View Full Version : Restoring a RCA 21CT55


etype2
01-21-2017, 12:57 PM
https://visions4netjournal.files.wordpress.com/2016/12/img_2449.jpg

Well over a year ago, we purchased a 21CT55 from the Early Television Foundation. It has been a long haul, 470 days and the restoration is completed.

Steve McVoy, Dave May, Bob Galanter, Kevin and Mike Doyle (edit: I left out Walter) all members of this forum helped with the restoration. I want to thank them very much. It could not be done without your help.

You can see screenshots along with a chronological accounting of the restoration from day one at this link:

https://visions4netjournal.com/vintage-rca-color-tv-page-two-2/#jp-carousel-967

Moderators, apologies for the large screenshot. Can you reduce the size?

walterbeers
01-21-2017, 02:40 PM
Very good job. Looked at the pictures on the visions link, and the color is great. I have a 21CT55 also that I restored, and is working as well.

etype2
01-21-2017, 02:52 PM
Thanks Walter. I forgot to acknowledge you. You also helped me isolate the power switch problem.

I followed your 21CT55 restoration thread. Was inspired.

jr_tech
01-21-2017, 03:25 PM
Wow! Wonderful restoration and documentation of the restoration of one of the very most desirable of the milestone color sets!

jr

walterbeers
01-22-2017, 04:37 PM
Out of curiosity what was the problem with the power switch. If I remember right we chatted online and you said it was dead completely. I suggested the power switch and some of the places you could check it out without pulling the chassis. Was it the switch itself as I suspected? If so did you find a replacement switch with volume control? Also is your cabinet the original finish? Looks really good in your first photo. Mine was really sun faded, (especially the top and one side), so I finished it with Minwax stain. I really should have had the cabinet professionally refinished, but was afraid to remove the 21AXP22 as I didn't want it to go to air. Sanding and stripping the cabinet (with the CRT in place) also felt very risky because of the vibration if I had left the CRT in the cabinet. Maybe someday I'l be brave enough to remove the CRT and take the cabinet to a pro refinisher.

Tomcomm
01-22-2017, 05:29 PM
Welcome to the 21CT55 club. I would like to see some full screen size, screen capture shots. I assume your included screen shots were thru the full RF/IF systems, right? It would be interesting if you could compare them with your computer monitor screen shots. Seems you have some color aliasing contamination in the small detail. Looking forward to your further screen shots.

etype2
01-22-2017, 05:41 PM
Walter,

You were right, it was the power switch that failed. We found out the switch was a replacement sometime in the set's history. It was incapable of handeliing the high current on power up. The switch had a 3 amp rating but the transformer was drawing higher current. Mike suggested we install a relay to draw the current and lessen the load on the switch which was replaced to the correct value. This was done to preserve the switch for long life. I'm so glad we did because the room light dims briefly on power up. The brightness control and volume control which were integrated with the power switch were retained.

The cabinet was in good shape. There was one scratch on the side which was touched up without refinishing the entire cabinet. The safety glass was removed and the CRT and glass were cleaned. I share your concern and the CRT was never removed during the restoration.

I need to refinish the brass around the safety glass. I don't want to remove the glass if possible. Do you know of a good product I can use to remove the patina? I tried Brasso and it had no effect.

etype2
01-22-2017, 05:54 PM
Welcome to the 21CT55 club. I would like to see some full screen size, screen capture shots. I assume your included screen shots were thru the full RF/IF systems, right? It would be interesting if you could compare them with your computer monitor screen shots. Seems you have some color analysis contamination in the small detail. Looking forward to your further screen shots.

Tom,

In the link I provided, (within the image carasel) you can click on a tab to see the full resolution shots. I used a non-pro camera, an iPhone 6 Plus to capture the shots. The signal was OTA converted to analogue with a converter box. I'm still planning to adjust a bit more and create a video. I followed your treads on the 21CT55 and that CRT produces about the best color CRT screenshots I've seen from an old "roundie". The original CRT (21CT55) was replaced with a newer tube, right?

etype2
01-22-2017, 05:55 PM
Wow! Wonderful restoration and documentation of the restoration of one of the very most desirable of the milestone color sets!

jr

Thank you very much JR. :-)

Electronic M
01-22-2017, 09:16 PM
I need to refinish the brass around the safety glass. I don't want to remove the glass if possible. Do you know of a good product I can use to remove the patina? I tried Brasso and it had no effect.

That is odd...The same trim was used on the CTC-4, and I polished that trim on my CTC-4 with brasso. Did you forget to shake the bottle before using or forget to scrub?...I had to scrub mine vigorously with a discarded toothbrush to polish the tarnish off.

etype2
01-22-2017, 10:23 PM
That is odd...The same trim was used on the CTC-4, and I polished that trim on my CTC-4 with brasso. Did you forget to shake the bottle before using or forget to scrub?...I had to scrub mine vigorously with a discarded toothbrush to polish the tarnish off.

I tried with a soft cloth. I good try your meathod or maybe a Dremel tool with fine sandpaper, then seal with varnish?

ohohyodafarted
01-23-2017, 12:36 AM
I tried with a soft cloth. I good try your meathod or maybe a Dremel tool with fine sandpaper, then seal with varnish?

The only way to get good results refinishing the brass is to remove the trim and work at it with successively finer grades of steel wool or scotch bright. The brass has a lacquer coating, that was sprayed on at the factory. Brasso will not do anything unless the brass is bare naked. Then Brasso can remove the tarnish. If you try to remove the lacquer coating using Brasso and a soft cloth, you will be expending many needless hours of labor

Removing the brass trim is easy. Behind the crt bezel you will find tensioning clips that hold the trim in place. Remove all the clips that hold the trim tabs in place. Then you can push the trim tabs forward, through the crt bezel and the trim frame can be easily removed.

If you try and clean the trim with Brasso with the trim in place, you will end up with Brasso in all the crevasses, and then there is still the problem of having to apply a new coat of clear lacquer to prevent future tarnish. No, varnish is not the correct product to use.

Click on the "Brass Refinishing" link under "MY Methods" section at my web site or click below

http://antiquetvguy.com/WebPages/MyMethods/BrassRefinishing/BrassRefinishing.html

etype2
01-23-2017, 02:42 AM
Bob,
I found out quickly about the Brasso getting in crevices as well as a soft cloth not working. Thank you for the suggestions.

Kirk
01-23-2017, 08:50 PM
Great Job! Went to your website and saw the pictures....I just started working on my 21CT55 again....you cant beat seeing Spock on a 21AX!

benman94
01-24-2017, 02:11 PM
etype2,
You might consider Bob's method of removing the old lacquer, but instead of using Brasso to polish the brass, use MAAS polish. I do brass instrument repair and restoration (I specialize in higher end pre-war Conns) and MAAS is the polish I always use before either silver plating or hitting the horn with new nitrocellulose lacquer.

etype2
01-24-2017, 03:09 PM
Kirk: Thank you.

Ben: Thanks for the tip. Never heard of it, checked their website, looks like an excellent product. I will give it a try.

benman94
01-24-2017, 03:55 PM
Brasso tends to leave a mottled appearance to the brass, only visible once the lacquer is on it. If you use Brasso before silver plating, sometimes the plating process will fail; you'll get a blotchy uneven finish no matter how you try to clean the Brasso residue. I've never had either problem with the MAAS. You're mileage may vary of course.

Jon A.
01-24-2017, 05:21 PM
etype2,
You might consider Bob's method of removing the old lacquer, but instead of using Brasso to polish the brass, use MAAS polish. I do brass instrument repair and restoration (I specialize in higher end pre-war Conns) and MAAS is the polish I always use before either silver plating or hitting the horn with new nitrocellulose lacquer.
Would that be good for bronze as well? The handle on my Heathkit GR-370 had the most crap I've ever seen on decorative hardware, bar none. It's mostly gone now, but the hardware is still badly tarnished.

benman94
01-24-2017, 05:28 PM
Yes. I've used MAAS on bronze with great success, and even on pure copper (a Conn 12B with the "Coprion" type bell). It works great on silver too, but electrolytic cleaning is always a better first line of attack with silver. At least with electrolytic cleaning you aren't removing any of the underlying plating.

etype2
01-27-2017, 02:33 AM
Here is one more screenshot from my restored RCA 21CT55, captured from last nights tribute program to Mary Tyler Moore who passed away on January 25, 2017. Her show was a favorite of mine which ran from 1970 to 1977.

https://visions4netjournal.files.wordpress.com/2016/12/img_5495.jpg

ceebee23
01-27-2017, 06:15 AM
beautiful image and such a lovely smile... vale MTM ....

sampson159
01-27-2017, 04:22 PM
couldnt have found a better face to look at.beautiful lady and i very nice image on that set.

etype2
01-31-2017, 06:25 AM
Thanks, Mary Tyler Moore will be missed.

Tomcomm: you asked for larger screenshots and a comparison to a computer screenshot. I'm not currently using a computer, just an iPad Air first generation. I have a 2012 Sharp Quatron 70 inch LCD TV/Monitor with full array LED backlighting. One notable feature is that it has 25% more pixels because of the yellow pixel. We had the set calibrated to ISF (Image Science Foundation) Rec. 709 standard three months after purchase in March, 2012. You can see the calibration charts on the "4K" page of my website. I estimate the set has over 29K hours on it. The first photo was captured with an iPhone 6 Plus of the Miss Universe contestant representing France and won the competition on this Sharp monitor. Fox broadcasts 720P not 1080i

1. https://visions4netjournal.files.wordpress.com/2016/12/img_2822.jpg

2. The second photo is the same frame captured with the same phone off my RCA 21CT55. This photo was cropped to remove excess boarders.

https://visions4netjournal.files.wordpress.com/2016/12/img_2799.jpg

3. The third photo is the same image as photo 2, but captured with the iPhone 6 Plus off the Sharp monitor by Apple mirroring.

https://visions4netjournal.files.wordpress.com/2016/12/img_2825.jpg

4. The fourth photo is the same image as numbers 2 and 3 captured as a screenshot from my iPad Air formatted to it's 9.7 inch Retina display. When the iPad Air first came out, Display Mate website ran a test and declared it "the most accurate mobile display" at that time.

https://visions4netjournal.files.wordpress.com/2016/12/img_2823.png

I don't know how "scientific this test is, but one thing for sure is you can see how much of the image is lost on a roundie CRT. I'm still not satisfied with the color on my 21CT55 and further "tweaking" is required.

It appears that the mirrored image lost image detail, etc. but I can tell you the Sharp monitor is very accurate. (See the calibration charts on my "4K" page.) https://visions4netjournal.com/4k/

Continuing .....

benman94
01-31-2017, 11:19 AM
I'm not sure if it's an artifact of the camera, my vision, or both, but I see very little color in the lips on Ms. France.
I also don't see much green in the previous screenshots, but that could be an artifact between the camera, my display, and my eyes.

etype2
01-31-2017, 12:48 PM
Ben,

Yes, that bothers me. On all the screenshots so far, women's lipstick just will not display well. The red is there though. You see it in her hair. I have a screenshot of JoAnne Worley from the Laugh In show in 1969 and her bright red feather boa displays with good red, but it doesn't pop.

On the pattern generator, all three colors look good. More adjusrtment with the color gain controls? Mike said the all three guns tested strong, just not new.

dtvmcdonald
01-31-2017, 01:37 PM
Ben,

Yes, that bothers me. On all the screenshots so far, women's lipstick just will not display well. The red is there though. You see it in her hair. I have a screenshot of JoAnne Worley from the Laugh In show in 1969 and her bright red feather boa displays with good red, but it doesn't pop.

On the pattern generator, all three colors look good. More adjusrtment with the color gain controls? Mike said the all three guns tested strong, just not new.

Don't expect lipstick or other really bright red things to look right in
real scenes.

Several things to check:

1) is your modulator being overdriven? That will do it. Step 2) checks this.

2) check B&W step patterns on all three guns ... be sure the red
one is not seriously overdriven. This will also check 1). I suggest lots
(like 30) of steps.

