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#1
07-18-2017, 01:07 PM
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Based on the tests and observations of benman4 and others, would it be possible that the same phosphor compounds that were used in the 15G also have been used in the non-A 21AX? I have often felt that it might be so, based on the color reproduction of my non-A 21AX, as installed in my CTC-4. See avatar.
Kevin 
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stromberg6 
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#2
07-18-2017, 01:54 PM
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The exceedingly rare "green screen" 21AXP22 with identical phosphors to the 15GP22, 15HP22, and 19VP22. The typical "paper white" 21AXP22 found in most CTC-4s and LB-962 clones. And finally the 21AXP22A, all of which have the same paper white phosphor as the second 21AXP22. The "paper white" screen is still markedly close to the 15GP22 though, as are both variants of the 21CYP22; the shifts went haywire with the introduction of the 21FBP22. The greens are just a little more yellow, and the reds a touch more orange from mid-55 to 1960ish. No true Kelly greens or overtly ruddy complexions.
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#3
07-18-2017, 02:00 PM
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#4
06-22-2017, 11:21 AM
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Appreciate the comments from veterans who know these sets intimately. I'm learning from you. Thanks stromberg6.
We have had our sets calibrated by ISF (Image Science Foundation) since the purchase of a Mitsubishi 40 inch CRT over 20 years ago and appreciate the improvements after calibration. Because of the rarity of the ageing 15GP22 trough 21FBP22 sets, just happy we can finesse a decent image at all. Viewing and evaluating color sets (especially old CRT sets) in darkened rooms is well taken and a must for screen shots in my opinion.
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#5
06-23-2017, 07:51 AM
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Good luck, and it will be fun to see the progress. Several years ago, my friend had a Worthington that I helped him list on eBay. I can't remember what it brought (I think a tad under $1000) However... I was upset with many of the members here at that time, because a few of the "elites" started tearing that set apart and there was a huge controversy weather the legs had been shortened on his or not. (they weren't) and I can see from the pictures of yours, that they didn't have long legs on them at all. It was the typical "Oh.. a rare set is listed, so lets make something up in hopes we can get it for $10.00, but we sure won't want to drive more than 50 miles to get it" Ed's Omaha house was just around the corner from my friends and he even looked at the set and said it was fine. I wonder who ended up buying my friends. I just remember they paid Creighters and Freighters to come pick it up.
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#6
06-23-2017, 08:59 AM
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Maybe its just MOI, but there's just SOMETHING extra special in one of these VERY early roundies.. I'm sure that even the great Gen Sarnoff' s posterior was beginning to get a bit TOASTY, especially since Sarnoff had sold RCA's bankers on this whole "Color" bit, & , up ttil... then, Color had been a big, nasty THUD
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Benevolent Despot
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#7
06-23-2017, 04:21 PM
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Does the serial number RH 17516 appearing on the 21CYP22A have any significance?
 Edit: typo fixed
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Last edited by etype2; 06-23-2017 at 04:57 PM.
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#9
06-23-2017, 04:58 PM
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[QUOTE=WISCOJIM;3185799]
Quote:
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#10
07-18-2017, 12:21 PM
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The main fix for the green shift towards yellow is an increase in R-Y gain, which should be done as a linear matrix in the camera, as PAL and HDTV do. Unfortunately NTSC never standardized the new green and set makers each applied a demod change of their own choosing. While this fixed skin tones, it resulted in overdriving reds due to the nonlinear CRT gun current vs voltage.
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#13
08-15-2017, 02:00 AM
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On the hunt for new flyback for CTC-7
On the hunt for new flyback for RCA CTC-7.
Latest from Mike on the restoration of Ed Reitan's CTC-7 Worthington. https://visions4netjournal.com/2017/...-page-three-a/ "Bad news. When I removed the cage and was able to see where the centering control is, I noticed that someone had been there “before me”. The capacitors that are related to this problem have been changed and the Horizontal centering control is good. I also now, have a good explanation as to why the control was responding as it was. The C1 Winding on the Flyback transformer is OPEN. In the pictures it is the Second winding DOWN as you look at the center of the photo. I was able to tug gently on the insulation of the second wire down and with NO EFFORT AT ALL, the insulation came off and the broken wire was exposed. This wire is only a bit bigger than a human hair. Please find photo. You can see the newly replaced big orange capacitors where someone has been before me. I was able to scrape (with a small razor knife) The oxidation from the wires on one side. I could not get to the other side without fear of the wires completely falling apart so I had to be careful. I tinned the wires with my soldering iron and then carefully lapped them together to re-establish the connection. I had to put on my “Big Boy ” glasses to see this well enough to do the repair. You can see the repaired wire in the third photo LONG story SHORT is this set needs a new flyback transformer. The RCA part number according to the Sams Photofact is 106359 and the 4th photo is a good shot of the flyback transformer for reference. I will fire this set up again tomorrow and see if the control is working properly. This will be done with the cage removed so I can’t leave it on for long that way because of the way it sits on the bench. It gets support from the cage being there and with the cage removed it is very unstable on the bench. . But at least I can determine if the control is working properly and then I can continue with my modifications of the cage for the installation of a fan and increased ventilation. I can guarantee that the life of this flayback transformer is very limited. There is corrosion on the fine small wires where they go in to the transformer. This is no doubt due to heat from hours of use over the years. Regards, Mike Author: Hi Mike, Wow! Talk about delicate surgery! Excellent shots. I know you worked hard to show this detail in photography and even harder to make sure the whole thing did not collapse. Thank you. On the hunt for a new flyback. If it’s okay with you, I think the chassis should stay with you until we find a new flyback. Marshall" If anyone can lead us to finding a replacement would be greatly appreciated. Thanks.
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Last edited by etype2; 08-15-2017 at 02:03 AM.
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#15
08-15-2017, 09:29 AM
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If the repair was successful it may have as much as decades more time left on the fly, assuming temp and current can be kept under control.
Part of me wonders if the copper corrosion is natural. I know this example is a good 30 years older, but I've done ~3-4 Philco 60 chassis cathedral radios (2 more waiting in the wings) and 2-3 of their loss leader cousins the 80 chassis (2 of those waiting my bench also), and all but one of them (a 60 chassis) had either the antenna transformer, osc transformer or both with corroded open windings (and these windings have a coating besides the wire lacquer sealing?/holding them to the forms)...Only one had the problem in the lead-in, the rest were mid winding...Sometimes with multiple opens. The first ones I fixed in a similar fashion to what your tech did, the rest especially the ones with multiple opens I just rewound the ~<20 turns with phono pickup wire. All these sets were ones with good original cabinets, not barn dwellers, yet still were like that.
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Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4
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