Restoring a RCA 21CT55

[old_tv_nut]

"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.

[benman94]

Originally Posted by old_tv_nut

"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]

Originally Posted by benman94

... "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]

Originally Posted by old_tv_nut

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.

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