3) check the fine tuning and IF response with a full-screen horizontal
chirp test (e.g. Digital Video Essentials), with the color control all the way down.
There should not be a dark area where the chirp goes into
the color region (starting at say 2.2 MHz) . If adjustment of fine tuning does not get
a sharp picture (i.e. down more more than 25% at 3 MHz) , good amount of color
(on a color picture), and lack of the dark area, you probably need a full RF-IF alignment.

4) check the setting of the R-Y drive pot by examining the
R-G-B CRT grid waveforms with a scope, at low contrast settings, using
normal color bars. The should show all the bars at only two levels.
Adjust the R-Y pot, color level, and hue until its as good as possible on all three.

5) check adjust contrast and brightness for proper bar appearance
being sure that the red gun is just barely clipping.

6) recheck the gray step pattern to be sure it is uniform color. If
not, readjust screen and video gains. Be sure to check the red screen pot ...
all the way CW may not be best, run through the whole range. Then recheck 5).

I just did this yesterday on my CT-100 and found 6 to be a problem.
The gamma is too high on these CRTs and you may be unable to get
good bright reds and good scene visibility in dark scenes at the same time.

4) can't be reliably done by eye ... you may be setting with too much red clip.
You need a scope.

Repeat until you understand what is going on.

Doug McDonald

etype2
01-31-2017, 02:13 PM
Doug,

1. Not using a modulator, but I plan on purchasing a very good quality modulator, maybe even a pro model. I suspect that my $50. digital converter is degrading the image. I say this because when we were testing on Mike's setup with modulator and DVD the images looked cleaner. I see "video noise" for lack of understanding of what I'm seeing. Also there is a faint vertical band in the center of the screen only visable in dark scenes. The band was not present with the DVD/modulator.

3. We did do a full IF alignment. I think that is why the this 21CT55 displays very good detail. I have a copy of the Video Essentials disk.

I suspect the red gun is being driven to high.

In the end, based on what we saw with the modulator/DVD setup on the bench and what we see with the digital converter now, our next step will be to purchase a high quality modulator so I can view DVD's on this set and go from there. I'm very happy with the image detail though.

Thank you for the excellent testing recommendations. We will follow through.

dtvmcdonald
01-31-2017, 02:42 PM
The Blonder-Tongue BAVM single-channel models are just fine. Yes,
the -SAW ones are better than the -z ones but I can't tell the difference
on any of my TVs. They are very cheap on ebay .. you can buy two or three.

And ... compared to the "agile" ones they run cool as watermelons.
The agile ones run very hot.

Tomcomm
02-01-2017, 08:10 PM
etype 2 I’m very much impressed with your Miniature TV write-up. I was
repairing TVs starting in the seventh grade and bought a 3 inch Pilot TV-37
in 1951 for use as a portable test set on service calls, which my Mom drove
me to. For a junior high school science fair in 1952 I cut the chassis width
almost in half and folded it over to make the “Worlds Smallest TV”, or so
I thought! I still have it in it's crude cabinet and it still works, maybe?

The cabinet modifications of my 21CT55 to make it fit into my new tiny lab
was no big challenge. I replaced the weak 21AXP22 with a 21FBP22A
and made it a composite baseband video only monitor only.

etype2
02-01-2017, 09:13 PM
Doug: Sounds like you see no difference in video quality between the two modulators. Can the Saw models be adjusted for over modulation?

Tom: Got it, you went for the purest signal to the television.

I got started with crystal radios in 1956, 9 years old, then with some help from my genius neighbor 3 years older then myself and already had a radio operators license, we got an old junker vertical console working. It was dumped in the back of a neighborhood TV repair shop. I asked if I could have it and he said it was junk but go ahead and take it. He helped me lift into my coaster wagon.

About the micros, thanks. A lot of them were bought new back in the day. I envite you to send me your favorite television's/projects. I will post photos and your information on my "Viewers Television's" page. The envitation is open to all who reads this.

etype2
02-02-2017, 05:29 AM
The 21CT55 in action in this video.

https://m.youtube.com/watch?feature=youtu.be&v=weuaTgZuIPQ

etype2
02-10-2017, 03:29 PM
After adjusting the color controls on the RCA 21CT55 the past view days, I think we have better color images. I took a slew of screenshots and the full size images can be seen here: https://visions4netjournal.com/vintage-rca-color-tv-page-two-2?iframe=true&theme_preview=true

https://visions4netjournal.files.wordpress.com/2017/02/img_7768.jpg

https://visions4netjournal.files.wordpress.com/2016/12/img_3090.jpg

https://visions4netjournal.files.wordpress.com/2016/12/img_3089.jpg

https://visions4netjournal.files.wordpress.com/2017/02/img_7771.jpg

https://visions4netjournal.files.wordpress.com/2017/02/img_7766.jpg

https://visions4netjournal.files.wordpress.com/2017/02/img_7767.jpg

Tom9589
02-10-2017, 06:28 PM
Your screen shots look great! Too bad you included some screen shots of Trump. This is not a political forum.

etype2
02-10-2017, 06:46 PM
Your screen shots look great! Too bad you included some screen shots of Trump. This is not a political forum.

Thank you for the compliment. Never intended the post to be political. If it makes any difference, we posted a screenshot of President Obama on the 21CT55 on my website. Equal time.:thmbsp: No affiliation either way.

sampson159
02-10-2017, 08:49 PM
equal time is right.i wasnt offended by a screen shot of our president.that set looks fantastic!i remember seeing these sets when they were on display back then.the colors were vibrant and alive!thrilling to see.beautiful set and thanks for posting thoise pictures

Electronic M
02-10-2017, 08:54 PM
Many who had a hard time putting up with the last guy, can't help but smile and laugh at those that can't manage to put up with the current guy. :D Reversals can be refreshing, and enlightening!

benman94
02-10-2017, 09:48 PM
I didn't vote for either of those idiots. Clinton and Trump are both terrible people; you have to be in order to get involved in politics. That said, he is our president and I don't see how posting a screenshot of the inaugural is political. We're going to be seeing too damn much of the man, better buckle up and get used to it now.
Also, from the interaction I've had with etype2, I doubt very much this was a political statement one way or another.

etype2
02-10-2017, 11:01 PM
I apparently offended at least one member so I removed the photos in question. I really never thought of the photos as being political, but I can see how someone might think that. To me it was an historical moment and for my own use, I wanted to preserve that moment, live as it happened.

I would very much prefer comments on the screenshots as captured from a 62 year old color television.

Kevin Kuehn
02-12-2017, 12:14 PM
The set appears to be working wonderfully, and your excellent photography skills have captured it in all it's splendor. :thmbsp:

Hagstar
02-19-2017, 09:57 AM
The WORST political posts are the False Equivalence ones where everyone is viewed as the same. Never thought we'd have to bear such here.

etype2
02-19-2017, 01:05 PM
Thanks Sampson 159.

Thanks Kevin. Still not satisfied with the green, better but working on it.

With no ability to freeze the images at the moment, I just click away and the majority have movement, blurry, etc. A few shots come out okay.

benman94
02-19-2017, 01:48 PM
The WORST political posts are the False Equivalence ones where everyone is viewed as the same. Never thought we'd have to bear such here.

etype2 asked us to keep the posts related to the set itself, and most of us have since he asked. You might give it a try...

etype2, the green still looks weak to me, but it could be something about your camera, my monitor, or my eyes. Color vision is a surprisingly difficult thing to describe in a very general, quantitative way. Regardless, the set is 99% there. Very, very nice set; I'm green with envy

etype2
02-19-2017, 02:33 PM
Thanks Ben. :thmbsp: It's not your eyes, the green is not vibrant. The flower shot with the butterfly is about the best so far. It depends on the program. Technicolor seems to look the best. The green gun has good emission. I'm working on improving it.

Edit: Adding. The green glass oil lamp behind Robert Mitchum in El Dorado, should look more vibrant. More often then not palm trees look more gold then green. Have to improve this.

Electronic M
02-19-2017, 06:13 PM
Lack of green really gives it that "tan cowboy, riding the brown horse into the orange sunset look"...Of course I tend to set up my sets so the blacks favor a mild green tint and the greens are strong and vibrant....When I watch a show with green grass in the winter I want to believe I'm looking at the fresh emerald green grass of spring. :D

etype2
02-19-2017, 06:59 PM
Lack of green really gives it that "tan cowboy, riding the brown horse into the orange sunset look"...Of course I tend to set up my sets so the blacks favor a mild green tint and the greens are strong and vibrant....When I watch a show with green grass in the winter I want to believe I'm looking at the fresh emerald green grass of spring. :D

Tom,

I understand that point of view. Having lived in Wisconsin the first 33 years of my life .... in winter, the shades of grey and cabin fever. NO GREEN! :D

dtvmcdonald
02-20-2017, 11:11 AM
Its not just a lack of green. Its also a lack of magenta/violet.

This simply means that the I/Q or rather R-Y/Q balance is off seriously.

Look at the SPECIFIED type color bars with your scope and adjust per instructions. Alternatively, use R-G-B-Yellow-Cyan-Magenta bars and
adjust so bars containing a given primary all have the same height at
the CRT grids ... see CT-100 scope traces. Pay particular attention
to the R-Y gain, its non-intuitive.

If this fails, you have matrix resistor issues.

etype2
02-20-2017, 12:04 PM
Thank you dtvmcdonald.

"Its not just a lack of green. Its also a lack of magenta/violet."

What leads you to this conclusion?

dtvmcdonald
02-20-2017, 12:12 PM
Why too little magenta? First, cartoon characters tend to have lots of magenta and
violet ... the designers like the whole rainbow. Yours do have a rather drab violet. Second, the overall "look" is the
same as when my CT-100 (pre red gun illness or even now at low brightness)
is misadjusted with the wrong I (or R-Y) gain setting.

etype2
02-20-2017, 01:19 PM
Doug,

Okay, that is good to know. We will look into it. I would still like to see some screenshots of your CT-100 prior to the red gun problem, or direct me to the thread where you posted the shots. Thanks.

etype2
02-22-2017, 05:27 PM
Here are a few shots displaying magenta, purple and green on my 21CT55. They were captured yesterday on February 21, 2017 from an OTA broadcast on Decades TV of the 1955 Technicolor movie, "Gentlemen Marry Brunettes". The movie is showing its age in terms of quality but this is my magenta and green presently. Of course it varies from program to program.

https://visions4netjournal.files.wordpress.com/2016/12/img_3461.jpg

https://visions4netjournal.files.wordpress.com/2016/12/img_3441.jpg

https://visions4netjournal.files.wordpress.com/2016/12/img_3445.jpg

Edit: I found this screenshot from a remastered CD shown on a modern television. Apparently my green is not to far off from what it should be.

https://visions4netjournal.files.wordpress.com/2016/12/img_3479.jpg

https://visions4netjournal.files.wordpress.com/2016/12/img_3448.jpg

dtvmcdonald
02-22-2017, 07:55 PM
Doug,

Okay, that is good to know. We will look into it. I would still like to see some screenshots of your CT-100 prior to the red gun problem, or direct me to the thread where you posted the shots. Thanks.

See attached pictures. The cartoons and girl with hat are off the air

Test pattern is RGB
+I -I +Q -Q

My avatar is also the CT-100

etype2
02-22-2017, 08:25 PM
Thanks for posting this. The red in Dorthy's lips is "redder" then my same screenshot. The girl with the hat shot, was that prior to your red gun problem? Looks well balanced.

Note: The first shot in my last post was done with the tint control set for overall best flesh tones on a majority of OTA programs. When I saw the dresses, I assumed they were magneta. It's possible that the dresses are really red.

benman94
02-23-2017, 09:51 AM
Might I make a suggestion, etype2?

Post some screenshots from the Eisenhower tape and "An Evening With Fred Astaire". Download the higgest quality copies from say YouTube and burn it to a DVD or stream it via a media server and STB to your 21-CT-55. Those are "known quantities", whereas a Technicolor film could have been sourced from an IB print, the negatives, an Eastman print, etc. Then there's the issue of color correction. For example, there are DVD copies of "The Wizard of Oz" that are sourced from an IB print, and at least two versions sourced from the negative scans but color corrected differently. If you use the Eisenhower tape though, we can all look at the YouTube clip and compare that to the screenshots. It's one less variable to contend with.

