CTC-16 combo

[DaveWM]

I have put about 4 coats of tung oil on it, 0000 steel wool between coats, looks great. I also used the 0000 on the metal pull knobs and tuner handles, cleand up the gunk that was left, very nice and shiney. The TT seems to be working better the more I use it, for a while there it was having a tough time on the cycling but lately it works fine. I stole a needle from another RCA that I had a new diamond needle. Sounds excellant. Every now and then there is a miss fire and the record drops the arm lifts and just settles down and then turns off. I can see the little sizing lever is not working right when that happens. My guess is it just needs more use to continue to loosen up.

I tried the brake fluid on the spare idler several days, no change. going to just retread it.

[DaveWM]

touched up the purity, had a tough spot to work out, did another degauss, think I got it. used a dot/bar/crosshatch gen to touch up the convergence, just a tiny bit on the dynamic was needed. Roundies seem so much easier to get it right for me anyway. The CRT seems to be getting better if that is possible, I reset the bias to the top spot on the switch, still have plenty of brightness, tracks well etc....

I will get some more pics in a bit. the only thing I have to becareful of is the purity rings are very loose. I may try some toothpics to hold them in position.

I just know its going to look great when I get the cat off.

[DaveWM]

here are some after convergence. there is still a slight purity issue along the top.

I am going to give it a rest and try again later. I could not get the red cloud very small in the center, maybe just could not move the yoke back far enough.

since it was so large it made it difficult to see how well I was centering it.

[andy]

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[DaveWM]

you are right andy, I just like to make sure its working. I still has the orig diode pack, and I think there maybe one of those cap tube caps. I just cant remember now. If there is a white cap it will get replaced, but I will leave the Se diode pack in as long as its working.

It will prob be a while before I pull the CRT for cat removal. Waiting for warmer weather. Around here the summers get so Hot I am betting that a few hours in the sun will allow it to pop right off.

[DaveWM]

NOS 6C9 in the tuner seems to have resolved my FM distance issue. There is one station that I like that was just not quite making it (the MPX would drop out depending on where you stood). The new tube does not have that issue.

I did not bother to test just did a sub.

[miniman82]

Probably cathode contamination. The contaminates settle on the cathodes after sitting a while, and take some time to burn off when you turn it back on.

[zenithfan1]

The CRT might still be a bit de-activated from sitting. With use, they sometimes "wake up" a bit. Or, the CRT may be getting a little soft and needs time to warm up. I have one like that but the picture is great after about 5 minutes. The tube also tests good, but not as good as some of my other ones. Did you try the 8v heater method to wake it up?

Hey Nick, didn't mean to repeat what you said, we were posting at the same time

[DaveWM]

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.

[marty59]

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.

[DaveWM]

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.

[andy]

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[zenithfan1]

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!!

[DaveWM]

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.

[andy]

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