Videokarma.org

Go Back   Videokarma.org TV - Video - Vintage Television & Radio Forums > Early Color Television

We appreciate your help

in keeping this site going.
Reply
 
Thread Tools Display Modes
  #1  
Old 04-26-2013, 02:56 PM
Tomcomm's Avatar
Tomcomm Tomcomm is offline
VideoKarma Member
 
Join Date: Nov 2007
Location: Santa Ynez, CA
Posts: 212
21CT55 Screen-Shot Test

Attempting to post full monitor screen size on VK Forum postings.

[/URL]

[/URL]


[/URL]


[[/URL]

[/URL]

[/UR]

[/URL]

Last edited by Tomcomm; 04-28-2013 at 12:36 PM.
Reply With Quote
  #2  
Old 04-26-2013, 03:05 PM
zenithfan1's Avatar
zenithfan1 zenithfan1 is offline
Mark
 
Join Date: Jan 2008
Location: Kenosha, Wisconsin
Posts: 4,140
Hey Tom, that CT-55 has one hell of a picture on it.
__________________
My TV page and YouTube channel
Kyocera R-661, Yamaha RX-V2200
National Panasonic SA-5800
Sansui 1000a, 1000, SAX-200, 5050, 9090DB, 881, SR-636, SC-3000, AT-20
Pioneer SX-1500TD, ER-420, SM-B201
Akai 4000DS Mk-II
Motorola SK77W-2Z tube console
Reply With Quote
  #3  
Old 04-26-2013, 03:46 PM
kvflyer kvflyer is offline
VideoKarma Member
 
Join Date: Nov 2006
Location: Catonsville, MD, USA
Posts: 800
You know, I thought that as color television matured, the colors etc. would have improved exponentially. Obviously, I was wrong. I remember early color but didn't know about the differences.

What CRT has the "correct" colors, red especially and when did it change please? For instance, was the 15GP22 the only one with correct colors, or does a 21CPY22 have the same colors. I realize I skipped ahead by several steps.

Just wondering...


Thanks!
Reply With Quote
  #4  
Old 04-27-2013, 09:08 PM
old_tv_nut's Avatar
old_tv_nut old_tv_nut is offline
See yourself on Color TV!
 
Join Date: Jul 2004
Location: Rancho Sahuarita
Posts: 4,289
Quote:
Originally Posted by kvflyer View Post
You know, I thought that as color television matured, the colors etc. would have improved exponentially. Obviously, I was wrong. I remember early color but didn't know about the differences.

What CRT has the "correct" colors, red especially and when did it change please? For instance, was the 15GP22 the only one with correct colors, or does a 21CPY22 have the same colors. I realize I skipped ahead by several steps.

Just wondering...


Thanks!
See post #12 in this thread:
http://www.videokarma.org/showthread...color+phosphor

The only correct NTSC tubes were the 15GP22 and the early 21AXP22's.

The main difference that affected both greens and reds was the change from P1 green to sulfide green . The sulfide red was somewhat more orangy than other reds, but the rare-earth reds usually are quite close to NTSC red.

NTSC red, by the way, is a bit orange - it can reproduce car tail lights but not traffic signal red.

Also, when the NTSC blue, which is somewhat towards cyan, was replaced by more-violet sulfide blue, this affected flesh tones by moving yellows towards green.

This has been a mishmosh in NTSC for all tubes after the 15GP22 and 21AXP22, and only PAL and now HDTV have got it right by changing the cameras to match the modern phosphors. You can see "chery red" as distinct from other reds with the modern phosphors if the camera is designed for them. Otherwise, the approximate corrections built into NTSC sets result in overdriving the bright reds, making them all overly bright and the same color as the red phosphor.

Having a 15GP22 no longer guarantees you correct color on NTSC sources, since at the same time receiver manufacturers were putting in compensation, camera manufacturers were fudging to get acceptable pictures on monitors with the new phosphors and monitor manufacturers were including switchable matrices that could either demodulate straight (but with the modern phosphors) or with an electrical correction similar to home receivers.