Just an idea.

etype2
02-23-2017, 02:41 PM
Ben,

I have watched both programs on YouTube. Thankfully Chris Trexler has preserved the entire Fred Astaire special complete with commercials in one clip for all of us to enjoy and many thanks to the late Ed Reitan and his colleagues for restoring the Astaire tape in the first place.

What is STB? Your suggestions are good ones. BTW, We were lucky to win Ed Reitan's Worthington CTC-7 several years ago at the ETF convention. The Worthington first introduced in 1958 was the same year as the Astaire special. We would like to pay tribute to Ed Reitan and play that special on his set, (We are just the custodian for now) then make a video of our own and publish it on YouTube.

So yes, we would very much like to take up your suggestions. Thanks.

benman94
02-23-2017, 03:10 PM
STB= set top box

You can use a Raspberry Pi with an XMBC-centric distribution as a set top box. Then run an XMBC server and stream the data over your network. Or, just burn the videos to a DVD and play them back through a decent DVD player connected to a decent RF modulator.

The XMBC solution is more elegant though because you can turn the actual color burst on and off, etc. Much better for diagnostic purposes. And it requires only the use of your existing network, either wired or wireless. Fewer coax cables strung about.

Both specials would make subjectively "better" programming for comparison purposes in my opinion. I don't know how "The Wizard of Oz" became a sort of pseudo-standard for demonstrating early color sets, but I wish it hadn't. Other, better, options exist.

miniman82
02-23-2017, 05:51 PM
We were lucky to win Ed Reitan's Worthington CTC-7 several years ago at the ETF convention. The Worthington first introduced in 1958 was the same year as the Astaire special. We would like to pay tribute to Ed Reitan and play that special on his set, (We are just the custodian for now) then make a video of our own and publish it on YouTube.

I'll be doing nearly the same thing with his Gilfillan prototype, if and when I ever get around to making it work.

dtvmcdonald
02-23-2017, 08:12 PM
The correct method for comparing color rendition is as follows.

It requires a modulator and a box, usually a Blu-Ray player, that will
play from memory sticks.

1) Obtain suitable jpg file of subjects that illustrate want you think matters.

2) copy those to your memory stick.

3) play them to your TV.

4) take pictures of the TV

5) transfer the pictures to the computer the files came from

6) one at a time, open the pictures of the TV in a photo editor
on the computer. At the same time, have the picture showing on the TV,
set just as it was when taking the picture.

7) edit the photo on the computer until it looks just like the TV
(that is, the image on the computer screen looks like the TV)

8) save the edit picture.

You then upload both the original picture you played on your TV
and the edited picture you took off the TV

Because you edit the picture of the TV on the computer to match the TV,
if you show the original and the TV picture on the same computer,
you will see the difference the TV made. This will also be true
of doing the comparison on ANY computer since you will have the
two files to compare.

There are three pairs of pictures made using this method
here:

http://videokarma.org/showthread.php?t=262176&page=6

One of them is three bicycles, another is purple flowers.

I've attached images of a standard test pic.

Doug

etype2
02-23-2017, 09:44 PM
Doug,

Thank you for this great step by step explanation. I now get it. I resisted you in the past because I misunderstood what you were saying. You were talking about Photoshop and I heard manipualation. Manipulation to me is photo editing to make the photo look better then it was and that's still true. In the context of what you are now saying it's not manipulation. I don't have a computer at the moment, so I'm using an iPad Air.

In my post#50 above, photos 3,4 and 5, is in a way the same test, but we did it backwards. We took all photos first. Then we got the idea to see if we could see pristine photos of the same movie. By luck and pure chance, we found a near identical pristine widescreen screenshot of my image #3. You can see it comes close to the original pristine photo but the roundie 21CT55 cuts off almost 50% of the image! If We had the pristine photo first, we could have adjusted the saturation a bit lower on the 21CT55.

I'm hearing rumors of a new iMac coming soon to replace a now two year old model. We will purchase at that time. We moved to a new home last May and we didn't bother hooking up the old PC because it's too slow.

benman94
03-01-2017, 06:23 PM
Just an FYI for anyone interested, I downloaded the highest resolution copies of the Edsel Show tape, the WRC tape, and an evening with Fred Astaire from Youtube. I then used some light denoise, corrected an issue in the WRC tape chroma, scaled it down with a top notch scaling algorithm, reencoded/remuxed it to a DVD compliant TS stream (2 pass, VBR), built a little DVD menu for it, and have the ISO for anyone interested.

It still looks like sh*t on a flat panel (like most SD material) but looks very nice on an analog set. Short of getting access to the whatever Ed Reitan and co. dubbed the specials to when they played back the tapes, my lightly cleaned copies are probably the best looking out there.

If you want it, PM me.

Kevin Kuehn
03-01-2017, 07:02 PM
I think ya'll are way over thinking this. Just adjust the set so it's a respectable representation of the colors as you see them in nature, and boom you're done. :D

etype2
03-01-2017, 07:47 PM
Just an FYI for anyone interested, I downloaded the highest resolution copies of the Edsel Show tape, the WRC tape, and an evening with Fred Astaire from Youtube. I then used some light denoise, corrected an issue in the WRC tape chroma, scaled it down with a top notch scaling algorithm, reencoded/remuxed it to a DVD compliant TS stream (2 pass, VBR), built a little DVD menu for it, and have the ISO for anyone interested.

It still looks like sh*t on a flat panel (like most SD material) but looks very nice on an analog set. Short of getting access to the whatever Ed Reitan and co. dubbed the specials to when they played back the tapes, my lightly cleaned copies are probably the best looking out there.

If you want it, PM me.

I'd be interested. Can you burn a DVD? Will send you a private message.

I uploaded two additional videos to YouTube.

First: https://youtu.be/EOKXCV35q7Y

About all the movement. I was not that shaky. We used a stabilization upgrade in YouTube Capture and it made the video much worse then original. The video is a bit over saturated.

Second: https://youtu.be/21DrJUTek6Q

This video was done to show the entire cabinet. Choose 1080p or 720P

Kevin Kuehn
03-01-2017, 08:28 PM
I think your set looks great. However everyone's perception of color rendering is varied, just we all hear things differently.

etype2
03-01-2017, 10:49 PM
I think your set looks great. However everyone's perception of color rendering is varied, just we all hear things differently.

Kevin,

Thank you. Absolutely!

We have found through the years, it depends on program material. Some of it is good, some not so good. Looking at programming, especially the nostalgic stuff today, the video color quality varies from very good to poor. The same series can look great one night, the next night, not very good because the stations are broadcasting episodes which can be years apart, night to night. We are disadvantaged at the moment without the ability to display DVD content. We know the quality of DVD content on an old roundie is better then converted OTA broadcasts generally speaking, there are exceptions.

I feel very satisfied with the results of our restoration. I think we got it as good as we can knowing the limitations of 62 year old technology. Yet there is always that quest to get it better. I appreciate all the VK members that helped in our restoration, including you Kevin. Stay tuned. :-)

Electronic M
03-01-2017, 11:26 PM
Out here you can get a DVD player and a RF modulator for under $10 at thrift stores....The local Goodwills have 5-20 DVD players for sale on any given day. Drop in and grab a cheap used one.

benman94
03-02-2017, 01:21 PM
Out here you can get a DVD player and a RF modulator for under $10 at thrift stores....The local Goodwills have 5-20 DVD players for sale on any given day. Drop in and grab a cheap used one.

Hell, the last time I was in a Walmart, which has been a while, they had a cheapo DVD player on sale, new, for $15 or so.

I'd recommend using a BT modulator though.

etype2
03-02-2017, 02:30 PM
Ben,

There was a problem with the private message, so I sent you my reply by email with address. Thanks very much.

Tom: I have several DVD players, need a good modulator.

Electronic M
03-02-2017, 03:49 PM
Hell, the last time I was in a Walmart, which has been a while, they had a cheapo DVD player on sale, new, for $15 or so.

I'd recommend using a BT modulator though.

The BTs are great performers.:thmbsp: Though the number of BTs that need a recap is unsettling for a SS product.

You can pick up a BT BAVM-z on ebay for well under $50. I recommend the fixed channel BAVM series over the AM40/60 mods. The BAVMs seem to run cooler and have a lower DOA percentage when buying un/partially-tested units....Make sure you pick one set up for a channel your set can tune, and that you want to use. The BAVM series can transmit up to a few hundred feet (about a block) if feeding a dipole ant cut to the 1/2 wave wavelength of the channel's center frequency....If you choose to go the wireless route (as I have) I recommend selecting a channel not used by any tuneable local DTV stations...If you pick a active local channel you'll interfere with those close by trying to tune the DTV station and the DTV station will interfere with you.

etype2
03-02-2017, 04:15 PM
The BTs are great performers.:thmbsp: Though the number of BTs that need a recap is unsettling for a SS product.

You can pick up a BT BAVM-z on ebay for well under $50. I recommend the fixed channel BAVM series over the AM40/60 mods. The BAVMs seem to run cooler and have a lower DOA percentage when buying un/partially-tested units....Make sure you pick one set up for a channel your set can tune, and that you want to use. The BAVM series can transmit up to a few hundred feet (about a block) if feeding a dipole ant cut to the 1/2 wave wavelength of the channel's center frequency....If you choose to go the wireless route (as I have) I recommend selecting a channel not used by any tuneable local DTV stations...If you pick a active local channel you'll interfere with those close by trying to tune the DTV station and the DTV station will interfere with you.

Definitely wireless. Then I can operate my micros around the house and my three other roundie's.

Is it best to choose a lower channel or a higher one? Any advantages either way? You are the third person to recommend BT.

benman94
03-02-2017, 04:22 PM
It really doesn't matter. Back in Michigan I had a setup that broadcast on channels 2, 4, 7, 9, and 12.

Back in the stone-age, Detroit was 2, 4, and 7 on VHF, Windsor was 9, and Flint was 12.

Electronic M
03-02-2017, 04:44 PM
I've found 2 tends to have a bit less maximum range than all others, and 7 tends have the best range on VHF*...Both covered my whole house and grounds, and then some with no signal strength issues.

*It may be my antenna's...I followed Shango66's youtube video on making antennas, but I lack the IIRC VSWR meter he has so all I can do is grind the math, and cut off the same percentage of length as he did...IIRC from my college antennas elective if you want to change the effective impedance of a dipole at a frequency you can do it as a percentage of length, and it will hold for dipoles of other freqs as long as the impedance change is the same and the percentage is the same....At any rate my work is in the right ballpark to function decently, and that is what matters to me.

I've not set up a UHF BT rig, but have been wanting to get to that for a while now...

benman94
03-02-2017, 04:57 PM
I loathed "traditional" E&M in my undergrad, so I'm afraid I wouldn't be of much help with the antennas. My area of study has primarily been medical imaging (MRI, PET, X-ray, CAT, etc), with brief forays into electrophysiology of cardiac tissue and a purely mathmatical treatment of disease transmission (HIV) in a population. Hyperbolic sines and cosines show up in the weirdest places...

etype2
03-02-2017, 05:23 PM
I'm into the best quality possible and don't mind spending extra to get the best. (Retired and want to enjoy the fruits of my labor, maybe 12-15 years left) I would imagine hard wired offers the best video quality, but would be an inconvience and I would loose the ability to use my micros wirelessly. I recall reading about or seeing on YouTube that some had problems with over modulation and someone recommended getting a modulator with adjustable modulation feature.

Our home is one story, 2200 sq. feet on over one third acre. I don't care about going beyond our home, but want the best quality so should I get the higher power models anyway? Will I see a degradation in video quality with wireless as compared to a direct connect to the roundie with a good quality DVD player? Edit: I guess there is not any easy way to connect a DVD player without a modulator?

benman94
03-02-2017, 05:34 PM
You can build an adapter to feed the 21-CT-55 composite video from the DVD player and bypass the RF/IF sections entirely.

