Do "roundie" color sets make a better picture than later sets?

[rca2000]

I THINK what people are refering to is what is known as the "200 volt cap". It is in the bias supply to the CRT cathodes. Nearly always--it is a flyback-derived supply--on solid state sets. Even BW sets have this cap--including the 1M30T20--it is called the 120 volt supply--and derived from the flyabck.

It will be from a 2.2 UF to a possible 33UF, Usually 250 volts or more--but some late 70's to 90's sets tied that cap to the B+ supply --so it only sees the increase from the flyback on it.

Occasionally--this cap is on the CRT board--but usually on the chassis, and often near the flyback.

[dtvmcdonald]

I decided to look carefully again at the color rendition of my CT-100.
It was not as good as I remembered. I could adjust the hue control to get
mid-scale violets/magentas or yellows/oranges right, but not both.

I took the top off with the intent to tweek. But doing the critical
adjustments is impossible without pulling the chassis partly out. Too
little clearance with the CRT. So I said, just do a check on
all my normal test patterns from a USB key on the Blu-Ray and
leave it at that. Success! the problem was not the hue control!
It was "color" ... there is just zero way to set both hue and color
correctly without a proper static color bars pattern and the Digital
Video Essentials color filters or equivalent. Near perfect match
between big TV, computer monitor, and CT-100 on a slide show
(with color temperatures on LCDs set to match CT-100). Back
to OTA and still a great match.

Moral: don't complain about color rendition without setting color bars right.
Ideally you want 75% brightness 100% saturated bars. I have
special tests I made up (and posted) that allow you to use either blue
or red bars (or green ones if you have a proper dichroic filter better than
the plastic ones) but blue alone is OK if the room
is truly dark.

[zeno]

Let me clarify.
I was referring to tvcollectors 1981 Hitachi with a shading problem.
The problem is so common I will go over it for those with less experience.
This is an ALMOST ALWAYS tutorial.
All solid state sets use 200 V to run the 3 color outputs.
The 200V comes from
1) a secondary flyback winding ( most common)
2) OR not commonly off the primary & is stacked off the 130V.
there are 2 caps involved in this case.

Symptoms are any or all of the following.
To bright
Jail bars
Brighter on left than right
Retrace lines.
Streaking
Poor color
HV shut down ( from too much beam current)

How to find the cap.
Find the 3 color outputs, usually on the CRT board.
Each has a 1 or 2 watt resistor ( 18K + or - ) off the collectors.
The other ends join together, thats the 200V.
Follow the wire from that point back to the chassis.
You will find the cap at the cathode of a diode.
Sometimes there is a coil or low value resistor in series with
everything.
Of course if you cant find it post the model & chassis & one
of us will look it up.

BTW some sets cam in with another problem but just didnt
look right. It was this cap just starting to go. I always loved this
problem, a gravy job that put steaks on the table & beer in
the frig

73 Zeno

[etype2]

Here is a comparison. First photo is from Ed Reitan's CBS field sequential television. Correction: Photography from the screen of John Folsom's 1950 CBS Labs RX-43 CBS Color Receiver as seen on Ed Reitan's website.



Second photo is from a 70 inch 2012 Sharp Quatron LCD.

[etype2]

dtvmcdonald,

Would it be possible for you to post the identical screenshot of Dorothy as seen on your CT-100?

Added: ... Or anyone else that owns a CT-100. Would love to see a comparison screenshot of the identical frame of Dorothy on your CT-100.

[Electronic M]

Originally Posted by etype2

Here is a comparison. First photo is from Ed Reitan's CBS field sequential television. Correction: Photography from the screen of John Folsom's 1950 CBS Labs RX-43 CBS Color Receiver as seen on Ed Reitan's website.

Second photo is from a 70 inch 2012 Sharp Quatron LCD.

There are several different video releases of the Wizard of Oz (it's been discussed on VK before) , and there are wild chroma and general picture quality differences between them. The TBS banner at the bottom of that one shot makes me think those two photos were NOT taken from the same video source.

If you took that flatscreen screen shot, and ED did not take his from the same broadcast, then you are likely comparing apples to oranges, rather than apples to apples.

[tvcollector]

Thanks for info zeno.. I'll look into that one of these days..

[etype2]

Originally Posted by Electronic M

There are several different video releases of the Wizard of Oz (it's been discussed on VK before) , and there are wild chroma and general picture quality differences between them. The TBS banner at the bottom of that one shot makes me think those two photos were NOT taken from the same video source.

If you took that flatscreen screen shot, and ED did not take his from the same broadcast, then you are likely comparing apples to oranges, rather than apples to apples.

Yes. If you re-read my post, I explained where the two images came from.

The author of this thread said this in part "I have always sort of liked having a working "roundie" color set around for decades now, but i'm not sure why really. I personally think that they can make as decent a picture as most anything else I have seen, but I also think that the flat screens everyone has gone nuts over don't look that great really. Or not great enough for me to spend the money that they at least once commanded at retail."

I disagree that flat panels don't look great, that is why I posted the roundie screenshot and my screenshot.

I would love to see comparison screenshots of the same exact frame from owners of the CT-100 or any other roundie posted here. My screenshot is from a Direct TV satellite transmission. I suspect other screenshots will look better or worse then my shot, depending on the source.

