Restoration begins on Ed Reitan's CTC-7
 

For those interested, you can follow the restoration at this link. We expect it will take several months. Link:https://visions4netjournal.com/2017/...tv-page-three/

https://visions4netjournal.files.wor...5/img_0298.jpg

Such a beauty, I'll be watching it's progress, looking forward to someday seeing that great RCA Color!

That should be an interesting read. I've always wondered what the control system is like on a Worthington.

The commercial for the Worthington is on youtube. You should play it on yours once the resto is done as a demonstration video....It would be fitting and cool. :thmbsp:

Thanks BigDavesTV.

Electronic M: I saw that video and yes it would be cool. We plan to play Ed Reitan's restored "An Evening With Fred Astaire" on this set as a tribute and do a video about him.

Congratulations to this outstanding set!

I know the YouTube Advertising video for a long time and was curious if one of these sets survived. It's great to see this set in good hands to be restored :thmbsp:

Josef

I'm sorry to hear about the wrong CRT in the set. The 7s and early 9s came with the 21CYP22. The late 9s and all of the 10s came with the 21CYP22A. The "A" version has a strange looking red phosphor.

Josef: Nice to here from our friends in Austria. Thank you.

benman94: I'm okay with it. The tube tests good.

Interesting observation about the red phosphor difference between the 21CYP22, and the "A" version of the same CRT. I have an blond Anderson CTC-7B with a very poorly rebuilt (by RCA) "A" tube. The red phosphors tend to look rather dull, and lean toward orange, but not as bad as the 23EGP22 junk from Motorola :thumbsdn:. The green is amazingly bright, and football games look pretty good. The blue appears normal, whatever that is for this particular tube. It's loaded with dead phosphor dots, and doesn't focus well.
I am reminded of discussions about the differences among the 21AXP22, and 21AXP22A about the difference in screen phosphors. Of course we know why the tube was re-designed for HV flash protection, but the phosphor composition of the screens also were changed, IMO. Great thread ! So happy that the set is in good hands! :thmbsp:

The A version also doesn't need the edge purity magnets. Mine are all turned to the defeated position. My 21CYP22A's were rebuilt nicely or are new tubes altogether.

FWIW I haven't noticed any difference whatsoever between the A and non-A 21AXP22 phosphors, it's just that the earliest versions had a greenish hue to them like the 15GP22 had. The rest of them have that paper white look, and I can't tell the difference with my calibrated eye.

I've done tests with a colorimeter on the following tubes:

• 15GP22
• 21AXP22 (green screen)
• 21AXP22A (paper white screen)
• 21CYP22 (grey-blue screen)
• 21CYP22A (grey-blue screen)
• and finally an early 21FBP22 (puke green screen)

The blue shifts slightly toward violet and away from a more cyan color over the years, the red also shifts toward orange, but the greatest shift is in the green. The P1 "Kelly greens" are gone by the time you get to the 21AXP22A; the green phosphor is already substantially more yellow, and the trend gets worse with time.

The persistence of the phosphors seemed to vary somewhat as well, with some tubes, like the 21CYP22A having a bit more lag (something I've noticed, and apparently Pete Deksnis has as well according to his website).

The strange red phosphor I'm referring to in the 21CYP22A blows out to orange with high beam current more readily than the non-A version, at least in my experience. But, the 21CYP22A is much, much brighter than the non-A version. You pays your money and you takes your choice.

I'm unusually picky about how my color sets are set up however; I always drag out a colorimeter to set the white point, check grey-scale tracking, and I ONLY watch my sets in a blackened room. If you're eyeballing the grey-scale and watching in a room with any light, you more than likely will never notice the smaller differences between the CRTs, only the larger ones (say the difference between a 15G and a 21FB).

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.

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.

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

Just curious, but were any of the CRTs prefixed with RE? There was a time in the TV repair world where "RE" tubes were shunned out of ignorance, with technicians believing the tubes to be "rebuilt" tubes vice those with the newer/replaced Rare Earths, with increased brightness and deeper reds. They made the scene i the 1960s, with RCA and Sylvania touting the improve characteristics of the tubes.

http://www.americanradiohistory.com/...-Page-0026.pdf

The funniest part is that rare earths were already in use, it's just the shift to different rare earths (and marketing) that brought about the prefix.

Sylvania advertised the tubes and mentioned the prefix, but still many techs stuck to the ignorant idea that they were rebuilds. Somewhere there is a Jack Darr or Art Margolis article about the fallacy/idiocy...

When I started back in the 1970s, all I ever saw was rebuilt tubes from Channel Master and Empire Video, so the tube labels with any identifying info were long gone..

Does the serial number RH 17516 appearing on the 21CYP22A have any significance?

https://visions4netjournal.files.wor...2/img_0364.jpg

Edit: typo fixed

[quote=etype2;3185797]does the serial number rh 17516 appearing on the 21axp22a have any significance?


21cyp22a

.