Electronic M
03-02-2017, 06:20 PM
BT mods over the air can produce about as good quality as commercial NTSC broadcast did....There are some pit falls to avoid in order to achieve maximum quality. Ground loop hum is a big one. My mods are powered off an isolation transformer so I don't have to worry about the ground level in all the different gear in my A/V sources racks not playing nice with the grounding in the BT cord and PS.
A good TX antenna is essential (an average RX antenna is useful). Shango66 has a good video youtube video on making a TX antenna that I can find for you later if you want. Good TX antenna placement is important (that is trial and error). In setting up the TX an 80's or newer portable TV set can be very useful in checking signal strength, quality and range.
Setting the video and audio levels for no over modulation is important...Start at zero, crank till the over mod lights come on then back off till they stay near constantly out.
Buying a modulator in good shape (or having it repaired) is important. Many have bad lytic caps and such bad power supply hum that you can ground the input terminal to the chassis and the over modulation lights will still come on.
Also be mindful that large pieces of metal or other highly RF reflective objects in your home (other than the TV) may cause multipath reception issues.
If you do all that right and use an empty channel to send all should be good with an hour or two of experimenting with the initial set up.

BT mods can be fun to play with and set up if you, do it right, and know enough about troubleshooting.

All BT modulators I've seen have RF output level control. Also, I've got AM60(strongest RF), BAVM(middle), AM40(weak) and all are capable of sending at least 100' wirelessly with a decent TX antenna.

etype2
03-02-2017, 07:13 PM
Thanks for the advice, both of you. We will try a modulator first and see how that works out. Checking them out now.

I think Tomcomm did the adaptor to bypass RF/IF. Interesting.

benman94
03-02-2017, 08:07 PM
Thanks for the advice, both of you. We will try a modulator first and see how that works out. Checking them out now.

I think Tomcomm did the adaptor to bypass RF/IF. Interesting.

He did. It's a very simple chassis, but sort of "cheating". I would personally use a BT modulator hardwired to your sets, but that's just my preference. I can echo Tom in that channel two seems to be weaker, but I usually got better performance with higher channels, thus 12 was strongest, followed by 9, 7, 4 then 2.

etype2
03-12-2017, 05:31 PM
Yesterday, we pulled an old good quality Sony DVD player and found a cheap Radio Shack wired RF modulator in my pile of stuff. No wireless purchased as yet. Popped in the Wizard and got very good results. The obligatory Dorthy shot now has less of a blue cast and very good geometry.

Several more shots within the movie were captured. This time I had freeze frame and I could set each individual capture exposure by eye to match what we were seeing on the screen. The camera is an iPhone 6 Plus. The green is improved but could be better. We are working on that. I didn't want to take up a lot of space with the shots on this forum, but you can see full resolution shots on my site.

https://visions4netjournal.files.wordpress.com/2016/12/img_4098.jpg

https://visions4netjournal.com/vintage-rca-color-tv-page-two-2/

etype2
03-29-2017, 04:18 AM
We have green! and a new “Dorothy” reference screenshot.

So we went out and purchased the old version of Joe Kane’s Video Essentials on DVD. We have the Blu Ray version, but it was not compatible with my current DVD player hooked up to the 21CT55. Using the supplied blue filter film, we calibrated the blue gun of the 21AXP22. If the color decoder is working correctly, the other two colors should “fall into place”. Our green gun was not displaying green as well as it should and in our latest adjustment/calibration, we took a different approach. This time instead of increasing the green gain, we decreased the green gain and increased the green background controls to get proper color balance on the SMPTE-C color bars displayed by the DVD. This greatly improved the green reproduction on the various programming we viewed after the calibration.

We tested using the Wizard of Oz, The Red Shoes and Gentlemen Prefer Blondes, all great Technicolor films. The recently discovered Red Shoes film from 1948 is a gem of a movie to evaluate an old color roundie television. The color is simply beautiful and there is one scene in particular that replicates the standard “Dorothy” facial shot from the Wizard of Oz which many collectors use to judge their televisions. The color tones and gradations are superior in this authors opinion. The scene we are referring to is the lead actress in the film. We will be using this movie, The Red Shoes, to evaluate current and future color televisions in and for our collection. Below, the first screenshot is what we call the “new Dorothy reference screenshot” and additional screenshots from the three movies. The scenes have more depth and look less flat now that we have good green reproduction. We still see color decoder errors, but Marilyn’s pink (a difficult color to reproduce) satin dress is reproduced reasonably well for a 62 year old television and it’s technology. Trees, shrubbery and scenic scenes now have good green color reproduction. Full resolution screenshots can be seen here: https://visions4netjournal.com/vintage-rca-color-tv-page-two-2/

Very large page. Scroll to bottom for latest update. You need a medium to fast internet speed to view. 20mbps.

https://visions4netjournal.files.wordpress.com/2016/12/img_4417.jpg

https://visions4netjournal.files.wordpress.com/2016/12/img_4484.jpg

https://visions4netjournal.files.wordpress.com/2016/12/img_4485.jpg

https://visions4netjournal.files.wordpress.com/2016/12/img_4486.jpg

https://visions4netjournal.files.wordpress.com/2016/12/img_4487.jpg

https://visions4netjournal.files.wordpress.com/2016/12/img_4488.jpg

benman94
03-29-2017, 06:19 AM
Some of us have been using "The Red Shoes" all along... not exactly a newly unearthed film. Good luck getting anyone else to use it for reference shots. :lmao:

Green does look much better though, etype2.

old_tv_nut
03-29-2017, 04:03 PM
"The Red Shoes" has some very nice color, making it a good demo piece, but IIRC, does not have the variety of greens and yellows that Oz has. (I don't have a copy to verify that, but I saw the restoration release at a SMPTE meeting a few years back.)

Use of Oz reminds me of the stereo hi-fi engineers at Motorola in the 60s, who used Tijuana Brass records for testing, not because they had the most beautiful music, but because they had instruments in every frequency range.

old_tv_nut
03-29-2017, 04:07 PM
Oh - I forgot to say NICE results! Marilyn's magenta-pink dress is a particularly difficult item to keep right.

etype2
03-29-2017, 04:21 PM
Ben: Thanks and to your comment. I read a few reviews of The Red Shoes and wanted to see it for myself, so I just saw the movie for the first time recently.

Wayne: Thank you. I agree, The Red Shoes is subtle in color application and Oz does have a wide range of colors. I think the color gradation of Shoes, for lack of a true technical color description on my part looks very good to my eyes. I read that Natalie Klamus objected to adding color in movies just for colors sake. She wanted things "refined" in color films. Those are her words, not mine.

Edit: In Oz, at the early part of the film, when the witch goes to the shed for the first time and then turns back, I see about 2 seconds where it looks like they forgot to restore the film in my copy. It looks very dark and blurry. Can anyone confirm that?

In Shoes, there is one scene where the ballet dancer overhears a conversation at the train station. She is behind a black lace veil and her nose looks grey and unnatural, but the rest of her face looks very good in terms of color. I got the impression it's a flaw in the restoration and they did not catch it.

benman94
03-29-2017, 04:58 PM
Edit: In Oz, at the early part of the film, when the witch goes to the shed for the first time and then turns back, I see about 2 seconds where it looks like they forgot to restore the film in my copy. It looks very dark and blurry. Can anyone confirm that?

In Shoes, there is one scene where the ballet dancer overhears a conversation at the train station. She is behind a black lace veil and her nose looks grey and unnatural, but the rest of her face looks very good in terms of color. I got the impression it's a flaw in the restoration and they did not catch it.

This is precisely why, for comparison's sake, bars or a color videotape can't be beat. There are too many variables when restoring a Technicolor film; each restoration, each print, each DVD/Blu-Ray/LD release will look slightly different. The nicest "Wizard of Oz" I have, in terms of color timing, is on a CAV LD. It was sourced from a then-surviving, now-lost, 1939 35mm print. It has the very dense look that projected IB Technicolor prints exhibit.

It's hard to say what you're seeing on the digital restorations.

benman94
03-29-2017, 05:04 PM
"The Red Shoes" has some very nice color, making it a good demo piece, but IIRC, does not have the variety of greens and yellows that Oz has. (I don't have a copy to verify that, but I saw the restoration release at a SMPTE meeting a few years back.)

Use of Oz reminds me of the stereo hi-fi engineers at Motorola in the 60s, who used Tijuana Brass records for testing, not because they had the most beautiful music, but because they had instruments in every frequency range.

That's a nice analogy Wayne; "The Wizard of Oz" is like one of those hokey stereophonic demonstration records from RCA, whereas "The Red Shoes" or "Meet Me In St. Lois" or even "DuBarry Was a Lady" are like a good recording of a Mahler symphony or a Neruda concerto.

It's not terribly intuitive to understand initially (at least it wasn't for me), but in general, I have found that the gaudier the color, the worse the set can perform before I notice. Very subtle color, relying more accuracy in the color sections, can be terribly difficult to get correct on a vintage set. This is why I prefer "The Red Shoes"; any pile of garbage can make "The Wizard of Oz" look passable, whereas "The Red Shoes" is a veritable workout for the color demod sections.

old_tv_nut
03-29-2017, 05:04 PM
...
Edit: In Oz, at the early part of the film, when the witch goes to the shed for the first time and then turns back, I see about 2 seconds where it looks like they forgot to restore the film in my copy. It looks very dark and blurry. Can anyone confirm that?

In Shoes, there is one scene where the ballet dancer overhears a conversation at the train station. She is behind a black lace veil and her nose looks grey and unnatural, but the rest of her face looks very good in terms of color. I got the impression it's a flaw in the restoration and they did not catch it.

I don't see anything unusual in the scene where the witch first approaches the house and says "Who killed my sister?" But when she goes back to get the slippers and turns to say "They're gone!" the lighting is much harder, her costume is very dark with almost no detail, and the house is very out of focus. This appears as if it may have been a process shot (the house an image on a rear-projection screen) for some reason. I wonder if the original shot was no good and they had to recreate it later after the set was struck.

A note on the Red Shoes restoration. If you could see the original prints they had to work with, you would not believe it. Every frame had mold splotches and damage that looked like water puddles, and variable fading from frame to frame. During the showing, Warner Bros. of course did not give details of their software, but they did indicate it took months of work by hundreds of people directing the operation of the software by eye. Does the DVD have a special feature on the restoration? I'm heading off to smile.amazon to order a copy.

old_tv_nut
03-29-2017, 05:08 PM
... "The Red Shoes" is a veritable workout for the color demod sections.

I would say rather it's a workout for the gray scale tracking and CRT color purity. When we demo these old sets today, we actually have a better chance of good pictures, because all the gray scale and shading problems that often cropped up in tube broadcast gear are non-existent in modern restorations.

benman94
03-29-2017, 05:17 PM
I would say rather it's a workout for the gray scale tracking and CRT color purity. When we demo these old sets today, we actually have a better chance of good pictures, because all the gray scale and shading problems that often cropped up in tube broadcast gear are non-existent in modern restorations.

That's fair. That said, I've found matrix issues to be MUCH more noticeable with very subtle color.

I've seen tape from a TK-26; it was... interesting looking, to say the least. :puke:

Even the Astaire and Eisenhower tapes reveal a lot of issues that would probably have gone unnoticed by the average viewer at home.

old_tv_nut
03-29-2017, 05:34 PM
One thing to add: although the variations in the video gear are gone in modern copies, many Technicolor movie videos still have color "breathing" - the color balance changing slightly and somewhat randomly over a time frame of a second or so. The DVD of "DuBarry Was a Lady" that I have has that and color registration that changes from scene to scene and also is not the same everywhere in the frame. The variable registration is often not noticeable on top of minor convergence issues on an old set, but is very visible if I view the disc on my flat screen.

Warner Bros. is now capable of restoring the color registration to better than what could be achieved in the Technicolor printing process, even when the negatives were new and had not shrunk. As a result, they discovered in "Robin Hood" that Maid Marian's costume had gold threads woven into the fabric, which were obscured in all previous prints.

etype2
03-29-2017, 05:57 PM
I lean to the subtle and well considered color mastering. Interesting analogies drawn, remembering "ping pong stereo" demo vinyl disk. Herb Albert and the Brass, yes bought all his releases.

