Restoring a RCA 21CT55

[old_tv_nut]

Look at the red wall in the upper left of this one and you can see the chroma dots in the red area quite plainly:
https://i2.wp.com/visions4netjournal...2B99BB373.jpeg

If you don't have a SMPTE color bar signal, you could still-frame this scene and tune the chroma subcarrier trap for minimum dots on the flat red area.

[etype2]

I’m certain I see what you’re referring to. I do have a SMPTE color bar signal. Okay, will put my eyes on it. Will try the adjustment both ways if necessary. In a few weeks after the adjustment, plan to post a few “Kiss Me Kate” screenshots.

[old_tv_nut]

When viewing them, they will be moving, not stationary as in the snapshots. It is important to view a large flat area of color. That's why color bars are best. Variable areas and edges generate sidebands that produce dots that cannot be nulled out by the trap. You will always see some dot crawl on edges. If you have an oscilloscope, you can look at the luminance amplifier output and null the "fuzz" caused by the subcarrier.

[etype2]

That is very helpful. Thank you. No scope. Those dots are in just about every shot. Would have never known. I thought what we are seeing as normal.

[etype2]

Just want to add: In the nightclub scenes, Marilyn’s dress is orange, not red.

[etype2]

I went looking looking for Kiss Me Kate, but the stores only had the BluRay version. I have an inexpensive DVD player hooked up to my modulator. I order a copy and will post the screenshots later.

Gone With The Wind on a 21CT55 with a 21AXP22 photographed May 6, 2018.



See this shot and 8 more in full resolution 6000X4000 at this link: https://visions4netjournal.com/2018/...-carousel-4923



It is impossible to see those dots that Wayne talked about on a moving live screen (with my 72 year old eyes).

[etype2]

No, this is not a HD shot. It’s Vivien Leigh as Scarlet O’Hara in the 1939 film, Gone With The Wind, photographed May 6, 2018 on a 63 year old television.

[etype2]

The original 6000X4000. https://i0.wp.com/visions4netjournal...47D.jpeg?ssl=1

[etype2]

Requested by member. Kiss Me Kate screenshots, 1953 on a RCA21CT55.



Original: https://visions4netjournal.com/wp-co...1C1835A34.jpeg



Full resolution: https://visions4netjournal.com/2018/...-carousel-5083

[old_tv_nut]

My only comment at this point is that the shadows in many shots look blue. What does a gray scale look like?

[etype2]

The grey scale is good at this time. It may be slightly cold. I think this has to do with the movies color balance itself.

If you look at Gone With the Wind, the shots look consistently warm.

[old_tv_nut]

Hmmm. When I look at the picture of Scarlett in the straw hat, I see warm highlights, but blue shadows (her hair). Before you ask - my monitor is properly calibrated.

There also is something strange in that the blue black level seems higher toward the bottom of the screen (it's less cut-off).

[old_tv_nut]

Just had a thought - the blue DC restorer may be weak. This would cause the blue background to drift the opposite of the dominant color and possibly vary over the height of the picture. You wouldn't see this on a grayscale pattern.

[etype2]

Originally Posted by old_tv_nut

Just had a thought - the blue DC restorer may be weak. This would cause the blue background to drift the opposite of the dominant color and possibly vary over the height of the picture. You wouldn't see this on a grayscale pattern.

We played with the background controls a lot. I don’t have professional test equipment, so I used the blue filter with the Video Esentials disk to calibrate. I know this is not the best way, at a disadvantage without proper tools.

[old_tv_nut]

Originally Posted by etype2

We played with the background controls a lot. I don’t have professional test equipment, so I used the blue filter with the Video Esentials disk to calibrate. I know this is not the best way, at a disadvantage without proper tools.

This technique should be fine if the DC restoration is good or bad, because the usual test patterns (gray scale or color bars) have constant average current in the three guns. But, on regular video, when a scene has a lot of one color in the highlights, the DC restorers have to work to counter the change in average currents between the guns; so when you have a face and yellow hat filling much of the screen, the tracking gets pushed towards blue if the DC restorers are weak. I think replacing that tube would be worth a try.