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
  #241  
Old 08-14-2017, 03:34 PM
SwizzyMan's Avatar
SwizzyMan SwizzyMan is offline
Restoring an admiral c322
 
Join Date: Apr 2015
Location: Side Lake Mn
Posts: 886
I have been working on solving a ghosting issue in the picture. Checking resistors on the IF board only revealed 2 out of tolerance resistors. Two 68 ohms coming off the cathode of the 6az8 IF tubes then to ground. Next thing I suspected was the 1n60, but it tests fine on the diode test. Should I still replace it? I need to check around the video amp tubes now.
__________________

Admiral C322C2 Regent (Restoring)
RCA CTC-7 Pensbury (Restored)
RCA CTC-5 Westcott (Restored)
CRA CTC--4 Director 21 (Restoring)
Reply With Quote
  #242  
Old 08-14-2017, 04:33 PM
SwizzyMan's Avatar
SwizzyMan SwizzyMan is offline
Restoring an admiral c322
 
Join Date: Apr 2015
Location: Side Lake Mn
Posts: 886
Found an open inductor on the video out tube. L72 on sams 180 Microhenry 9.5ohm. Is this an appropriate replacement? http://www.mouser.com/ProductDetail/...o%2f1lu29zY%3d
__________________

Admiral C322C2 Regent (Restoring)
RCA CTC-7 Pensbury (Restored)
RCA CTC-5 Westcott (Restored)
CRA CTC--4 Director 21 (Restoring)
Reply With Quote
  #243  
Old 08-14-2017, 07:29 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: 7,184
Quote:
Originally Posted by SwizzyMan View Post
Found an open inductor on the video out tube. L72 on sams 180 Microhenry 9.5ohm. Is this an appropriate replacement? http://www.mouser.com/ProductDetail/...o%2f1lu29zY%3d
Looks like it should work fine.
__________________
www.bretl.com
Old TV literature, New York World's Fair, and other miscellany
Reply With Quote
  #244  
Old 08-14-2017, 07:35 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: 7,184
Did you check L71 and R68 also?

Edit: also R69, L70, and the contrast control - these are all things that load the input or output of the delay line and need to match the impedance properly to prevent echos.
__________________
www.bretl.com
Old TV literature, New York World's Fair, and other miscellany

Last edited by old_tv_nut; 08-14-2017 at 07:38 PM.
Reply With Quote
  #245  
Old 08-14-2017, 08:11 PM
SwizzyMan's Avatar
SwizzyMan SwizzyMan is offline
Restoring an admiral c322
 
Join Date: Apr 2015
Location: Side Lake Mn
Posts: 886
Quote:
Originally Posted by old_tv_nut View Post
Did you check L71 and R68 also?

Edit: also R69, L70, and the contrast control - these are all things that load the input or output of the delay line and need to match the impedance properly to prevent echos.
Everything tests fine except for maybe the contrast control. It reads 21ohms at full clockwise and about 1k at full counter-clockwise. I dont think that is right.
__________________

Admiral C322C2 Regent (Restoring)
RCA CTC-7 Pensbury (Restored)
RCA CTC-5 Westcott (Restored)
CRA CTC--4 Director 21 (Restoring)
Reply With Quote
Audiokarma
  #246  
Old 08-14-2017, 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: 7,184
You didn't say which terminals of the contrast you are connected to, but if you don't disconnect one end, you will read a bunch of other things in parallel, particularly the delay line and its 1.2K input resistor. So, the 1K reading is probably normal or close to it for an in-circuit reading. I would just wait to see what the replacement coil does for your ghosting, rather than disconnecting things unnecessarily.
__________________
www.bretl.com
Old TV literature, New York World's Fair, and other miscellany
Reply With Quote
  #247  
Old 08-15-2017, 04:30 PM
SwizzyMan's Avatar
SwizzyMan SwizzyMan is offline
Restoring an admiral c322
 
Join Date: Apr 2015
Location: Side Lake Mn
Posts: 886
Just ordered new coils and resistors. Found another coil that was bad L94 that read about 1 meg when it should be 27 ohm.
__________________

Admiral C322C2 Regent (Restoring)
RCA CTC-7 Pensbury (Restored)
RCA CTC-5 Westcott (Restored)
CRA CTC--4 Director 21 (Restoring)
Reply With Quote
  #248  
Old 08-15-2017, 05:34 PM
timmy's Avatar
timmy timmy is offline
VideoKarma Member
 
