#61
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Here are a couple of pix of the tube at Hawk-Eye. Scotty and I jawed a bit, and he's willing to house it for a while in case the geniuses here (you know who you are) come up with more ideas. Scotty didn't apply Vac-seal to every possible place, plus there may be other things we could do, so thinkin' it over.
The close-up with the Tesla coil shows the "blue glow" (photographs more pink) due to residual air. Scotty says the leak is big enough that he can notice a change over the last 2 days. Eventually, the HV will just make arcs between the electrodes when enough air gets in. |
#62
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Just curious: cured vac-seal is evident at the glass-metal interface in your photos; did Scotty also vac-seal the faceplate?
Pete |
#63
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I thought so too, but Scotty said he only did the faceplate, not the bell.
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#64
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Now a question on what to do in the meantime -
What does it take to replace the metal-cone 21AxP22A with a glass 21FBP22? Can anyone describe a good way of mounting a glass tube, preferably in a way that would allow going back to the original should one appear? I can imagine making a cradle out of straps of some kind, but if the shroud has to be removed, I'm not sure how the yoke should be supported. With the factory setup, the yoke is actually clamped to the shroud, not the neck. |
#65
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21FBP22 Replacement
Sorry for the late reply, I've been working on my own computer system hard drive diaster since the 1st of the month. Lost all my Healey and 21CT55 photos so can feel Wain's disappointment with the CTC5. I replaced the 21AXP22s with 21FBP22s in my CTC4 and CTC2B in early 1960. They are both mounted the same with four struts running from the yoke assembly to the cabinet front structure. The 21FBP22's glass envelopes were wider than the metal coned 21AXP22s so the plastic insulating shroud had to be cut away from its front mask bell and the struts had to be lengthened and remounted to the cabinet's front wooden structure. I used screw-eyes screwed directly into the wooden front. Since I'm not a restorer, this hack was fine with me
I realize the CTC5 uses the plastic shroud to mount the yoke assembly and support the CRT. If it can't be modified maybe the strut and screw eye scheme will work for you. What do 21FB's sell for these days especially the rare-earth A version? Replacing the 21AX's with the 21FBs is the way to go, you won't be sorry..........Tom |
Audiokarma |
#66
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One disadvantage of replacing a 21AXP22 with a 21FBP22 or other all glass color CRT is that you give up the superior colorimetry of the 21AXP22s phosphors.
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John Folsom |
#67
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Interesting adaptation. I also have received pix of an original RCA kit, which is somewhat different, and includes a plastic back plate for the yoke so it can be clamped and supported on-center by the CRT neck.
I don't want to hack up the cone, in case I would get a 21AXP to install later. Also, as John Folsom says, one of my main reasons for restoring the set to operation is to look at the color rendition with the original tube. Any mechanical engineers want to join this project? |
#68
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I'm new to this, so I'm not very familiar with how this board works. It seems there're a lot of very knowledgable folks here. I have an RCA CTC-11. Has run well for many years with easy fixes (replace a tube here and there, etc.) It's starting to need some caps, etc. And I'd like to replace the flyback. Where is a good source for these parts. Also, does anybody have the service manual or any service information for the CTC-11. Thanks. Dave
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#69
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Hi Dave,
Welcome to the forum, It's always nice to see another TV guy join the group. I'm sure someone here has what you need. But, it would have been best for you to have started a new thread about your issue. No biggie though, I made some REAL goofs around here when I first came, still do sometimes.LOL. So, that said, just start a thread about your 11. I would like to see pics. Also, look up Moyers electronics. They might have a fly for you. Try JustRadios for caps, they are reasonable and have a good product. Mark
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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 |
#70
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I don't know how to start a new thread. I'll try it now. I guess I have to give it a title. I'll try "RCA CTC-11."
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Audiokarma |
#71
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Mark:
Thanks very much. I think I was successful starting a new thread. I still don't know how to navigate well. I have pics but I don't know how to post them yet. I'll do it under the new thread when I figure it out. Thanks, Dave |
#72
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Update - I've got dibs on a 21FJP22 (glass tube), but I haven't quite figured out how to mount it. I got info on how the factory mounting kit worked, but it involves a mounting adapter for the yoke that I'm afraid I couldn't duplicate. I also got info on modifying the existing insulating cone to mount the glass tube, but I don't want to hack it up, just in case I might get a working 21AXP22A in the future. So, still scratching my head a bit. I found a 17-inch diameter poly funnel on ebay that might be possible to cut down to make a mounting collar, but it wouldn't hold the yoke.
Meanwhile, I have ordered some replacement small tubes, film caps to replace the paper caps, and new 'lytics. It's moving slow, but moving. |
#73
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I wonder if a newer 21" yoke would be compatible with that chassis? I would think someone would have a spare sitting around, something from a CTC-11-16. I don't know that they changed them up any over those years.
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Bryan |
#74
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i have a nos yolke for the later roundies. steve
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#75
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Audiokarma |
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