[QUOTE=WISCOJIM;3185799]Opps. Fixed. :-)

No. The 15G through 21CYP22A were never manufactured in a later rare-earth type. The 21FBP22 was interchangeable with all of the later 21 inch tubes, so it was possible to stick a rare earth tube in a CTC-11, but I purposely tracked down the oldest FB I could find thus ensuring it could only be a sulfide tube.

The rare earth tubes did bring the red nearly back to '53 red, but the obssesion with deeper reds seems unwarranted to me. The major shift was in the green, and that was never reversed or corrected. Orange, yellow, skin tones, etc all depend on both red and green phosphors lighting up. A yellowish green phophor can make for a nasty orange or yellow even with a good "deep" red phosphor.

All of these shifts and butchering of NTSC's gorgeous color gamut all in the search for slightly brighter pictures. For shame...

Keep in mind these sets were never designed to run at high brightness. All the older crt's before rare earth would lose red upon extreme brightness. Also crt's during that period were all part of the development process and in my mind they all culminated with the CTC 16. After that point you move into the 25apx22 and others and then came all the I don't care sets.

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.

Your forgetting the CTC-20 roundy....That was the last RCA roundy.

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 :scratch2:

It's my understanding that the phosphors are the same in the two tubes you mentioned.

There are three variants of the 21AXP22:

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.

And that's precisely why I watch my roundies in a blackened room. Not subdued lighting, black-out curtain dark...

This is the red on our 21AXP22 with low saturated greens.

https://visions4netjournal.files.wor.../img_43921.jpg

This is the red after adjusting for higher saturation of green.

https://visions4netjournal.files.wor...2/img_9992.jpg

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.

There was a new old stock CTC-7 flyback on eBay not too long ago. Went for about $200 as I recall. Hopefully you find one..

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.

Probably natural, but from the years and heat. Mike is concerned about the heat in the cage. It has no ventilation holes, unlike the CTC-2B. He is going to add ventilation by drilling holes and adding a fan.

When I asked Mike why RCA would engineer a flyback with no ventilation, I said was this a money grab to get repair tech's to the home, he said, "well the fly backs were readily available but possibly to minamize arcing."

Still want a backup when this one fails.

The ctc 7 was my 1st color set, that set used to pop 5u4's like Christmas tree bulbs.

Nick Williams has mentioned time and time again that these sets need to be run between 115 VAC and 117 VAc to avoid stressing components, and I wholeheartedly agree with him. If you dial back the line voltage, a CTC-7 will run forever and a day without popping a 5U4, or worse, a flyback or some other unobtainable part. I use a 500 VA Sola CVT for the job. I get a rock solid 117 VAC regardless of what Detroit Edison is doing.

It's a 10-15 minute job to properly adjust the horizontal drive control, linearity slug, and HV adjustment control, but few people take the time to actually do it. Recapping is not enough. A happy horizontal section is less likely to nuke a flyback...

I agree as well. Why not take the extra step to try and protect something that is hard to replace? Yes, pro and con. It's an insurance policy.

Our entire A/V system is protected, cleaned and filtered by a Furman DSP Model IT-Reference 7. In part, we credit the longevity of a 6 year old flat panel which is run 18 hours a day, every day since purchase with over 39K hours on it. That plus doing an ISF calibration to tone down the retina burning images of an off the self unit.

There is a service tag from 1966 in the CTC7 cabinet. I've been told the set sat idle for many years in a controlled AC environment. The set when purchased was stuck,on channel 10.

You'd be surprised how much horizontal cathode current changes with just a few volts difference AC input, it can mean the difference between a hot sweaty flyback and an ice cool happy one. Having said that, I also agree that going through the horizontal circuit setup procedure is essential to proper operation. Beware faulty parts though, the 7 I sold Ed in Buffalo always had cathode current slightly higher than I would have liked. He later told me he replaced the LIN coil and it dropped even father, which I can only attribute to either copper winding breakdown (the wire itself increasing in resistance), or the slug losing permeability over time.

I guess the lesson there is don't assume your flyback is toast because it's drawing more current than you'd like, failure of some other part is always an option.

It is my opinion that copper wire corrosion in the HV cage is not uncommon. I had this problem on my Hallicrafter 820 set. I think this is exacerbated inside the HV cage due to corona that can cause ozone, which is highly corrosive. A small knick in the varnish covering the wire can expose bare copper which will oxidize over time and physically weaken the wire.

Thanks. The insulation broke away with very little effort exposing this broken wire coming out of the windings.https://visions4netjournal.com/wp-co...8/DSC_5996.jpg

After repair.https://visions4netjournal.com/wp-co...8/DSC_5998.jpg

Nice, but I would j hook the copper wire to make the connection long term stable. In your case it could be better not to touch the connection any more to avoid further damage. I usually clean flybacks (from our european b&w sets) with WD40 to protect them from moisture and soften dried out isolations. Take care if there are carbon track pots and don't use WD40 in this case.

The thing looks so fragile. We don't know if the wire broke just then, when the insulation fell away or if it was pre-existing. The set was working well prior to the discovery. Hate to think about the condition of the rest of it.