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#76
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when I 1st tested it I did up the filament, not that much, just to see if I could get the emissions up, they did, but would not stay (left it there for maybe 1 hr) when returned. I would not even notice it if it was a daily driver, However I have not really spent any time to see how long it can sit idel before the problem popps up. I have a replacement CRT I plan to use that test very well, I just am on the fence with it since it produces a very nice pic other than this delay issue. I would not even replace it but for the bad cat that I want to get rid of. I may just do the cat and reuse it, I have a CTC 7 that could use the replacement CRT. Its not a dual anode but I figure it will work with maybe some tweeks.
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#77
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Are you "on the fence" as to wondering if you should try to rejuvinate it or not? I agree that the CRT does seem to be on the "soft" side of things but if it's coming up on brightness and the tracking is good, nowadays that's acceptable.
Lately, I've noticed the hesitating of not rejuvinating tubes and sometimes even living with a brightner. Sure, we look at rejuvinating as the last resort but I believe rejuvination is better than the added stresses of using a brightner. And granted, if a brightner was there to begin with "depending" on how long that brightner was in use the tube may still be salvagable (or not). Realizing that sometimes a tube can test poor and still produce a good picture, it is always better to see how it does after the set is up and running. Things sure have changed with no Scotty around anymore! I've taken various approaches to this. On my Zenith 5131/chassis 25LC30 the CRT will need cateract removal and I did check the tube and it's marginally ok. What I mean by "marginally" ok is that the guns all showed some emission but not all the same, weak with poor tracking. It's got life in it so I know that it will be a good canadate to leave until the set is operational and evaluate then. It will work just fine for producing a picture, and it may "wake itself" up in the process. Another set that I'm starting on (57' B&W Zenith) had a brightner on it but the tube came up in emission on the tester, indicating some life even before letting it test for a couple hours. I did take my Beltron to this one and now it checks as new. I may have shied away from doing that but this was done as a last rush effort before Scotty shut down so he was my backup. We've heard that a rejuvinated tube won't last long, picture won't be as good etc. but a CRT won't last very long on a brightner either and then theres no chance of resurrection with a rejuvinator at that point! The Predicta in my Avatar is the original tube that I rejuvinated with my Sencore (before I got my Beltron) and it's been doing good. Now that I have my Beltron I use it for rejuvinating/cleaning and I like my Sencore for testing. Dave, I don't want to hijack your thread and I can understand any hesitations where the tube is concerned as to what to do. If your tube continues to maintain the characteristics that it's showing, I'd bet it would respond quite well to a minimum rejuv/clean as your last resort. |
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#78
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oh no, no rejuv for me, my fence decision is to remove the cat of the soft tube and reinstall or just switch over to the strong tube. I would not dare do a rejuv unless it was nearly a lost cause, this is far from that. I may just de cat and use and save the strong tube for the CTC-7. I would like to see the strong tube installed in this set just to see how much faster/brighter it maybe, but if I go that far I could not see going all the way and installing it and saving the soft tube for the 7.
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#79
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...
Last edited by andy; 11-18-2021 at 05:19 PM. |
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#80
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I've found that the "auto restore" function of the Sencore CR-70 is really good at waking up and tracking them without harm (when the 8v heater method isn't enough). I tried to hurt a crappy tube with it once and couldn't, not saying it can't be done but you really have to try to make it happen. It says hold the button and let it go through three cycles but I've found that one cycle is often just what you need. I had to do it on my CTC-9's red gun and that was 2 years ago and the tube still holds after sitting for a year and then I subjected it to hundreds of hours of use as of now. It tests really strong but still needs a few minutes to warm up if it sits for more than a week, so I guess maybe it's starting to get soft but man, what a picture!!
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My TV page and YouTube channel Kyocera R-661, Yamaha RX-V2200 National Panasonic SA-5800 Sansui 1000a, 1000, SAX-200, 5050, 9090DB, 881, SR-636, SC-3000, AT-20 Pioneer SX-939, ER-420, SM-B201 Motorola SK77W-2Z tube console McIntosh MC2205, C26 Last edited by zenithfan1; 03-21-2011 at 01:40 PM. |
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#81
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I have the CR-70. but am inclinded not to use it, the tube makes a perfect pic, just needs a couple extra minutes if it sits for more than a day unused. I was just wondering if this was something that others have experienced. My plan now is to get motivated (ha) and pull the CRT out, remove the cat, and reinstall. I think I will just save my strong tube for that CTC-7. curiious is there a lot of difference in the circuitry of the CTC-7 vs a CTC-16? I am just wondering if the eariler sets may have been more complicated and costly than the later sets.
Last edited by DaveWM; 03-21-2011 at 02:04 PM. |
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#82
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If she's making a perfect picture, than I guess waiting a few minutes don't hurt. That case I'd leave it alone but I figured I'd share my experience with my tester. I also think saving the strong one for the 7 is a great idea, it's the set that will always be worth more and be more desirable.
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My TV page and YouTube channel Kyocera R-661, Yamaha RX-V2200 National Panasonic SA-5800 Sansui 1000a, 1000, SAX-200, 5050, 9090DB, 881, SR-636, SC-3000, AT-20 Pioneer SX-939, ER-420, SM-B201 Motorola SK77W-2Z tube console McIntosh MC2205, C26 |
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#83
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one of my problems with the 7 is I am missing the back. Its a metal cabinet, faux wood grain, with Lots of surface rust, so not so sure of its value. I was thinking of stripping it and painting it flat black. The safty glass and mask are in good shape, the chassis has some rust, but IIRC the fly looked ok.
I think those have a metal back, maybe I can fab up something for it. I would be VERY nervous to have an exposed neck... oh and of course only after I get it up and going to make sure its not a lost cause. So... thats also contributing to my fence sitting... Last edited by DaveWM; 03-21-2011 at 03:40 PM. |
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#84
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Not black! Then people will think that it's BPC...
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#85
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...
Last edited by andy; 11-18-2021 at 05:19 PM. |
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#86
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I have a B/W Philco with a 21" CRT that's also very slow to wake up. It tests low on emission, but with a brightener it's watchable (not perfect, but watchable) after a few minutes.
I have been debating whether to try the CR70's restore function on that one. I tried it one other time on a weak 17" tube, which helped somewhat but wasn't a miracle cure. Perhaps that would be wiser than running it on a brightener until it completely croaks . . . . Re painting the cabinet black, I don't think that would be awful. I have a CTC-11 with enameled black cabinet and it looks fine (better than faux wood, which I don't like). When I started work on my CTC-7, I was surprised to see that RCA sold that chassis under 46 different model numbers. Who knows, maybe one of those cabinet options was black ![]() Regards, Phil Nelson |
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#87
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Just cover it with some wallpaper with flowers on it. That way it will be preserved until you get the fake wood vinyl stuff.
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#88
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Dave, a very nice restoration. You have the vision of a museum curator!
And I like your new addition to our lexicon - "De-cat" (post 78 in the thread) Simpler to type than Cataract Removal! ![]() Congrats on this set, anxious to see your next project! (and I don't care what color you paint it either!) ![]() Cheers,
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Brian USN RET 22YRS (Avionics/Cal) CET-Consumer Repair and Avionics ('88) "Capacitor Cosmetologist since '79" When fuses go to work, they quit! |
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#89
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Im going to make a thread on this as so as I finish the video. Soaking in water is very effective at removing the safety glass. It just takes a few months.
At this point I would rather use room temp water rather than risk any kind of heat or force. The round crts are just to scarce. |
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#90
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Lol!! its prob been done
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