This was like the factory time keeper blowing the whistle based on the train departure while the train conductor set his watch by the factory whistle.

The original TK-41 cameras had no matrixing to tweak, but relied on careful selection of trimming filters in each color channel to get the best response for NTSC phosphors. This was a major reason why their optics were so inefficient. Later versions had more efficient wider-passband prism optics, but still no matrixing, and the prism passbands were still optimized for NTSC phosphors. So at this time (early 60s) the futzing was all in the receivers. As soon as Plumbicon cameras appeared, they had to have matrixing because the deep red response was so poor; and the good signal-to-noise ratio of Plumbicons made matrixing possible without excessive noise. The receiver manufacturers had been playing with the color for some years, but now the camera designers were too. This is the point at which PAL standards were developed, so they had the option to make the receivers demodulate without special compensation and do the proper compensation for the new phosphors in the cameras.
NTSC countries were not so blessed, because they already had a population of receivers with various approximate compensation for the new phosphors.
Reply With Quote
  #5  
Old 04-28-2013, 10:26 AM
kvflyer kvflyer is offline
VideoKarma Member
 
Join Date: Nov 2006
Location: Catonsville, MD, USA
Posts: 800
Quote:
Originally Posted by old_tv_nut View Post
See post #12 in this thread:
http://www.videokarma.org/showthread...color+phosphor

The only correct NTSC tubes were the 15GP22 and the early 21AXP22's.

The main difference that affected both greens and reds was the change from P1 green to sulfide green . ...
Thank you very, very much for answering that question in great detail. I have a CTC-9 in queue for restoration. But it, as you must know, does not have the 21AXP22 in it, rather the 21CYP22. And, I hold no hope to ever have access to a 15GP22!

In reading this thread and the thread that was linked, it sure does bring back memories. I remember when color TV was a new thing. I just didn't remember the change in color. But I sure do know what you are talking about. I had a Heathkit GR-2000 (I think that is the number) that had a Zenith CRT in it. I always felt that the colors favored earthtones. I thought that it was similar to the 70s obsession with browns and oranges. No bright blues, greens or reds.

I also remember working for EJ Korvette. I worked in the Audio Dept. which was right next to what they called "Major Appliances". In that dept., they had a room with doors that had all of the color sets in it. It was a very dim room. Hmmm, there's a surprise! I just hope to one day have a set with the early phosphors in it.

Again, thanks for explaining and taking the time to search and post.
Reply With Quote
Audiokarma
  #6  
Old 04-28-2013, 03:26 PM
Tomcomm's Avatar
Tomcomm Tomcomm is offline
VideoKarma Member
 
Join Date: Nov 2007
Location: Santa Ynez, CA
Posts: 212
21CT55 Screen-Shot Test

Thanks for your responses. In reviewing this thread I noticed the third screen shot of my Beth, Andy and Baby Jack was not interlaced. So I replaced it with a shot having proper interlace. This correction emphasizes my contention all posted Roundy screen shots should be taken in total darkness, sized full edge to edge and presented on the viewing monitor full size edge to edge. Conveying cabinet detail is a separate issue and should be taken full room lighting. Since I have no cabinet I have no problem with this. I also added two more good shots plus a saturated color bar shot. Check it out. The bar colors appear quite accurate on my 19 inch Acer LCD monitor. The red bar’s hue is virtually indistinguishable from my clock’s red led numerical dial color hue. The CRT is a 21FBP22A rare-earth with a white-paper gray face plate. I always considered this CRT’s red to be more “pure” compared to my Sony Pro monitor which specs SMPTE-C color phosphor. The Sony’s red bar is more “orangish” like all my other CRT TVs.

