels down through the gun(s) and can short the CRT elements. With the neck parallel to the ground, the junk usually falls to the bottom of the neck and harmlessly away from the gun(s). I've had this painfully ($$) demonstrated on a customer's CRT... Also, if you are using a B&K 4XX series checker, don't use while your bare knee is in touch with the ground. Shocked the %*!& outta me when I was a teenager and checking some CRT's for a friend. He had about 30 B/W CRTs spread out on a blanket in his back yard and I went about testing each one - I got to one and got between the checker frame and the bare ground - ouch! Worms came up outta the ground..... Cheers,
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Brian USN RET (Avionics / Cal) CET- Consumer Repair and Avionics ('88) "Capacitor Cosmetologist since '79" When fuses go to work, they quit! |
#3
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When I was in college I use to get trade in tv's from the rca dealer in town. I fixed them and sold them to students for about $40. He would let me have sets he didn't want for $10. each. The XL-100's usually had bad or low emission tubes. I use to get the 17" or so Mural RCA's with the toggle power switch on it, they were good sets tubes aged gracefully. Well the XL-100's that had bad emissions I use to put a variable power supply across the filiment turn up all the guns and brightness to the max make the tube as bright as possible and then crank up the filiment. After about one or two hours I would whack the neck of the tube with a screw driver until I herd a sharp crack and a nice spark jump inside the tube a few times. The tube would brighten up nicely and when I returned all the settings to normal, and rewire the filiment I ended up with a nice working tube. I did dozens of these tubes like that and naturally never really hit them that hard, never had one break. If I had only one gun giving me trouble I would just turn that gun's drive up and still whack the thing good. This was my last ditch effort at the time, since my investment was not large I really didn't have much to lose. If anyone wants me to give it a try on your roundies after Scotty retires just send me a note........ : )
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Yes you can call me "Squirrel boy" |
#4
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back in the shop days,we would "wrap"a crt.cut one filament wire and add a section that we had wrapped around the flyback.1 or 2 wraps usually would increase voltage.let the set play for 30-45 minutes.if the crt brightened during the process,then great!some tubes took longer and some required more wraps.in my over zealous youth,i wrapped some too many times.the picture was good for a day or so,then,suddenly,lights out.i learned to be more cautious in my old age!
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#5
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Don't forget to tap the neck to try to clear any shorts that pop up on the tester...
What a lost art this is. I wonder what the crt engineers thought of testing/rejuvination and all the black magic that goes with it... |
Audiokarma |
#6
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Here's a video I made showing how to reweld an open cathode using a Sencore CR-70 https://youtu.be/E3E8EDMZ8aI?t=20m23s
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#7
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that's a great video Bob!!
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#8
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Worked for me
Thanks for the post, I am working on the same set you posted on You tube, Admiral 14YP3B with a 10ABP4. It tested dead I tried your fix, took 5 tries before it took.
Now I have a bright picture, life test showed good. Thanks again. Carl |
#9
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That's awesome! I'm so glad it worked for you
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#10
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This thread needs sticky status.
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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 |
Audiokarma |
#11
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Quote:
Along with adding a winding to a flyback supplied filament there is also usually a low ohm resistor in series with the filament, jump it out. IMHO also last resort but effective ! Sears / Sanyos with Sylvania CRT's that H-K short. Anyone remember the mod ??? IIRC get the filament above ground, add a 1.5 meg from the filament to the shorting gun. Also add a .001 cap to ? Saved a crap load of sets, also worked on others. 73 Zeno |
#12
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any tricks out there to revive a 7jp4..... maybe put it in front of a crystal ball and do a rain dance, lol...
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#13
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...
Last edited by andy; 11-20-2021 at 03:34 PM. |
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