Wayne, you are seeing what I tried to describe in the Oz scene and in the Shoe scene, it may possibly be the film was so damaged where her nose was and totally destroyed.

Yes there is a nice presentation booklet with two disks. It's available in DVD and Blu Ray. I bought the DVD version so I cold play it in my pre Blu Ray era DVD player. Watching the Shoes on a calibrated flat screen is a real treat, a must have DVD and makes the old roundie look good. Buy the Criterian collection version.

Dave A
03-29-2017, 08:31 PM
Another overlooked Technicolor movie is Kiss Me Kate (1953). A full spectrum of colors in the stage dance sequences and darker colors in the off-stage scenes. And a fun movie. Two pix below.

And honorable mention also goes to The Life and Death of Colonel Blimp (1947) from the same Powell/Pressberger that produced Red Shoes. It is British Technicolor which is just different to me. Not sure what they did differently.

benman94
03-29-2017, 08:44 PM
...Not sure what they did differently.

One woman is responsible for the difference: Natalie Kalmus.

While she technically was the "color consultant" for Technicolor here in the US, she was largely ignored by American directors and cinematographers. Virtually everyone who came in contact with her hated her. George Cukor had terrible things to say about her, and is known to have ordered her off the lot on at least one occasion, Victor Fleming loathed her, etc If you wanted to shoot in Technicolor, you had to put up with Natalie.

Herbert Kalmus eventually started sending her over to "help" the Brits, mostly in an effort to get her out of his hair. They seemed to have actually taken her suggestions. Dare I say the British IB Technicolor looks better? She may have been an enormous b*tch, but she wasn't stupid. The more subtle color works.

Edit:

A few other great films for color roundie demonstrations:

La Cucaracha (1934) *Just a short
The Garden of Allah (1936)
A Star Is Born (1937)
For Whom The Bell Tolls (1943)

And the following all shot by Freund:

Blossoms in the Dust (1941)
This Time for Keeps (1947)
South of St. Louis (1949)
Montana (1950)

Dave A
03-29-2017, 09:41 PM
I forgot about Natalie. She was still around for Blimp and opened the Technicolor office in England but gone by Kate. Ironic that she lasts in our world as a badge on a BW set. Karma is for real.

Pete Deksnis
03-31-2017, 06:28 PM
Edit: In Oz, at the early part of the film, when the witch goes to the shed for the first time and then turns back, I see about 2 seconds where it looks like they forgot to restore the film in my copy. It looks very dark and blurry. Can anyone confirm that?

Just now catching up with his thread. It's been years now since I heard an explanation for the 2-second 'fuzz' scene in Oz. It seemed plausible then, and I have always accepted this -- albeit now sketchy -- explanation. It simply was 2-seconds that had been recovered from a crappy old 16-mm print found somewhere in Europe . Again, details may suffer, so if this sparks a recollection, please update.

Pete

Pete Deksnis
03-31-2017, 06:36 PM
It's my understanding that the only reason Natalie had any Technicolor 'power' was because it was won in a divorce settlement.

Pete

old_tv_nut
03-31-2017, 07:29 PM
It's my understanding that the only reason Natalie had any Technicolor 'power' was because it was won in a divorce settlement.

Pete

Yes, according to books on the subject, the divorce was kept secret. She was such a thorn in one director's side that she was told her expertise was needed in England to get her out of the US for a while.

benman94
03-31-2017, 07:40 PM
Dr. Kalmus and Natalie weren't divorced until the 40s though, despite having been separated since the 20s. Why then would she have been a "color consultant" for everything between the separation and the actual divorce? Does anyone know what exactly the nature of their relationship was for those 15-20 some odd years?

old_tv_nut
03-31-2017, 07:40 PM
Just now catching up with his thread. It's been years now since I heard an explanation for the 2-second 'fuzz' scene in Oz. It seemed plausible then, and I have always accepted this -- albeit now sketchy -- explanation. It simply was 2-seconds that had been recovered from a crappy old 16-mm print found somewhere in Europe . Again, details may suffer, so if this sparks a recollection, please update.

Pete

I just tried looking at the DVD in still frame mode. Unfortunately, the data rate must be somewhat low in order to get the special features on the disc. This means that the grain doesn't show very well, and comes and goes in blocks of artifacts. So, I looked at the Blu-ray version. The Blu-Ray shows the grain in all its glory, and it doesn't seem to change character on her face in that shot. (By the way, I am surprised at how much grain is in the highlights, as I thought most photographic processes are grainiest in the mid-tones.) Also, when she holds her head still momentarily, there seems to be full resolution in her features including the catchlights in her eyes. Her costume is a bit darker than in the surrounding scenes, but I think that's due to the oblique lighting also (the whole movie looks darker on the Blu-Ray than on the DVD on my setup).

So, to my eyes, it still looks like a process shot with very oblique lighting to prevent shining on the rear projection screen.

old_tv_nut
03-31-2017, 07:55 PM
Dr. Kalmus and Natalie weren't divorced until the 40s though, despite having been separated since the 20s. Why then would she have been a "color consultant" for everything between the separation and the actual divorce? Does anyone know what exactly the nature of their relationship was for those 15-20 some odd years?

According to the book "Glorious Technicolor", they were divorced in 1921 but continued to share homes on both coasts. It says that Dr. Kalmus considered her to be a guest, but she acted as a hostess and insisted on being called Mrs. Kalmus. The unusual relationship was ended by written agreement in 1946 involving cash, continuing alimony and a pension from Technicolor. She had taken him to court repeatedly since 1921 trying to get the divorce nullified, and continued suing him into the 1950s regarding community property and trying to get more of the Technicolor fortune. The book also states that Dr. Kalmus, the perfectionist, was in favor of Natalie's work as head of the color consulting department.

old_tv_nut
03-31-2017, 08:09 PM
I would note also that the closeup had to be shot separately and out of sequence in any case, because there are Munchkins lying about her feet in the wide shot.

old_tv_nut
03-31-2017, 09:51 PM
Additional from
http://oz.wikia.com/wiki/Margaret_Hamilton

You may recall that Margaret Hamilton was burned during the exit scene because the flames started before she was completely below the floor. This happened on December 23 1938. She was not able to return to work until February 10.

It's quite possible that the close-up was filmed after February 10, and either the set had been struck by then, or her distance from the house was different, putting it out of focus.

ceebee23
04-01-2017, 05:59 AM
One film that the Technicolor really bounces out at you is The Adventures of Robin Hood .... photography by Tony Gaudio and Sol Polito ..an early film stock to Oz (it was slower apparently).

Lots of exteriors.

It looks gorgeous on the cinema screen .... am sure it would look good on a CT100 or similar and bring a real range of Natalie's handiwork to the screen!

etype2
04-01-2017, 02:21 PM
The Robin Hood movie is listed frequently as one of the best Technicolor films to view.

Technicolor founders Herbert T. Kalmus and Natalie Kalmus considered The Red Shoes the best example of Three-Strip Technicolor. During the filming, Natalie often complained that Jack Cardiff wasn't following the rules laid down for Technicolor films and demanded that they re-shoot various scenes. However, Michael Powell always backed up Cardiff and they got the film they wanted.

I'm sure this was the psychedelic dark and deep colors scene at the end of the 15 minute ballet of the red shoes.

etype2
04-01-2017, 02:37 PM
A little know fact to me was in 1950 Natalie Kalmus licensed her name for a line of designer television cabinets made by a California manufacturer.

https://visions4netjournal.files.wordpress.com/2016/12/img_4554.jpg

https://visions4netjournal.files.wordpress.com/2016/12/img_4553.jpg

Edit: A friend sent his restoration photos of a Kalmus set. I have many more.

https://visions4netjournal.files.wordpress.com/2016/12/img_4555.jpg

https://visions4netjournal.files.wordpress.com/2016/12/img_4556.jpg

etype2
04-11-2017, 03:46 AM
As mentioned previously in this thread, our goal is to create a tribute video film for Ed Reitan outlining his career and specifically, his involvement in the restoration of the NBC color special, "An Evening With Fred Astaire".

We were lucky to win Ed's RCA CTC-7 Worthington at the 2015 ETF auction. The Worthington was released in the same year as the television special, 1958.

A generous doner friend sent me a copy of the television special recently, so we are going to undertake full restoration of the Worthington next month. The servo motors within the main chassis are frozen and none of the controls respond. The image had a few minor issues as well.

In the meantime, we created a "sneak preview" to view, showing portions of the video on my 21CT55, but our goal is to have it playing on Ed's Worthington. If you watch the video, check the 1080P video setting for best quality.

https://youtu.be/VmgmbtkvdKo

https://visions4netjournal.files.wordpress.com/2016/12/img_4709.jpg

old_tv_nut
04-14-2017, 12:36 AM
I just received "The Red Shoes" and the color is very nice. I had forgotten how many exterior scenes there are, and the Monte Carlo shots are nice. I caught one flub - as Moira Shearer is approaching a fancy building for a meeting, they are obviously following her with powerful spotlights and or reflectors to light her back, which is toward the camera but in shadow. At the very beginning of the shot, you see one of the spots whip across the courtyard in front of her, getting into position.

The set comes with bonus material including Martin Scorsese showing and commenting on the restoration process; he breaks it down into separate illustrations for the processes of removing mold spots, correcting misregistration, and correcting color breathing. Nothing short of amazing.

Edit: many of the shots other than daytime exteriors are rather low-key, which is not an easy thing to reproduce on a vintage color set with a dim picture and reflective tube face. To add to the fog, the CTC-5, like most vintage sets, has less than full DC coupling. I found it advantageous to turn off room lights except for the "TV light" I have that lights the wall behind the set, and turn down the brightness control a little. This made the exterior shots a little too dark, but you have to compromise or some of the interiors look foggy.

etype2
04-14-2017, 04:06 AM
I just received "The Red Shoes" and the color is very nice. I had forgotten how many exterior scenes there are, and the Monte Carlo shots are nice. I caught one flub - as Moira Shearer is approaching a fancy building for a meeting, they are obviously following her with powerful spotlights and or reflectors to light her back, which is toward the camera but in shadow. At the very beginning of the shot, you see one of the spots whip across the courtyard in front of her, getting into position.

The set comes with bonus material including Martin Scorsese showing and commenting on the restoration process; he breaks it down into separate illustrations for the processes of removing mold spots, correcting misregistration, and correcting color breathing. Nothing short of amazing.

Edit: many of the shots other than daytime exteriors are rather low-key, which is not an easy thing to reproduce on a vintage color set with a dim picture and reflective tube face. To add to the fog, the CTC-5, like most vintage sets, has less than full DC coupling. I found it advantageous to turn off room lights except for the "TV light" I have that lights the wall behind the set, and turn down the brightness control a little. This made the exterior shots a little too dark, but you have to compromise or some of the interiors look foggy.

That scene as she prepares to ascend the stairs was very noticeable and seems to be an obvious error that should have been caught. Also wonder why all the weeds were left to grow on the stone steps.

If you have a moderm television with a good color decoder and adjusted reasonably well, you owe it yourself to see the nuisances that the old roundie may not capture.

For anyone interested, we posted the entire ballet scene as reproduced by the RCA 21CT55 here at this link. Click on the 1080P setting for best quality.
https://m.youtube.com/watch?v=0zfc_EmieM0&feature=youtu.be

Edit: From IMDb, "On her first day of shooting, Moira Shearer got badly sunburned and developed a blister on her back. Later in the production she also wrenched her neck quite badly when called to leap from a window, and received a scratch that turned into an abscess. Shearer would often find herself being suspended in a harness for up to eight hours while being buffeted by wind machines."

