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  #16  
Old 07-31-2008, 08:29 PM
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sampson159 sampson159 is offline
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great set and the picture rules! recently a friend passed on and left his wife a nice collection of sets. she will be watching this ebay item!i got a ctc 9 that is in immaculate condition with a super good crt.convergance coils were broken and dave is rewinding them.looks to be a good one when finished.there may be another ctc 100 on ebay soon if this goes for a good price.
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  #17  
Old 07-31-2008, 08:35 PM
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Why do we want these things ? A trouble-prone old TV w/a small screen that is soon gonna be obsolete... Yet I, and apparently a LOT of us, would about happily give up our eyeteeth for one...
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  #18  
Old 07-31-2008, 11:36 PM
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Kirk,

Your usual high quality restoration. Some of the best convergence I've seen on a CT-100. Just a nit-pick, not the original grill cloth. Also, the paper? instruction insert on the inside of the pencil box cover is new to me. Was that a factory item on newly shipped CT-100's?

-Steve D.
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  #19  
Old 08-01-2008, 07:45 AM
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Steve,

The insert is in fact a replica of one that was used on a display set. A high quality copy was given to me as a gift. I can see about obtaining another if you are interested. The grille cloth is from another 1954 RCA Set, but not a CT-100. I could not find one that was good enough. I have been following the 15G progress, looks like it is going to be plan B, a 21AX gun in a 15g glass envelope? Thanks for the kudo on the convergence.

Take care,
Kirk
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  #20  
Old 08-01-2008, 07:48 AM
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Kevin,

Great to hear from you. I will pick up the cheater this weekend. Yes, 6 months up there was long enough. We can work on getting your test jig on line. THe CTC 4 is much easier to work on that way!

Take care and talk to you soon!

Kirk
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  #21  
Old 08-01-2008, 05:28 PM
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Video replacement coils

Kirk.....According to your EBay description, this CT-100's electronic restoration was done to factory spec. I assume this applies to all video peaking coils and video filter coils. These coils are custom RCA items that were universal wound on phenolic forms with air cores and covered with a white plaster-like coating. RCA engineers must have considered these custom coils necessary in the video chains of the CTC2 chassis to achieve near perfect conformance to the original NTSC specification. Unfortunately these coils have a reputation of opening up due to internal corrosion on most CTC2 chassis.

How many of these coils were replaced during yours and previous restorations of this CT-100? Assuming some coils were replaced, what type of coils were used and where were they procured?...........Tom
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  #22  
Old 08-01-2008, 11:50 PM
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Hi Tom,

At some point (I don't know when) If you ordered the RCA stock number for those white coils you would recieve the improved brown ones. I replaced all the ones that I could still get with NOS replacements from Moyer Electronics in 2003. The peaking coils are the brown replacements, but a few RF chokes I had to use a cross reference to locate the proper replacements. For example, RCA stock # 74214 (180uh) can be replaced with a Miller #6180 or a Merit TV-184. They work fine, I have substituted them in place of good coils and saw no difference in the response. It may be true that the engineers wanted those coils made that way, but RCA never felt it was important enough to continue to make them that way..but then again they took many of these sets back and destroyed them also..giving the customer a 21ct55 or a CTC4.

The IF and Bandpass transformers in this set are originals, except for the 3.58 tank that I replaced with an NOS RCA.

I have a complete list of the replacements and stock cross if you would like.

Take care,
Kirk
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  #23  
Old 08-02-2008, 11:19 AM
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Quote:
Originally Posted by Steve D. View Post
Kirk,

Some of the best convergence I've seen on a CT-100.
-Steve D.
FYI: This set is 'in the system' and appears in the Living CT-100 list http://home.att.net/~pldexnis/input/...mbers_List.htm.

In that baseball game screen shot, Kirk nicely captured the 'look' of NTSC color on a 15GP22 driven by a properly calibrated CTC2 chassis. What you see doesn't duplicate the image on the 15GP22 of course, but the 'flavor' is there.

Using just the published set up procedure, it is possible to achieve virtually perfect vertical convergence on a CT-100 as the photos show, but apparently not too in the horizontal direction. Again, as the photos show. This follows statements in early RCA color TV literature that basically says to not expect perfect convergence, due probably to a design issue rather than simply a 1954 servicer's ability and inexperience.

I have seen this set in operation and the gray scale tracking is superb.

Pete
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  #24  
Old 08-02-2008, 10:08 PM
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Kirk,
I would like to get a copy of your cross reference list for the coils. I think the ones likely most critical are the millihenry value coils in the I and Q low pass filters, where the self resonant frequency needs to be reasonably high for the inductors to perform the filter (and delay) functions.
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  #25  
Old 08-03-2008, 11:29 AM
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Custom RCA Coils

Hi Kirk.........Thanks for your prompt reply regaurding the custom RCA peaking and chroma demod filter coils. I certainly welcome your offer to supply me a complete list of replacement cross refferences for these crutial RCA custom coils.

My experence with my 21CT55's CTC2B chassis proves to me that replacing the custom RCA high self resonance, universal wound air core, big coils with small generic, low self resonsnce, ferrite cored coils is totally unsatisfactory.

Incidently, my late SR# 21CT55 still used the original RCA white custom coils, The RCA engineers knew these were essential in achieving the ultimate performance of the CTC2/B chassis intended for use as control room monitors. They knew they had it right the first time. Thanks again......Tom
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  #26  
Old 08-03-2008, 05:20 PM
Kirk Kirk is offline
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John and Tom,

That is some good info on these coils. I will be doing a 21ct55 next and will keep that in mind. This is the cross reference that RCA provided for SAMS in 1955. Again I was able to get most of these from Moyer, and they worked good in the CT-100. Hopefully they will be good in the 21ct55.

RCA#
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  #27  
Old 08-04-2008, 04:26 PM
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Test

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  #28  
Old 08-04-2008, 08:43 PM
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Hi Steve D,

The instruction insert in the pillbox is original issue RCA. One of Ingrid's two Merrills has one. This set works well, the other set has a CRT which went to air, alas. One of these sets was a control room set at WRCB-TV in Chattanooga, TN. Your page has been a superb resource, thanks!
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  #29  
Old 08-04-2008, 09:33 PM
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Kirk,

Could you post a scan of the insert for us that have never seen it before and our sets are lacking this?

Dave A
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  #30  
Old 08-04-2008, 09:48 PM
Kirk Kirk is offline
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Pencil Box Insert

Hi Dave,

Here it is.
Attached Images
File Type: jpg ct-100 020.jpg (102.6 KB, 74 views)
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