Last edited by Tomcomm; 09-25-2017 at 04:12 PM.
Reply With Quote
  #7  
Old 05-01-2014, 05:44 PM
bozey45 bozey45 is offline
VideoKarma Member
 
Join Date: Oct 2005
Location: Pasco County Florida
Posts: 94
Heathkit GR-2000

Yes, it was the GR-2000, the 25 inch set. I still have it in the early American style large cabinet, built it in 1976.
Reply With Quote
  #8  
Old 04-26-2013, 04:26 PM
Sandy G's Avatar
Sandy G Sandy G is offline
Spiteful Old Cuss
 
Join Date: May 2003
Location: Rogersville, Tennessee
Posts: 9,098
"Glorious Lollipop Color"....(grin)
__________________
Benevolent Despot
Reply With Quote
  #9  
Old 04-26-2013, 06:28 PM
Username1's Avatar
Username1 Username1 is offline
Not sure how I got here.
 
Join Date: Dec 2009
Location: Orange County NY
Posts: 3,466
Nice job, very good picture.... good convergence!

me likey.....
__________________
Yes you can call me "Squirrel boy"
Reply With Quote
  #10  
Old 04-26-2013, 09:48 PM
sampson159's Avatar
sampson159 sampson159 is offline
sampson159
 
Join Date: Sep 2007
Location: columbus,ohio
Posts: 2,092
can you believe the saturation and the fleshtones?awesome pics.this is the pinnacle of real color tv.loving this!
Reply With Quote
Audiokarma
  #11  
Old 04-26-2013, 09:59 PM
Sandy G's Avatar
Sandy G Sandy G is offline
Spiteful Old Cuss
 
Join Date: May 2003
Location: Rogersville, Tennessee
Posts: 9,098
Amazing picture, & it was done w/o all those hokey "Color Correction" circuits they had later..They HAD virtual HDTV in '54, they just didn't realize it..
__________________
Benevolent Despot
Reply With Quote
  #12  
Old 04-27-2013, 02:18 AM
ChrisW6ATV's Avatar
ChrisW6ATV ChrisW6ATV is offline
Another CT-100 lives!
 
Join Date: Feb 2007
Location: Hayward, Cal. USA
Posts: 3,310
Very nice screen shots!

The color "correction" circuits were really color "poor adjustment compensation" circuits. Ruin a good thing for the sake of making it "good enough for average, sloppy users". Way too much of the world is made that way, it seems.
__________________
Chris

Quote from another forum: "(Antique TV collecting) always seemed to me to be a fringe hobby that only weirdos did."
Reply With Quote
  #13  
Old 04-27-2013, 06:48 AM
Mal Fuller Mal Fuller is offline
VideoKarma Member
 
Join Date: Jun 2011
Posts: 111
What's wrong with this picture?
I remember that the CTC2B chassis sat flat in its cabinet and that the CTC4 chassis was the first to be mounted vertically as shown.
Reply With Quote
  #14  
Old 04-29-2013, 07:34 PM
ChrisW6ATV's Avatar
ChrisW6ATV ChrisW6ATV is offline
Another CT-100 lives!
 
Join Date: Feb 2007
Location: Hayward, Cal. USA
Posts: 3,310
Quote:
Originally Posted by Mal Fuller View Post
What's wrong with this picture?
I remember that the CTC2B chassis sat flat in its cabinet and that the CTC4 chassis was the first to be mounted vertically as shown.
Tom explained at one time, that he modified his CTC-2B by repositioning the chassis vertically (and discarding the cabinet if he ever had it) in the 1960s when he first got that set.
__________________
Chris

Quote from another forum: "(Antique TV collecting) always seemed to me to be a fringe hobby that only weirdos did."
Reply With Quote
  #15  
Old 04-30-2013, 02:24 PM
Zenith26kc20's Avatar
Zenith26kc20 Zenith26kc20 is offline
VideoKarma Member
 
Join Date: Apr 2009
Location: New Orleans
Posts: 801
If I remember right doesn't this set have video inputs installed?
I remember a thread about it a while ago. If so, can I get a link to the thread?
Reply With Quote
Audiokarma
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 04:39 AM.



Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
ęCopyright 2012 VideoKarma.org, All rights reserved.