Possibly they rushed the scene because of Shearer's complaining. It was her first film and she was nervous. I would be p****d if suspended in a harness for two minutes, oh the pain if you know what I mean.

old_tv_nut
04-14-2017, 11:33 AM
I also got the Blu-ray version for viewing on the big screen, have only had time to check a scene or two, but intend to watch the whole thing soon with all the detail the restored version can reveal.

etype2
05-22-2017, 10:06 PM
Well, we have declared the restoration of the RCA 21CT55 complete, until something breaks. :-) We fixed a centering problem, adjusted the focus and screezed out a bit more green. (Our latest screenshots of Oz confirm this)

We have prepared a 44 minute restoration documentary with screenshots and nine video clips.

https://visions4netjournal.files.wordpress.com/2016/12/img_5907.jpg



Edit: Discovered the embarrassing typo at the end in the credits. Will fix. Also fixed sound issues and added more information. Added diversity in the sound tracks which are royalty free. Can't upload the edited movie until next Monday. 5 GB a week limitation. Vimeo is higher quality, will display HD with no user interactions and displayed in full frame format.

Second edit: https://vimeo.com/219450643

Fixed the sound problem, added content.

etype2
11-08-2017, 03:01 AM
Update:

We were doing a video of the 21CT55 and it was running continuously for about 4 hours. We left the set running alone for no longer then three minutes and after returning, found the horizontal collapsed about one third of the screen, badly converged color, and out of focus. No unusual sounds or odors present. WHAT THE HECK HAPPENED! After much testing, we thought the flyback failed. The set was only producing 10KV. More testing with the HV probe and we pulled the regulator tube and found the HV was at its full 20KV. That led us to suspect a resistor in the HV regulator circuit. We tested it and fond it “open”. The suspect resistor was “buried” under the damper tube. This was done at my home and with lack of proper test equipment, off the chassis went once again to Mike’s test bench/shop.

From Mike:

Greetings. I installed the new resistor into the HV. regulator circuit and jigged it up tonight. I now have good control of the High Voltage with the adjustment. It regulates between 18 KV and 21 KV as it should. The raster is full, the focus is good and the convergence looks reasonable for being on the jig. You are a lucky man! It appears that the flyback transformer is OK. No photos tonight, it got too late but I will be taking a careful look at the Chroma circuits within the next couple of days to make sure that I have not missed anything, mainly looking at the complaint of lack of Green. Anything is possible at this point since this chassis seems to be full of “surprises” with its early color television circuitry.

Regards, Mike

Greetings. I have done more testing tonight in an effort to identify any issues with the chroma circuitry and paying special attention to the green. All voltages and waveforms looked acceptable. After the testing, the “technician” in me decided to do some “empirical” adjusting of some of the transformers in the chroma circuits. When doing these things, one must be VERY careful to go slowly unless “he” wants to start all over again with the procedures to get things aligned. When I got to L44 ( the Quadrature Transformer), I adjusted the slug out about 1/16th of a turn CCW and the green got stronger on the right side of the raster. All I can say, is, maybe the trip on the road caused the slug to settle a little inside the coil form. This adjustment made no difference in the voltages anywhere but it did improve the green “strength”. All I can say is, “whatever works” and I will not argue with success. This should, I hope, make in improvement in the green response even though the CRT is a bit tired. I have included photos of the resistor I found in the High Voltage Regulator circuit which was causing the reduced high voltage condition and hence the shrunk raster, out of focus and poor convergence symptoms. The High Voltage was reduced to 10 KV with this failure. It now adjusts nicely from 18 KV to 21 KV as it should. The resistor was an original (made by International Rectifier) special film type, 3.4 Megohm 3 watt. I replaced it with QTY 2 (in series) OHMITE 2.2 Megohm 2 Watt film type which now makes the new resistor a 4 watt unit which is a 25% upgrade for power dissipation. I will be cycling this set for a few days. Please find photos of the resistors and color bars. Please ignore purity issues.

Regards, Mike

Author:

All I can say is the failure was a blessing in disguise. After re-setting the grey scale and doing a complete new setup, the green output is strong now and all the other colors “fell into place” as they should and now look very accurate. It looks like a totally different CRT was installed. Great work Mike and indeed we are very lucky it was only a resistor causing the HV problem. The failure gave you an opportunity to revisit and take a “second look” at the chroma circuits and adjust that slug.

After we improved the color performance of the 1954/55 RCA 21CT55, we wanted to test it against the 1958 RCA CTC-7 Worthington. The 21CT55 uses a 21AXP22 CRT, testing a “weak” Good on emissions and the CTC-7 uses a rebuilt 21CYP22A CRT, testing a “strong” Good. The 21CT55 uses superior “R-Y-Q” demodulation. The following test images are an effort to visualize the differences in image and color quality between a 1954/55 RCA 21CT55 and the 1958 RCA CTC-7 Worthington. RCA 21CT55 images appear on the left series of photos. Tap any image to open the image carousel, then tap the full resolution image tab. All exposures and focus were set at the center of the CRT image automatically by an iPad Pro 2 10.5. This is not a scientifically controlled test, only an approximation attempt with a non-pro camera. Please excuse the reflections.

Go to this link and scroll to bottom of the page. There, you can open the image carousel to view full resolution photo comparisons of each image.

https://visions4netjournal.com/vintage-rca-color-tv-page-two-2/

https://visions4netjournal.com/wp-content/uploads/2017/11/79E74D12-8E62-4002-A355-5639E1872ED8.jpeg

https://visions4netjournal.com/wp-content/uploads/2017/11/5AEBDC6C-2F78-4A1C-AC4A-C25089DFC981.jpeg

https://visions4netjournal.com/wp-content/uploads/2017/11/F9D242A8-8244-4937-AEE2-00AADE318371.jpeg

CONCLUSIONS?
The first and obvious difference is the overscan of the CTC-7. The color temperatures are close in most of the photos comparisons. Where there are large differences, I believe it to be the fault of the camera. The camera seems to “shift” color temperature on its own. (Time to invest in a better dedicated camera) For instance, look at the fifth and sixth photo comparisons. You will also notice an annoying swath of pale yellow which is causing color variations or discolorations in the photos. This is caused by the camera and not visible when viewing directly. Also, these photos do not do justice to the actual images produced by these televisions. Overall the 21CT55 appears to be adjusted slightly “cooler” and the CTC-7 is brighter. The red gun of the 21CT55 is the weakest of the three.

Wondering why the CTC-7 has so much overscan and whether the overscan can be reduced to match the 21CT55?

benman94
11-08-2017, 10:41 AM
The CTC-2B still isn't set up correctly. RCA specified an ultor voltage of 25 kV. Get your HV up and the picture should be brighter yet, even with a weak tube. 20 kV is barely acceptable for a 21AXP22.

Better yet would be to track down a better 21AXP22 and get the HV up, but that isn't going to be easy (or cheap).

As it stands right now, the CTC-7 looks to my eyes to have the superior image, even with the overscan.

etype2
11-09-2017, 01:45 AM
We did measure 21KV. Still short of 25KV. Would like to find a spare flyback, but that isn’t likely either.

benman94
11-09-2017, 08:18 AM
Keep digging. A 21-CT-55 flyback can kick out 30+ kV unregulated. Is your fly damaged?

If it is, I'm going to suggest something that is anathema to most around here: use a solid state HV supply. The set is not working correctly in the first place, so originality doesn't count for jack at the moment.

A solid state HV supply would get the set performing closer to how it was designed.

Best of luck in either case.

Celt
11-09-2017, 09:51 AM
Speaking of Lizard From Oz...

http://videokarma.org/attachment.php?attachmentid=195875&stc=1&d=1510239036

etype2
11-09-2017, 10:57 AM
Keep digging. A 21-CT-55 flyback can kick out 30+ kV unregulated. Is your fly damaged?

If it is, I'm going to suggest something that is anathema to most around here: use a solid state HV supply. The set is not working correctly in the first place, so originality doesn't count for jack at the moment.

A solid state HV supply would get the set performing closer to how it was designed.

Best of luck in either case.

We thought the fly was toast initially when the failure happened. We measured only 10KV. The thought was the fly was still good otherwise it would measure zero. It turned out to be an open resistor. I’d just like to have a good spare. Best chance for that is finding another 21CT55.

etype2
11-09-2017, 10:59 AM
Speaking of Lizard From Oz...

http://videokarma.org/attachment.php?attachmentid=195875&stc=1&d=1510239036

I think TCM broadcasts Oz annually.

benman94
11-09-2017, 11:27 AM
We thought the fly was toast initially when the failure happened. We measured only 10KV. The thought was the fly was still good otherwise it would measure zero. It turned out to be an open resistor. I’d just like to have a good spare. Best chance for that is finding another 21CT55.

What I'm driving at here is that 21 kV is not at all normal for a 21-CT-55, and is not good enough. The Hoffman I sold to Nick would uses the same exact HV section and would crank out 30 kV or more with the shunt pulled. Something has to be loading down the HV, my guess is that there's still some issue with the 6BD4A or the associated circuitry. Don't throw in the towel on the HV issue, and DO NOT run the set until it is properly fixed. Droopy HV could also be failing HV caps which WILL take out your flyback.

Electronic M
11-09-2017, 11:48 AM
Speaking of Lizard From Oz...

http://videokarma.org/attachment.php?attachmentid=195875&stc=1&d=1510239036

:lmao: All the makings of a timeless children's classic! :D

miniman82
11-09-2017, 09:42 PM
What is your HV reading with the HV control at max? It’s not uncommon to have to play with the value of the resistors around the HV pot, since any drift there will cause the grid of the shunt tube to not be where it’s supposed to be which drags down the anode.

etype2
11-09-2017, 09:59 PM
What is your HV reading with the HV control at max? It’s not uncommon to have to play with the value of the resistors around the HV pot, since any drift there will cause the grid of the shunt tube to not be where it’s supposed to be which drags down the anode.


We replaced a resistor in the HV regulation circuit which was found open. This caused the HV to drop to 10KV and messed up the picture badly. The resistor was an original (made by International Rectifier) special film type, 3.4 Megohm 3 watt. We replaced it with QTY 2 (in series) OHMITE 2.2 Megohm 2 Watt film type which now makes the new resistor a 4 watt unit which is a 25% upgrade for power dissipation.

miniman82
11-09-2017, 10:59 PM
That could be your problem, original calls for 3.4 meg and you installed 4.4 meg. Compare the grid voltages on the 6BK4 with what the schematic shows, my guess is it’s a tad high. (Measurement should be taken with brightness at minimum)

Here’s how the regulator works, in case you were unaware:

Plate receives anode voltage, cathode is returned to B+, grid is tied to a boost source usually. If boost rises anode voltage must also have risen, since they are in the same circuit. This higher boost voltage causes the regulator to draw more current, since the grid got pushed closer to the cathode (the tube is normally biased off, with the cathode over the grid). With the regulator drawing current the anode voltage will get dragged down taking boost along with it, in turn taking the grid of the regulator lower and turning it more off.

In this way the regulator tube places a constant load on the anode, but if it’s biased a little too hot to start off with the result will be consistently low HV because the regulator is dragging it down.

The correct HV setting for this chassis is 25kv, I suggest you take Ben’s advice and figure out why it’s low before the flyback protests too much. You also need to know what the horizontal output tube is drawing for current, if it goes much higher than about 215ma, you’re in the danger zone.

We already witnessed another member destroy an irreplaceable CTC-2B flyback by not heeding sound advice, please don’t be the second.

benman94
11-09-2017, 11:09 PM
I would like to point out that the Sams Photofact doesn't even show a 3.4 meg resistor in the regulator circuit. I'll pull my factory service literature tomorrow to look for running changes, but I'm not anticipating anything like that. Your set needs to be looked at by a competent tech, period.

miniman82
11-09-2017, 11:37 PM
I would like to point out that the Sams Photofact doesn't even show a 3.4 meg resistor in the regulator circuit. I'll pull my factory service literature tomorrow to look for running changes, but I'm not anticipating anything like that. Your set needs to be looked at by a competent tech, period.

