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 01-24-2016, 09:37 AM
OS X OS X is offline
< RCA CTC-5
 
Join Date: Jan 2012
Location: Buffalo,NY
Posts: 116
Unhappy CTC-5 No luminance.

I just bought a restored CTC-5 and I'm having a problem with it, I'm getting no luminance but good chroma. I don't know much about color sets so I'm trying to get a idea what might be causing it? The CRT is good so I don't think it's anything with that.
Attached Images
File Type: jpg 20160123_144707-1.jpg (56.0 KB, 117 views)
File Type: jpg 20160123_145000.jpg (35.1 KB, 72 views)
File Type: jpg 20160123_144755.jpg (35.2 KB, 43 views)
File Type: jpg 20160123_144624.jpg (30.0 KB, 41 views)
File Type: jpg 20160123_145007.jpg (33.2 KB, 59 views)
Reply With Quote
  #2  
Old 01-24-2016, 09:45 AM
dtvmcdonald's Avatar
dtvmcdonald dtvmcdonald is offline
VideoKarma Member
 
Join Date: Nov 2012
Posts: 1,191
There is both chroma and luma drive in those pictures, in approximately
correct ratio. The CRT screen and brightness and drive (per color) adjustments
just need correct adjustment, assuming of course that nothing broke between
restoration and your buying it.
Reply With Quote
  #3  
Old 01-24-2016, 10:00 AM
OS X OS X is offline
< RCA CTC-5
 
Join Date: Jan 2012
Location: Buffalo,NY
Posts: 116
Quote:
Originally Posted by dtvmcdonald View Post
There is both chroma and luma drive in those pictures, in approximately
correct ratio. The CRT screen and brightness and drive (per color) adjustments
just need correct adjustment, assuming of course that nothing broke between
restoration and your buying it.
Thanks and I'm hoping that's all it is. I guess I need to start with feeding it a direct signal from a DVD player or I might even try and get a signal pattern generator. For how good the CRT tests I do have the brightness and contrast turned up pretty high to get that picture I wouldn't be surprised if the drive controls got bumped somewhere along the line. Also here's a video of it https://www.youtube.com/watch?v=EY3R3IIlJas
Reply With Quote
  #4  
Old 01-24-2016, 10:25 AM
SwizzyMan's Avatar
SwizzyMan SwizzyMan is offline
Restoring an admiral c322
 
Join Date: Apr 2015
Location: Side Lake Mn
Posts: 886
Check the delay line or the 12by7a tube or parts associated with it.
__________________

Admiral C322C2 Regent (Restoring)
RCA CTC-7 Pensbury (Restored)
RCA CTC-5 Westcott (Restored)
CRA CTC--4 Director 21 (Restoring)
Reply With Quote
  #5  
Old 01-24-2016, 11:13 AM
OS X OS X is offline
< RCA CTC-5
 
Join Date: Jan 2012
Location: Buffalo,NY
Posts: 116
Quote:
Originally Posted by SwizzyMan View Post
Check the delay line or the 12by7a tube or parts associated with it.
I believe this set has all its original tubes so it very well may be weak. I guess if I can get my hands on a NOS 12BY7A I'll give that a try to start. Also does anyone have the service manual for this set they would like to sell?
Reply With Quote
Audiokarma
  #6  
Old 01-24-2016, 11:17 AM
Kamakiri's Avatar
Kamakiri Kamakiri is offline
Administrator
 
Join Date: Jun 2002
Location: Buffalo, New York
Posts: 5,109
I gots NOS 12BY7As
__________________
"Restoring a tube TV is like going to war. A color one is like a land war in Asia."
Reply With Quote
  #7  
Old 01-24-2016, 01:23 PM
Electronic M's Avatar
Electronic M Electronic M is offline
M is for Memory
 
Join Date: Jan 2011
Location: Pewaukee/Delafield Wi
Posts: 14,758
Quote:
Originally Posted by OS X View Post
I believe this set has all its original tubes so it very well may be weak. I guess if I can get my hands on a NOS 12BY7A I'll give that a try to start. Also does anyone have the service manual for this set they would like to sell?
Might be time to buy a tube tester.
__________________
Tom C.

