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  #1  
Old 03-13-2011, 07:12 PM
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Zenith6S321 Zenith6S321 is offline
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Restore 21CT55 to schematic or as built?

This is my first post, but I have been reading posts for a bit. Great forums! I am starting the restoration of my RCA CTC2B 21CT55 chassis serial number B8802628. I bought it in the early 1970's and am finally going to attempt to restore it. I bought capacitors and resistors based on the Sams parts list. I started comparing the convergence chassis wiring against the Sams schematic and find missing/different components. I expect this is due to running production changes. Is it generally recommended to restore a chassis to as built or to the latest dated schematic? Anyone know if the Sams 21CT55 schematic represents the "first set" or "final set" design? Any guidance would be greatly appreciated.
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Old 03-13-2011, 07:57 PM
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Phil Nelson Phil Nelson is offline
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I go with what I find in a TV, if it looks original. My theory is that it must have worked when it left the factory.

I would be especially cautious about changing components in the RF and IF sections.

Just my $0.02.

Phil Nelson
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Old 03-13-2011, 09:02 PM
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Sam's folders are notorious for containing errors, so go with what's in the set unless you suspect that it's not original.
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Old 03-13-2011, 09:06 PM
Steve K Steve K is offline
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When I restored mine I went by the RCA manuals and schematics. I don't remember any differences. Remember, Sams often has mistakes. I'd be happy to look up something for you in my schematics or send you a copy if you would like.

Steve
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Old 03-13-2011, 09:07 PM
Steve K Steve K is offline
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Andy:

I didn't mean to repeat what you said, you posted as I was typing.

Steve
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Old 03-13-2011, 09:25 PM
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Stay as made. Rca built it, not Sams.
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Old 03-13-2011, 09:36 PM
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Zenith6S321 Zenith6S321 is offline
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That all sounds like very good advice guys.

Phil, thank you very much for your excellent web site covering the CT100 and your restoration. I also had problems with intermittant loss of color synch in this CTC2B chassis, some 20+ years ago. Now that I can afford the proper test equipment I look forward to trying to track it down. Although the set displayed a very nice picture when last turned on 15+ years ago, it required lots of tweaking as it operated. The 21AXP22A and the flyback were replaced by the previous owner (TV repair shop manager).

Andy, Steve and Reeferman, thanks for the warning about Sams accuracy. At the least I will update my Sams schematic as I recap and verify resistances and check the coils for continuity (maybe I will also try to find an inductance meter).

Steve, I have searched the web for a copy of the RCA service manual/schematics to no avail (except for Sams). It would be very helpful if I could get a copy of any information you would be willing to share!
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Old 03-13-2011, 10:34 PM
old_coot88 old_coot88 is offline
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Ditto on Sams being prone to errors.
Bill(oc)
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Old 03-13-2011, 10:43 PM
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bgadow bgadow is offline
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Welcome to VK! What part of the "free" state are you from? Very desirable set you have...you shouldn't have any trouble getting the answers you need on here.
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Bryan
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  #10  
Old 03-14-2011, 12:02 AM
Steve K Steve K is offline
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Zen...

Send me a PM with your name and address and I will send you copies of the service info.

BTW, I pulled out the Sams and the convergence chassis is different from what is in the RCA schematics.

Steve
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Old 03-14-2011, 06:34 PM
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Zenith6S321 Zenith6S321 is offline
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PM sent, thanks Steve!
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Old 03-14-2011, 06:40 PM
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Zenith6S321 Zenith6S321 is offline
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Bryan, I'm located in southern MD a couple hours south of DC and Balt.
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Old 03-14-2011, 08:30 PM
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Quote:
Originally Posted by Zenith6S321 View Post
I started comparing the convergence chassis wiring against the Sams schematic and find missing/different components. I expect this is due to running production changes.
In a later post you say the flyback was replaced - this may have required changes to the convergence chassis if the replacement flyback's windings are different. So, another vote to stick with what is in the set instead of what's in SAMs.
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Old 03-14-2011, 09:15 PM
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Steve McVoy Steve McVoy is offline
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Zenith6S321, is this a set we have in our database? Could you send me a PM with your name and information on where the set came from?

Thanks.
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Old 03-14-2011, 11:31 PM
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Phil Nelson Phil Nelson is offline
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Quote:
Originally Posted by Zenith6S321 View Post
I also had problems with intermittant loss of color synch in this CTC2B chassis, some 20+ years ago. Now that I can afford the proper test equipment I look forward to trying to track it down.
If you find any good tricks, I'm all ears. I do need to revisit that issue. Just got distracted with some other projects while waiting for my brain to grow a couple more hat sizes

Phil Nelson
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