I don’t see one in Sams or the white book (service clinic) covering this set, but interestingly Sams list the regulator as a 6BD4 same as the CT-100. White book calls it a 6BK4, wonder if this chassis has the same wiring goof the CT-100 has under the regulator socket?

etype2
11-10-2017, 12:55 AM
That could be your problem, original calls for 3.4 meg and you installed 4.4 meg. Compare the grid voltages on the 6BK4 with what the schematic shows, my guess is it’s a tad high. (Measurement should be taken with brightness at minimum)

Here’s how the regulator works, in case you were unaware:

Plate receives anode voltage, cathode is returned to B+, grid is tied to a boost source usually. If boost rises anode voltage must also have risen, since they are in the same circuit. This higher boost voltage causes the regulator to draw more current, since the grid got pushed closer to the cathode (the tube is normally biased off, with the cathode over the grid). With the regulator drawing current the anode voltage will get dragged down taking boost along with it, in turn taking the grid of the regulator lower and turning it more off.

In this way the regulator tube places a constant load on the anode, but if it’s biased a little too hot to start off with the result will be consistently low HV because the regulator is dragging it down.

The correct HV setting for this chassis is 25kv, I suggest you take Ben’s advice and figure out why it’s low before the flyback protests too much. You also need to know what the horizontal output tube is drawing for current, if it goes much higher than about 215ma, you’re in the danger zone.

We already witnessed another member destroy an irreplaceable CTC-2B flyback by not heeding sound advice, please don’t be the second.

Thank you very much for this information.

etype2
11-10-2017, 12:57 AM
I don’t see one in Sams or the white book (service clinic) covering this set, but interestingly Sams list the regulator as a 6BD4 same as the CT-100. White book calls it a 6BK4, wonder if this chassis has the same wiring goof the CT-100 has under the regulator socket?

Can you tell me more about “wonder if this chassis has the same wiring goof the CT-100 has under the regulator socket?[/QUOTE]“ to bring me up to speed.

etype2
11-10-2017, 01:08 AM
I mentioned your recent comments to my friend Mike who has done 99% of the work on both the 21CT55 and the CTC-7. I myself can only do the basics. Mikes comments:

“The absolute high voltage rating for the 21AXP22 is 27,500 Volts and the design values are between 20,000 and 25,000 volts. I set yours for 21KV which produced good focus. And the Grid 3 volts (focus) volts will rise linearly with the high voltage since that voltage is derived from the tripler set of 3A2 tubes. And THAT grid has a maximum rating of 6600 volts which you do not want to exceed. And YES, the set will produce 30KV with the regulator pulled. I tested it that way when I was verifying the regulator functions. It does NOT mean that you run the CRT at that voltage!!! The regulator tube is, by definition, a SHUNT REGULATOR circuit. What that means is that it is designed to SHUNT the UNUSED high voltage to GROUND as a function of its design. There are no issues with capacitors as far as I could tell here. Are you having problems with the picture? You can look up the PDF file for the 21AXP22 if you want to learn more about its design values. There is a FUSE in the circuit to protect the flyback from overload in the event that it occurs.”

I will ask Mike to join in on the conversation as he is a VK member. He just had long needed surgery, so it might not be to soon.

Edit: I checked both the RCA and Sylvania data sheets and confirm the voltage figures cited by Mike. However, RCA states “25KV Max.”

benman94
11-10-2017, 09:10 PM
This discussion is going to devolve even further if left open. I'm preemptively shutting this down for the time being. If another moderator sees reason to open back up have at it.

At this point, I think everybody has said their piece about the risks, real or "perceived", to Mr. Wozniak's flyback. There is little, if anything, to add to the discussion.

Eric H
11-11-2017, 01:17 AM
I have deleted everything from this last day in an attempt to get this thread back on track.

If it can go forward in a more civil manner it will stay open.

etype2
11-12-2017, 10:28 PM
https://visions4netjournal.com/wp-content/uploads/2017/11/26913064-692C-4F8E-B866-E6578A5787B9.jpeg

Recap of the restoration of a RCA 21CT55 without having to read the entire 10 pages of this thread.

The set was fully restored last January, 2017. It took two years and we thank all the VK members who helped and especially Mike Doyle, also a VK member. In July we were doing a video of the 21CT55 and it was running continuously for about 4 hours. We were done and ready to shut the set down. I left the set running alone for no longer then three minutes for a bathroom break and after returning, found the horizontal collapsed about one third of the screen, badly converged color, and out of focus. No unusual sounds or odors present. I know, first rule, never leave a vintage set unattended. WHAT THE HECK HAPPENED! WHAT LUCK!

After much testing, we thought the flyback failed. The set was only producing 10KV. That was a good sign. More testing with the HV probe and we pulled the regulator tube and found the HV measured 20KV. I can’t remember what the previous voltage was. That led us to suspect a resistor in the HV regulator circuit. We tested it and found it “open”. The suspect resistor was “buried” under the damper tube. This was done at my home and with lack of proper equipment and expertise, off the chassis went once again to Mike’s test bench/shop.

Mike found the open resistor “buried” under the damper tube. He then addressed the color problem I complained about, weak green output. I blamed it on the somewhat tired 21AXP22. It still test “good” but on the low side at cutoff. It tuned out that a simple 1/16 turn CCW of a slug in the L44 Quadrature Transformer made all the difference. The green returned strong and looked good on Mike’s jigged CRT. The resistor was an original (made by International Rectifier) special film type, 3.4 Megohm 3 watt. Mike replaced it with QTY 2 (in series) OHMITE 2.2 Megohm 2 Watt film type which now makes the new resistor a 4 watt unit which is a 25% upgrade for power dissipation.

Mike let the chassis “cook” (exaggeration) several hours a day for a week. During this time, he monitors the chassis for any anomalies, checks voltages, etc. The HV is 30 KV with the regulator tube pulled. All looked good and the chassis was delivered back to me. We reset the gray scale and did a full setup. We could not get the convergence perfect. Settled for good convergence in the center, top, bottom and left side. The bottom convergence is just as important as the center. Broadcasts usually show text at the bottom. The 21AXP22 looks like a new CRT now. We are happy!

Operational observations: The set comes up with good convergence and seems to reach full brightness in 30 seconds. The image enlarges to a point that after about 25 minutes the annoying Macrovision streaks on the “Gentlemen Prefer Blondes” DVD disappear at the top of the screen.

The cabinet is in good shape but we will refinish the top which has blistering of the old varnish. We still have to polish the brass trim around the CRT safety screen.

Here, a few more screenshots from the 1953 Technicolor movie, “Gentlemen Prefer Blondes”. I’m very pleased with the results.

This link will open an image carousel and full resolution images of the thumbnails can be viewed.

https://visions4netjournal.com/vintage-rca-color-tv-page-two-2/#jp-carousel-3964

This link will show images from OZ and THE RED SHOES.

https://visions4netjournal.com/vintage-rca-color-tv-page-two-2/#jp-carousel-3856

If anyone has a copy of the “Service Clinic” booklet for the 21CT55, I’d appreciate it. I checked the ETF and internet. Nothing found. I would like to address the concerns expressed about the HV by several VK members. The resistor failure concerns me but then again, it’s a 62 year old set. Things fail. We can’t replace every single part.

Thanks.

benman94
11-13-2017, 11:06 AM
Can you tell me more about “wonder if this chassis has the same wiring goof the CT-100 has under the regulator socket?“ to bring me up to speed.

See this link:

http://www.earlytelevision.org/Deksnis/CAUTION_6BD4-6BK4.htm

In short, pin 8 on the 6BD4 socket in the CT-100 is used as a tie point. It is not used as a tie point in the 21-CT-55, so you can use any 6BD4A, 6BK4, or 6EL4A you choose.

benman94
11-13-2017, 11:24 AM
Regarding the correct 25 kV ultor voltage, see this quote from the RCA booklet entitled "Technical Features of the RCA Victor Model 21-CT-55 Color Television Receiver":

The RCA Victor Model 21-CT-55 color television receiver is a direct-view console which reproduces high-quality television pictures in full color from a standard color television signal, and automatically, with no adjustment or attachments, high-definition black-and-white television pictures from a standard black-and-white television signal.

The picture displayed on the screen of a 21-inch tricolor kinescope, the 21AXP22, has an area of approximately 255 square inches (2 1/2 times the CT-100). The 21AXP22 employs electrostatic focusing and electromagnetic convergence. Ultor voltage is 25,000 volts. In conjunction with the 21-inch tricolor kinescope, the convergence and purity arrangements provide ease of adjustment, and increased accuracy and stability of color registration.

One of the customer convenience features in this receiver is that convergence and focus are no longer customer adjustments from the side of the cabinet but are internal and are preset by the service technician.

Additional features include: a removable top panel to facilitate servicing and adjustment, and the location of most of the functional controls at the receiver front. These control are located under the tilt-down control cover or behind the removable wood panel directly below the control cover. Dual loudspeakers are provided for sound reproduction.

(Emphasis added by yours truly.)

I'm still failing to see what is ambiguous about the RCA specified ultor voltage, but to be honest I really don't care any more... I tried to help, I only hope you correct the issue before your flyback goes up in smoke.

Anyway, here is the factory service data you asked for "1954 No. T13", published November of 1954: http://docdro.id/HBjbl9P

You'll note that the only 3.3 MOhm resistor is in the grid circuit of the triode section of the 6AN8 that serves as the R-Y amp and phase splitter. I'm not sure what resistor Mike replaced in the 6BD4A circuit with two 2.2 MOhm resistors in series. Apparently he's smarter than RCA's own engineers. I guess we should all defer to some random guy with a soldering iron instead of the factory service literature...

Electronic M
11-13-2017, 01:15 PM
Thanks for posting the RCA info. It will be nice to be able to reference in addition to the sam's folder.

etype2
11-13-2017, 07:53 PM
Thanks for posting the link and the “T13”. There was a reference earlier to the “service clinic” or “white book” booklet. Do you have that as well?

I’ve have the service clinic for the CTC-7. I have the Sams for both sets and the “Field service guide” manuel.

benman94
11-14-2017, 04:54 PM
Thanks for posting the link and the “T13”. There was a reference earlier to the “service clinic” or “white book” booklet. Do you have that as well?

I’ve have the service clinic for the CTC-7. I have the Sams for both sets and the “Field service guide” manuel.

"Technical Features of the RCA Victor Model 21-CT-55 Color Television Receiver" is the service clinic. It doesn't contain any information that the official service data, the "T13" booklet, doesn't already contain.

To my knowledge, these are the only two official service documents regarding the CTC-2B. There may be others that I'm unaware of, but I doubt it.

I believe Nick has a copy of the Service Clinic, but given how dismissive you were of his attempt to help, he probably won't bother to post it. I wouldn't blame him either...

miniman82
11-14-2017, 06:21 PM
I have the Sams for both sets and the “Field service guide” manuel.

Uh huh, and what does Sams say to set the anode voltage to on page 14???

benman94
11-14-2017, 06:28 PM
Uh huh, and what does Sams say to set the anode voltage to on page 14???

I'm going to hazard a wild ass guess... is it the same value found on page 17 of the factory service manual I uploaded? :stupid:

miniman82
11-14-2017, 06:37 PM
If I told you I’d have to kill you. :)

Findm-Keepm
11-15-2017, 11:34 AM
Regarding the correct 25 kV ultor voltage, see this quote from the RCA booklet entitled "Technical Features of the RCA Victor Model 21-CT-55 Color Television Receiver":



(Emphasis added by yours truly.)

I'm still failing to see what is ambiguous about the RCA specified ultor voltage, but to be honest I really don't care any more... I tried to help, I only hope you correct the issue before your flyback goes up in smoke.

Anyway, here is the factory service data you asked for "1954 No. T13", published November of 1954: http://docdro.id/HBjbl9P

You'll note that the only 3.3 MOhm resistor is in the grid circuit of the triode section of the 6AN8 that serves as the R-Y amp and phase splitter. I'm not sure what resistor Mike replaced in the 6BD4A circuit with two 2.2 MOhm resistors in series. Apparently he's smarter than RCA's own engineers. I guess we should all defer to some random guy with a soldering iron instead of the factory service literature...