Zenith: The quality stays in EVEN after the name falls off!
What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4
Reply With Quote
  #8  
Old 01-24-2016, 03:46 PM
Kamakiri's Avatar
Kamakiri Kamakiri is offline
Administrator
 
Join Date: Jun 2002
Location: Buffalo, New York
Posts: 5,109
Pretty sure he's got one, but I don't think it does many of the post-1960 tubes. We have to get together anyway, he has a GE color portable for me from his recent trip to Detroit
__________________
"Restoring a tube TV is like going to war. A color one is like a land war in Asia."
Reply With Quote
  #9  
Old 01-24-2016, 07:59 PM
oldtvman's Avatar
oldtvman oldtvman is offline
Larry Melton (oldtvman)
 
Join Date: Jan 2005
Location: Mishawaka, Indiana
Posts: 772
That should be fairly easy to trace down with a scope. Straight forward video problem
__________________
[IMG]
Reply With Quote
  #10  
Old 01-24-2016, 08:49 PM
OS X OS X is offline
< RCA CTC-5
 
Join Date: Jan 2012
Location: Buffalo,NY
Posts: 116
Smile

Quote:
Originally Posted by Electronic M View Post
Might be time to buy a tube tester.
I do have one and its a rapid tube tester model 82A it pretty much only tests emissions but works ok for a low end tube tester, After looking online for around a hour today I found the tube setup list for this tester as mine is missing at least 1 page and sure enough the 12BY7A is on there, I tested it and it is weak it's on the hi end in the middle questionable area on the tester. I'll try to test all the tubes in this set the tester supports

Quote:
Originally Posted by Kamakiri
I gots NOS 12BY7As
Look's like the CTC-5 will need one I was able to test it after all and the 12BY7A test weak. And I'll bring your GE over for you as well I got side tracked with the last minute road trip to get the CTC-5 and didn't do much of nothing this past week Lol.

Quote:
Originally Posted by oldtvman View Post
That should be fairly easy to trace down with a scope. Straight forward video problem
unfortunately I don't have a scope I'm still building my collection of test equipment, right now I only have the very basics. Hopefully a new 12BY7A will help, If not I guess I'll have to get a scope.
Reply With Quote
Audiokarma
  #11  
Old 01-25-2016, 12:39 AM
old_coot88 old_coot88 is offline
VideoKarma Member
 
Join Date: Sep 2009
Posts: 2,541
Quote:
Originally Posted by OS X View Post
I just bought a restored CTC-5 and I'm having a problem with it, I'm getting no luminance but good chroma. I don't know much about color sets so I'm trying to get a idea what might be causing it? The CRT is good so I don't think it's anything with that.
Just to make one point clear: Luminance or 'Luma' refers to the B&W video component of the picture. That is, if you turn the color completely off, there'll still be a normal B&W pic.
Luma doesn't refer to brightness of the raster itself.
Reply With Quote
  #12  
Old 01-25-2016, 07:35 AM
miniman82's Avatar
miniman82 miniman82 is offline
First Light: 1952-2011
 
Join Date: Jun 2009
Location: Great Mills, MD
Posts: 4,159
Though if the video (Y) amp tubes are weak, a dim raster can be a symptom.
__________________
Evolution...
Reply With Quote
  #13  
Old 01-25-2016, 07:47 AM
Kamakiri's Avatar
Kamakiri Kamakiri is offline
Administrator
 
Join Date: Jun 2002
Location: Buffalo, New York
Posts: 5,109
Quote:
Originally Posted by OS X View Post
Look's like the CTC-5 will need one I was able to test it after all and the 12BY7A test weak. And I'll bring your GE over for you as well I got side tracked with the last minute road trip to get the CTC-5 and didn't do much of nothing this past week Lol.
Test all the tubes in the sets you just got and tomorrow you can come shopping.
__________________
"Restoring a tube TV is like going to war. A color one is like a land war in Asia."
Reply With Quote
  #14  
Old 01-25-2016, 10:44 AM
old_coot88 old_coot88 is offline
VideoKarma Member
 
Join Date: Sep 2009
Posts: 2,541
Quote:
Originally Posted by miniman82 View Post
Though if the video (Y) amp tubes are weak, a dim raster can be a symptom.
Right you are.
Reply With Quote
  #15  
Old 01-25-2016, 03:30 PM
wa2ise's Avatar
wa2ise wa2ise is offline
VideoKarma Member
 
Join Date: Dec 2002
Location: USA
Posts: 3,147
All the unobtanium parts appear to be working fine (CRT, flyback, power transformer and such) and what is broken should be easily obtained.
__________________
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 03:29 AM.



Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
©Copyright 2012 VideoKarma.org, All rights reserved.