Join Date: Jan 2011
Location: ferndale ny
Posts: 3,504
Wow that set is going to be better then originally new once it's done, lots of troubleshooting. Looking good keep at it .
Reply With Quote
  #249  
Old 08-15-2017, 06:04 PM
old_coot88 old_coot88 is offline
VideoKarma Member
 
Join Date: Sep 2009
Posts: 2,541
Quote:
Originally Posted by SwizzyMan View Post
I have been working on solving a ghosting issue in the picture.
By ghosting, do you mean ringing (parasitic amplitude ripples tagging after fine detail in the pic)? If so, try subbing the last IF tube if you haven't already. It can cause ringing even if it tests good on a tester.
Reply With Quote
  #250  
Old 08-15-2017, 07:56 PM
SwizzyMan's Avatar
SwizzyMan SwizzyMan is offline
Restoring an admiral c322
 
Join Date: Apr 2015
Location: Side Lake Mn
Posts: 886
Quote:
Originally Posted by old_coot88 View Post
By ghosting, do you mean ringing (parasitic amplitude ripples tagging after fine detail in the pic)? If so, try subbing the last IF tube if you haven't already. It can cause ringing even if it tests good on a tester.
Yes. I believe I did try subbing that tube with no difference.
__________________

Admiral C322C2 Regent (Restoring)
RCA CTC-7 Pensbury (Restored)
RCA CTC-5 Westcott (Restored)
CRA CTC--4 Director 21 (Restoring)
Reply With Quote
Audiokarma
  #251  
Old 08-18-2017, 06:24 PM
miniman82's Avatar
miniman82 miniman82 is offline
First Light: 1952-2011
 
Join Date: Jun 2009
Location: Great Mills, MD
Posts: 4,159
This can also be caused be improper termination of the delay line, check all parts for value on either end of it.
__________________
Evolution...
Reply With Quote
  #252  
Old 08-19-2017, 04:11 PM
SwizzyMan's Avatar
SwizzyMan SwizzyMan is offline
Restoring an admiral c322
 
Join Date: Apr 2015
Location: Side Lake Mn
Posts: 886
So adding the 180uh choke in place of the open one (L72) makes the ghosting WORSE! Ugh! Something else has to be causing this then. Left photo is with no coil, right is with coil attached in circuit.
Attached Images
File Type: jpg 20170819_170104.jpg (85.0 KB, 33 views)
File Type: jpg 20170819_170126.jpg (92.3 KB, 33 views)
__________________

Admiral C322C2 Regent (Restoring)
RCA CTC-7 Pensbury (Restored)
RCA CTC-5 Westcott (Restored)
CRA CTC--4 Director 21 (Restoring)
Reply With Quote
  #253  
Old 08-19-2017, 07:12 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: 7,184
Suggestions:

1) make sure the value isn't off by a decimal place or something
2) check for open resistor in parallel with either L72 and/or L71

If it's not those, check all other parallel L-R combos in the video amp chain.
__________________
www.bretl.com
Old TV literature, New York World's Fair, and other miscellany
Reply With Quote
  #254  
Old 08-19-2017, 08:00 PM
SwizzyMan's Avatar
SwizzyMan SwizzyMan is offline
Restoring an admiral c322
 
Join Date: Apr 2015
Location: Side Lake Mn
Posts: 886
Quote:
Originally Posted by old_tv_nut View Post
Suggestions:

1) make sure the value isn't off by a decimal place or something
2) check for open resistor in parallel with either L72 and/or L71

If it's not those, check all other parallel L-R combos in the video amp chain.
Value is fine. Checked all coils and resistors that may be in parallel with them and they all check fine except for a coil on the B-Y amp that reads 1.2 meg, but I dont think that one really matters for my current problem. I hope its not the delay line causing this!
__________________

Admiral C322C2 Regent (Restoring)
RCA CTC-7 Pensbury (Restored)
RCA CTC-5 Westcott (Restored)
CRA CTC--4 Director 21 (Restoring)

Last edited by SwizzyMan; 08-19-2017 at 08:05 PM.
Reply With Quote
  #255  
Old 08-19-2017, 08:26 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: 7,184
Quote:
Originally Posted by SwizzyMan View Post
Value is fine. Checked all coils and resistors that may be in parallel with them and they all check fine except for a coil on the B-Y amp that reads 1.2 meg, but I dont think that one really matters for my current problem. I hope its not the delay line causing this!
Are these components on a PC bOard? Maybe a bad solder joint? Try bridging a resistor directly across the coil?
__________________
www.bretl.com
Old TV literature, New York World's Fair, and other miscellany
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 06:33 PM.



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