From 1954......hmm... do you have the 13 Goldenrods (service Bulletins) issued against the 21CT55? (I don't either...) The last one was issued in 1972....and probably a parts stoppage report. Many of these Goldenrods were safety issues - without them, the original service literature is a snapshot in time.

By 1978 (when we got our first RCA service library, from RCA, 28 binders, TV only...), some 600+ Goldenrods had been issued by RCA for televisions. Some were minor part number changes, but in the case of ALL early color (CTC17 and earlier), RCA issued Goldenrods to limit the 2nd anode voltage in all sets to a value that reflected the amount of shielding around the regulator tube.

I'm not Chicken Little, crying about the X-rays - I'm merely pointing out that the original service lit has been revised many, many times and some original statements and values rescinded.

RCAman, a frequent poster, may still have an RCA library with the Goldenrods. Ours went the way of another shop when we closed up in 2008. They tossed all the tube stuff - I rescued what they still had - CTC72 and up, unfortunately.

Nick/Miniman82 - same as any NAVAIR pub change - remove the old stuff and put in the new, up-to-date stuff. Old values/procedures and part numbers no longer apply...

miniman82
11-15-2017, 12:08 PM
Gonna have to disagree with the pub analogy, in this case I know better than to put unnecessary electrical strain on 60 year old parts. Besides, we’ve both been around long enough to see a pub or two with bullsh!t procedures in it.

Electronic M
11-15-2017, 12:36 PM
These sets were in service for around a decade when the X-Ray alarmists got started...A pre X-ray scare HV reduction I'd buy as merited, but any X-ray scare reductions I'd regard as superfluous and 'not running the set as it would have been during most of it's intended service life'. I rather see a CTC-2/CTC-2B doing what it would have done in the 1954-1963 time frame, than what it would do in 1967-1975.

benman94
11-15-2017, 12:53 PM
These sets were in service for around a decade when the X-Ray alarmists got started...A pre X-ray scare HV reduction I'd buy as merited, but any X-ray scare reductions I'd regard as superfluous and 'not running the set as it would have been during most of it's intended service life'. I rather see a CTC-2/CTC-2B doing what it would have done in the 1954-1963 time frame, than what it would do in 1967-1975.

Agreed. As mentioned previously, the X-ray scare was completely unwarranted. Stick a 6EL4A in the set if you're that worried about it and call it a day. The X-rays are soft and the dose from a 21AXP22 face at 25 kV, or a shunt reg at 25 kV, is going to be negligible. I work with Coolidge tubes all day long. Trust me, if there were any real risks from a CRT I'd be the first to chicken little... You're more likely to be electrocuted by your CTC-2B.

I still have yet to see a logical reason to run this set at less than 25 kV, but plenty to run it at spec...

But if you don't believe me, defer instead to John Yurkon, a physicist as well, who has done actual testing on CRTs:

http://www.videokarma.org/showthread.php?t=112954

etype2
11-15-2017, 02:32 PM
From 1954......hmm... do you have the 13 Goldenrods (service Bulletins) issued against the 21CT55? (I don't either...) The last one was issued in 1972....and probably a parts stoppage report. Many of these Goldenrods were safety issues - without them, the original service literature is a snapshot in time.

By 1978 (when we got our first RCA service library, from RCA, 28 binders, TV only...), some 600+ Goldenrods had been issued by RCA for televisions. Some were minor part number changes, but in the case of ALL early color (CTC17 and earlier), RCA issued Goldenrods to limit the 2nd anode voltage in all sets to a value that reflected the amount of shielding around the regulator tube.

I'm not Chicken Little, crying about the X-rays - I'm merely pointing out that the original service lit has been revised many, many times and some original statements and values rescinded.

RCAman, a frequent poster, may still have an RCA library with the Goldenrods. Ours went the way of another shop when we closed up in 2008. They tossed all the tube stuff - I rescued what they still had - CTC72 and up, unfortunately.

Nick/Miniman82 - same as any NAVAIR pub change - remove the old stuff and put in the new, up-to-date stuff. Old values/procedures and part numbers no longer apply...

Interesting. So RCA issued “Adendums” / Goldenrods to update service data. I wonder if Mike has those for the 21CT55?

etype2
11-15-2017, 02:46 PM
https://visions4netjournal.com/wp-content/uploads/2017/11/03720F4D-F5D1-4EA3-80EA-689F68A8D6B0.jpeg

I see that on pages 6 and 17 of the T13, RCA calls for setting the ultra voltage at 25KV.

What I’m trying to understand is how does this relates.

In the RCA data sheet for the 21AXP22A,

RCA states: max 25KV ultor voltage.

RCA states: equipment design range with any ultra voltage 20 to 25KV.

Look I’m not a tech, my 41 year career after the Navy was real estate law. Just trying to understand.

I remember Mike telling me that the Sams procedure for alignment was incorrect, don’t remember the specifics. This would not be the first time service manual’s are incorrect.

benman94
11-15-2017, 03:16 PM
Marshall,

Look again at the arrow in the datasheet you posted. The words "Design Center" are key here. The design center system of maximum ratings means it is completely safe to run the maximum allowed value. Design center means you can actually exceed the maximum value listed by about 10 to 20 percent, and provides a built in safety margin for parts value variation, manufacturing tolerances in parts, etc

benman94
11-15-2017, 03:24 PM
Look at this datasheet for the 15HP22: https://frank.pocnet.net/sheets/084/1/15HP22.pdf

CBS ran them at 20 kV ultor voltage.

Look at this datasheet for the 15GP22:
https://frank.pocnet.net/sheets/093/1/15GP22.pdf

Every manufacturer ran them at 20 kV (19.5 kV in the case of RCA, which is a negligible difference).

Look at this datasheet for the 10FP4 CRT. Most 10 inch sets ran them right at 10 kV or damn close to it.

https://frank.pocnet.net/sheets/201/1/10FP4.pdf

Do you see the pattern. Running at design center maximum is perfectly fine, and in the case of a CRT, often desirable.

Electronic M
11-15-2017, 04:00 PM
Your last two posts took the words out of my mouth before I could write them, Ben.


To add to your running at design center max being desirable. Most manufactures tried to do that for a couple of reasons: Brighter picture, and CRT life. The cathode material of a CRT has a somewhat finite number of electrons it can emit before the emissive material is depleted. The higher the HV the less gun current is needed for a given brightness setting, the less current the fewer electrons needed from the cathode for the same result, the fewer electrons used for desired result the longer the CRT life.

Also I'm not trying to knock your tech, but I remember you quoted your tech as saying that the HV regulator "shunts the excessive voltage" which conceptually is wrong. The regulator shunts current not voltage from the HV line to ground. You see every power supply has to obey the laws of Thévenin...That is there is no ideal voltage source. Every voltage source has an internal resistance, and that internal resistance forms a voltage divider with the load (CRT+HV reg tube). In the case of varying loads (such as a CRT) the output voltage varies as a function of load current drawn through internal supply Thévenin resistance. The HV reg is configured to attempt to increase it's relative current draw instep with decreases in CRT current draw (caused by video content), and decrease when the CRT increases. If the current through a Thévenin resistance is held constant (which is what the HV reg tube is meant to do) then the output voltage of the supply is also held constant.

There is also an average current to the HV reg that is adjusted by the HV level pot....The lower you set the HV level the higher the constant/average current (sum of CRT and HV reg tube) is on the HV winding of the flyback. The Thévenin resistance lives in the fly windings in the case of a TV like this, and thus the higher the HV current you put through it the higher the heat and strain on the flyback.

Many RCA flybacks were being pushed hard by design, adding to it does not strike me as desirable.

benman94
11-15-2017, 04:32 PM
Your last two posts took the words out of my mouth before I could write them, Ben.


To add to your running at design center max being desirable. Most manufactures tried to do that for a couple of reasons: Brighter picture, and CRT life. The cathode material of a CRT has a somewhat finite number of electrons it can emit before the emissive material is depleted. The higher the HV the less gun current is needed for a given brightness setting, the less current the fewer electrons needed from the cathode for the same result, the fewer electrons used for desired result the longer the CRT life.

Also I'm not trying to knock your tech, but I remember you quoted your tech as saying that the HV regulator "shunts the excessive voltage" which conceptually is wrong. The regulator shunts current not voltage from the HV line to ground. You see every power supply has to obey the laws of Thévenin...That is there is no ideal voltage source. Every voltage source has an internal resistance, and that internal resistance forms a voltage divider with the load (CRT+HV reg tube). In the case of varying loads (such as a CRT) the output voltage varies as a function of load current drawn through internal supply Thévenin resistance. The HV reg is configured to attempt to increase it's relative current draw instep with decreases in CRT current draw (caused by video content), and decrease when the CRT increases. If the current through a Thévenin resistance is held constant (which is what the HV reg tube is meant to do) then the output voltage of the supply is also held constant.

There is also an average current to the HV reg that is adjusted by the HV level pot....The lower you set the HV level the higher the constant/average current (sum of CRT and HV reg tube) is on the HV winding of the flyback. The Thévenin resistance lives in the fly windings in the case of a TV like this, and thus the higher the HV current you put through it the higher the heat and strain on the flyback.

Many RCA flybacks were being pushed hard by design, adding to it does not strike me as desirable.

I hadn't even considered the lower cathode current. That's a good point Tom. The major issue that RCA was driving at was inefficient phosphors coupled with the shadow mask design.

The primary issue is that the red phosphor was extremely inefficient. The underlying physical process of exciting a phosphor is more efficient with higher energy electrons, which in turn demands higher anode voltage.

Side bar: This is the reason that many Zenith Walton owners have resorted to connecting the B+ for the eye tube (the rare Zenith specific one, 6T5 maybe?) with 500+ volts from a solid state source hidden in the set. With a burned P1 Willemite phosphor, that 500+ volts can bring back sufficient brightness. The cathodes in these tubes are usually still quite strong.

Also keep in mind that the shadow mask blocks a vast majority of the electrons leaving the cathodes. They simply strike the shadow mask and return through the HV lead back to the chassis, never striking a phosphor and therefore never producing light. This is why the Lawrence Tube, the Apple tube, the Sony Chromatron and Trinitron, etc were explored.

RCA took a different approch. Modify the existing shadow mask design to a degree and develop newer brighter more efficient phosphors. This of course culminated with the rare earth types.

Another note about design center: one of the biggest variables in those days was the line voltage. It could range from 105 V to 120 V at the outlet. In most places this issue has been corrected, and the tolerance is nearer to 120 +/- 5% at the service drop to the house. This variability circa 1954 caused proportional shifts in filament voltage and B+.

If you're one of the unlucky folks that lives at the end of a rural circuit serviced by DTE or Consumers, the situation hasn't changed at all since 1954...

etype2
11-15-2017, 05:16 PM
Good information flowing ...

Just read a 1954 paper by RCA last night. This particular tubes shadow mask, 21AXP22 blocks 85% of the electrons. This same figure was presented to the IEEE in a paper entitled “THE PDF CHROMATRON-A SINGLE OR MULTI-GUN TRI-COLOR CATHODE-RAY TUBE by Robert Dressler from the PROCEEDINGS OF THE I.R.E. VOL.41, NO. 7, JULY, 1953”, priniple engineer at Chromatic Television Laboratories’s Inc., developers of the Chromatron tube. The slot mask was an effort by American manufactures to increase the electron flow to the phosphors.

Like I said previously, I’m taking everything said seriously. We will curtail running the 21AXP22 until I have a chance to sort all of this out with Mike. He is about to have a second surgery and don’t want to bother him.

Any comments about the latest screenshots after the slug was adjusted?

benman94
11-15-2017, 05:22 PM
Just read a 1954 paper by RCA last night. This particular tubes shadow mask, 21AXP22 blocks 85% of the electrons. This same figure was presented to the IEEE....

And this is exactly what I referred to in my last post. This is yet another reason why you run the jug at 25 kV...

As far as the screenshots go, I can tell, especially in comparison to the CTC-7, that the image is on the dim side. Otherwise they look alright.

etype2
11-17-2017, 02:00 AM
See the slideshow at the bottom of this link page.

https://visions4netjournal.com/vintage-rca-color-tv-page-two-2/