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
  #16  
Old 02-28-2017, 11:27 AM
bandersen's Avatar
bandersen bandersen is offline
Setting up a new workshop
 
Join Date: Mar 2009
Location: Chicago, IL
Posts: 7,100
I think you guys are referring to the coil on the plate of the damper tube ? It doesn't appear to be adjustable.


I have a nifty SECO HC8 cathode current monitor I can use.
__________________
Here are my Vintage Radio & TV YouTube Channel and Photo Gallery
Reply With Quote
  #17  
Old 02-28-2017, 12:17 PM
Kevin Kuehn's Avatar
Kevin Kuehn Kevin Kuehn is offline
Workin' Late Again
 
Join Date: Jan 2011
Location: WI
Posts: 2,665
This is the 25LC30 circuit everyone's been woopin' and hollerin' about
Looks like you could add in your own horizontal efficiency coil.

Reply With Quote
  #18  
Old 02-28-2017, 12:45 PM
bandersen's Avatar
bandersen bandersen is offline
Setting up a new workshop
 
Join Date: Mar 2009
Location: Chicago, IL
Posts: 7,100
Thanks. Looks like I have the simplified design. I'll see about adding that in when I pull the chassis. Wouldn't be surprised if there's space for the extra components.
__________________
Here are my Vintage Radio & TV YouTube Channel and Photo Gallery
Reply With Quote
  #19  
Old 02-28-2017, 08:20 PM
dieseljeep dieseljeep is offline
VideoKarma Member
 
Join Date: Jul 2010
Posts: 5,540
Quote:
Originally Posted by bandersen View Post
Thanks. Looks like I have the simplified design. I'll see about adding that in when I pull the chassis. Wouldn't be surprised if there's space for the extra components.
Get rid of the R35, while you're at it. It's a common failure item and not needed. 1500 ohm, 1 watt.
Reply With Quote
  #20  
Old 02-28-2017, 09:14 PM
Kevin Kuehn's Avatar
Kevin Kuehn Kevin Kuehn is offline
Workin' Late Again
 
Join Date: Jan 2011
Location: WI
Posts: 2,665
Quote:
Originally Posted by dieseljeep View Post
Get rid of the R35, while you're at it. It's a common failure item and not needed. 1500 ohm, 1 watt.
Isn't that suppose to act as a current limiter in the event something goes terribly wrong?
Reply With Quote
Audiokarma
  #21  
Old 02-28-2017, 09:30 PM
dieseljeep dieseljeep is offline
VideoKarma Member
 
Join Date: Jul 2010
Posts: 5,540
Quote:
Originally Posted by Kevin Kuehn View Post
Isn't that suppose to act as a current limiter in the event something goes terribly wrong?
Zenith engineering recommended eliminating it. It was the subject of a thread, quite a while ago.
Reply With Quote
  #22  
Old 03-01-2017, 12:42 AM
Robert Grant's Avatar
Robert Grant Robert Grant is offline
VideoKarma Member
 
Join Date: Feb 2008
Location: Monroe County, MI
Posts: 410
At first, I thought you found the very same model I have, only realizing that mine has a wood cabinet with its front legs consisting of extensions of the front face of the cabinet continuing to floor level.

I had been working on it, after gathering a new tube for every tube except the 21FJ (which tests good), but there had been a lot of nonstandard work under the chassis, and something went "pop" one night I was testing it out.

It's quite compact for a color roundie with legs. I think I can say with certainty that it is the only color roundie that has ever been transported in a Prius.

Last edited by Robert Grant; 03-01-2017 at 12:48 AM.
Reply With Quote
  #23  
Old 03-01-2017, 09:38 AM
Kevin Kuehn's Avatar
Kevin Kuehn Kevin Kuehn is offline
Workin' Late Again
 
Join Date: Jan 2011
Location: WI
Posts: 2,665
Quote:
Originally Posted by dieseljeep View Post
Zenith engineering recommended eliminating it. It was the subject of a thread, quite a while ago.
Robert Goodman also says to get it out of there.(Zenith Color TV Service Manual,Vol I,Tab Books) Same book Bandersen showed us earlier. Robert mentions a couple different situations, which at first impression leads one to believe he's talking about two different resistors, however there only seems to be that one 1.5K associated with the HV?

Reply With Quote
  #24  
Old 03-01-2017, 10:58 AM
bandersen's Avatar
bandersen bandersen is offline
Setting up a new workshop
 
Join Date: Mar 2009
Location: Chicago, IL
Posts: 7,100
Thanks for the info. It'll be interesting to see if that resistor has been removed or jumpered.
__________________
Here are my Vintage Radio & TV YouTube Channel and Photo Gallery
Reply With Quote
  #25  
Old 03-02-2017, 01:49 AM
Tubejunke's Avatar
Tubejunke Tubejunke is offline
VideoKarma Member
 
Join Date: Apr 2003
Location: Martinsville, VA
Posts: 1,782
Yep, my resistor popped under that rectifier. The socket was also burned which is why there was an annoying hissing before the repair which was replacement of the socket and jumping the pins where the resistor would have been. This is a good thread! It's making me think of working on mine again.
__________________
"Face piles of trials with smiles, for it riles them to believe that you perceive the web they weave, and keep on thinking free"
Reply With Quote
Audiokarma
  #26  
Old 03-06-2017, 11:39 AM
bandersen's Avatar
bandersen bandersen is offline
Setting up a new workshop
 
Join Date: Mar 2009
Location: Chicago, IL
Posts: 7,100
I got a copy of the Sams I'm itching to pop the back off this set, but I've got a ton of post move stuff to do first including setting up a new workbench.

__________________
Here are my Vintage Radio & TV YouTube Channel and Photo Gallery
Reply With Quote
  #27  
Old 03-08-2017, 10:00 AM
bandersen's Avatar
bandersen bandersen is offline
Setting up a new workshop
 
Join Date: Mar 2009
Location: Chicago, IL
Posts: 7,100
I popped the back off last night and took some more pictures. I like how the back is held on with clips rather than screws. Very easy to get on and off.



So far I see a mix of bumblebee and maroon caps.
I assume the bumblebee are paper inside and should be replaced but what about the maroon type ? Are these plastic film and generally OK or should I shotgun them ?


Also any thoughts about the missing x-ray shielding ? Would some galvanized or aluminum sheet metal be sufficient ?
__________________
Here are my Vintage Radio & TV YouTube Channel and Photo Gallery
Reply With Quote
  #28  
Old 03-08-2017, 02:27 PM
Findm-Keepm's Avatar
Findm-Keepm Findm-Keepm is offline
Slave to a CTC-16
 
Join Date: Jun 2007
Posts: 2,502
The Maroon Elmencos can stay - they are film, just like an Orange Drop. RCA and Zenith loved them - I've never seen one go bad.

As to shielding, any ferrous metal will work - I've used perforated (1/16" holes) metal before - came straight off of an old Phase Angle Voltmeter. Also, make sure you have the 6BK4C regulator, or a 6EL4A. They are the regulator tubes with the longer anode that provides the optimum X-ray protection. Of note, patented by a female RCA engineer!!
__________________
Brian
"Capacitor Cosmetologist since 1979"

When fuses go to work, they quit.


Make Safety your first thought, not your last.

Last edited by Findm-Keepm; 03-08-2017 at 02:31 PM.
Reply With Quote
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 05:19 PM.



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