BTW, I like roundies, too. :-)

[DaveWM]

I don't go around check flat screens often, but IIRC there was something about fast movement that did not look right to me. Maybe that is not the case anymore, but like I said I cant remember the last time I looked at one long enough to know if it was still the same.

[dtvmcdonald]

The best comparison is the one I did between an original on my computer
screen (i.e. no TV in between) and my CT-100:

http://www.videokarma.org/showthread...=262176&page=6

This is not a screen shot of the computer. Its the original. The
camera image of the CT-100 was tweeked in Photoshop with
the computer monitor sitting om the CT-100 until the images
on the CT-100 and the computer were identical except for brightness.

This is a test of TV resolution, color, and contrast. What you see
on YOUR computer is an accurate report on the DIFFERENCE between
the original as seen on the computer and the image on the TV.

[etype2]

Originally Posted by DaveWM

I don't go around check flat screens often, but IIRC there was something about fast movement that did not look right to me. Maybe that is not the case anymore, but like I said I cant remember the last time I looked at one long enough to know if it was still the same.

Your right. LCD panels have suffered from slow response time and viewing angles. Most of the early problems have been overcome in the newest, better quality panels, but to some degree those problems still persist.

I'm thinking about image quality, ie, color rendition and resolution as compared to the old roundies. Don't get me wrong, I have already said that I'm a fan of roundies. I have two so far and looking for a few more.

[Electronic M]

Originally Posted by etype2

Yes. If you re-read my post, I explained where the two images came from.

The author of this thread said this in part "I have always sort of liked having a working "roundie" color set around for decades now, but i'm not sure why really. I personally think that they can make as decent a picture as most anything else I have seen, but I also think that the flat screens everyone has gone nuts over don't look that great really. Or not great enough for me to spend the money that they at least once commanded at retail."

I disagree that flat panels don't look great, that is why I posted the roundie screenshot and my screenshot.

I would love to see comparison screenshots of the same exact frame from owners of the CT-100 or any other roundie posted here. My screenshot is from a Direct TV satellite transmission. I suspect other screenshots will look better or worse then my shot, depending on the source.

I just noticed another thing wrong in your comparison the 'roundy' picture is a field sequential set. Field sequential sets are scarce as hens teeth, and are a completely different (and less adjustable) process of color image generation (monochrome CRT with a color wheel spinning in in front of it) than a normal color CRT, and I'd dare say fall outside the most peoples definition of a roundy color set.

I wish I had time to re-read everything, but I don't.

I personally strongly dislike flatscreen sets. Non-Gaussian image elements don't look right to me (a certain softness and cross fade from picture element to picture element makes an image look better), I don't like (makes my eyes tired) the flashing nature of image refresh in a flat screen (versus the soft fade of a CRT), and don't get me started on viewing angle limitations of flat screens and all the maladies digital video has built in to it. If I ever go HD I'm getting an HD CRT set.

[etype2]

Originally Posted by dtvmcdonald

The best comparison is the one I did between an original on my computer
screen (i.e. no TV in between) and my CT-100:

http://www.videokarma.org/showthread...=262176&page=6

This is not a screen shot of the computer. Its the original. The
camera image of the CT-100 was tweeked in Photoshop with
the computer monitor sitting om the CT-100 until the images
on the CT-100 and the computer were identical except for brightness.

This is a test of TV resolution, color, and contrast. What you see
on YOUR computer is an accurate report on the DIFFERENCE between
the original as seen on the computer and the image on the TV.

I looked at the three sets of two images on that thread. If I understand correctly, the photos on the left are from the CT-100 and the clearer photos on the right are from the Sony LCD? Or am I wrong?

As to the screen shot I posted, if anyone has the DVD of the Wizard of Oz, the frame is at the 43 minute mark, just before Dorothy meets the scarecrow. You could take a screenshot on your roundie and post it here for comparison purposes.

[etype2]

Originally Posted by Electronic M

I just noticed another thing wrong in your comparison the 'roundy' picture is a field sequential set. Field sequential sets are scarce as hens teeth, and are a completely different (and less adjustable) process of color image generation (monochrome CRT with a color wheel spinning in in front of it) than a normal color CRT, and I'd dare say fall outside the most peoples definition of a roundy color set.

I wish I had time to re-read everything, but I don't.

I personally strongly dislike flatscreen sets. Non-Gaussian image elements don't look right to me (a certain softness and cross fade from picture element to picture element makes an image look better), I don't like (makes my eyes tired) the flashing nature of image refresh in a flat screen (versus the soft fade of a CRT), and don't get me started on viewing angle limitations of flat screens and all the maladies digital video has built in to it. If I ever go HD I'm getting an HD CRT set.

You are not telling me anything I don't know. I already said it was a field sequential set and that a better comparison would be to compare a CT-100 or other "modern" roundie from the 60's and sorry, if you don't read through my posts, then I have to respond.

Good luck with your future HD CRT.

[etype2]

I found this tread: http://www.videokarma.org/showthread...oz+screenshots

Beautiful screenshots on a CT-55. The first photo is of Dorothy from Oz on a roundie.