Videokarma.org

Go Back   Videokarma.org TV - Video - Vintage Television & Radio Forums > Early B&W and Projection TV

We appreciate your help

in keeping this site going.
Reply
 
Thread Tools Display Modes
  #61  
Old 02-23-2017, 04:54 PM
miniman82's Avatar
miniman82 miniman82 is offline
First Light: 1952-2011
 
Join Date: Jun 2009
Location: Great Mills, MD
Posts: 4,159
Wouldn't worry about it too much, long as the dag on your crt is in good condition it'll have way more capacity than the doorknob anyway.
__________________
Evolution...
Reply With Quote
  #62  
Old 02-23-2017, 11:45 PM
Crist Rigott Crist Rigott is offline
VideoKarma Member
 
Join Date: Oct 2015
Location: Waxahachie, TX
Posts: 1,506
The Dag is very good. Thanks.
Reply With Quote
  #63  
Old 02-23-2017, 11:46 PM
Crist Rigott Crist Rigott is offline
VideoKarma Member
 
Join Date: Oct 2015
Location: Waxahachie, TX
Posts: 1,506
I finished wiring the HV section tonight. Here are some pictures of the completed assembly.



Reply With Quote
  #64  
Old 02-25-2017, 10:56 AM
Crist Rigott Crist Rigott is offline
VideoKarma Member
 
Join Date: Oct 2015
Location: Waxahachie, TX
Posts: 1,506
Well, I decided to re-stuff my doorknob cap. I ordered 10 ea 470pf 20Kv caps from eBay for $6 shipped. http://www.ebay.com/itm/282085716087...%3AMEBIDX%3AIT

I cut off the bottom end right at the bottom portion of the main body. See the red arrow. I used my trusty band saw and took my time. No room for error.



Here is a picture after the bottom is cut off.





I then used my Dremel with a Robart 3/8 ball carbide cutter
http://robart.com/collections/hobby-...-8-ball-coarse
to grind out a cavity to house the new cap. I kept at least a 3/16 edge so there will be room for the epoxy to glue to when gluing on the bottom. I ground down till I can see the copper end post.



I then used some flux and solder to coat each end till my caps arrive.



More to follow when the caps get here.

Last edited by Crist Rigott; 02-25-2017 at 11:07 AM.
Reply With Quote
  #65  
Old 02-25-2017, 11:56 AM
old_coot88 old_coot88 is offline
VideoKarma Member
 
Join Date: Sep 2009
Posts: 2,541
Quote:
Originally Posted by miniman82 View Post
Wouldn't worry about it too much, long as the dag on your crt is in good condition it'll have way more capacity than the doorknob anyway.
Yeah, doorknobs came into use with metal cone CRTs which needed the extra filtering. When all-glass CRTs with internal/external aquadag came along, doorknobs kinda got 'grandfathered' along for a while, though not strictly needed.

Last edited by old_coot88; 02-25-2017 at 06:11 PM. Reason: TYPO
Reply With Quote
Audiokarma
  #66  
Old 02-25-2017, 05:40 PM
Crist Rigott Crist Rigott is offline
VideoKarma Member
 
Join Date: Oct 2015
Location: Waxahachie, TX
Posts: 1,506
Yeah, I know they are not really needed on this set. I'll re-stuff this one and reinstall for authenticity.
Reply With Quote
  #67  
Old 02-25-2017, 05:48 PM
Eric H's Avatar
Eric H Eric H is offline
Administrator
 
Join Date: Jun 2002
Location: So. Calif
Posts: 11,565
So what was inside this thing? Silver Mica?
Reply With Quote
  #68  
Old 02-25-2017, 06:31 PM
miniman82's Avatar
miniman82 miniman82 is offline
First Light: 1952-2011
 
Join Date: Jun 2009
Location: Great Mills, MD
Posts: 4,159
Metalized ceramic usually.
__________________
Evolution...
Reply With Quote
  #69  
Old 02-25-2017, 07:24 PM
Crist Rigott Crist Rigott is offline
VideoKarma Member
 
Join Date: Oct 2015
Location: Waxahachie, TX
Posts: 1,506
Just a little grey but mostly powered phenolic.
Reply With Quote
  #70  
Old 02-25-2017, 08:00 PM
old_coot88 old_coot88 is offline
VideoKarma Member
 
Join Date: Sep 2009
Posts: 2,541
I would be leery of re-using that casing because of leakage concerns.
Reply With Quote
Audiokarma
  #71  
Old 02-25-2017, 08:28 PM
Crist Rigott Crist Rigott is offline
VideoKarma Member
 
Join Date: Oct 2015
Location: Waxahachie, TX
Posts: 1,506
Quote:
Originally Posted by old_coot88 View Post
I would be leery of re-using that casing because of leakage concerns.
Why? When I solder in a new cap where will it leak?
Reply With Quote
  #72  
Old 02-25-2017, 09:51 PM
old_coot88 old_coot88 is offline
VideoKarma Member
 
Join Date: Sep 2009
Posts: 2,541
Now that the innard's exposed to ambient air/moisture, seems like it'd be prone to corona and arc-over inside. Or maybe I'm just being a fuddyduddy.
Reply With Quote
  #73  
Old 02-25-2017, 10:55 PM
Crist Rigott Crist Rigott is offline
VideoKarma Member
 
Join Date: Oct 2015
Location: Waxahachie, TX
Posts: 1,506
Quote:
Originally Posted by old_coot88 View Post
Now that the innard's exposed to ambient air/moisture, seems like it'd be prone to corona and arc-over inside. Or maybe I'm just being a fuddyduddy.
Maybe you are. But we will see together when I get the caps in.
Reply With Quote
  #74  
Old 02-25-2017, 11:03 PM
Crist Rigott Crist Rigott is offline
VideoKarma Member
 
Join Date: Oct 2015
Location: Waxahachie, TX
Posts: 1,506
I reassembled the TV to power it up. As a recap of what was done so far, was to replace the E-Caps, clean the on-off volume pot, clean the brightness contrast pots, clean the V and H hold pots, clean the focus pot, replace some caps and resistors.
I powered it up using my variac and all seemed good using my 5AXP4 CRT. (EDITT: I then installed the 7DP4 CRT.) After a little warm up, I adjusted the Ion Trap and had a very bright raster. The HV is good! I could hear good audio from channel 6 a local FM station, but when I had a good picture from my converter box, there was no audio. I could hear static and some clicking. A lot of hash when I changed channels. I haven't gone through the audio section yet.
Over all a decent picture and good audio but not together. Of course I have a lot of caps and resistors to replace. I'll do some more power ups as I go through each section. And I haven't even touched the tuner yet.

Here is what I have now:


A composite of before and after:

Last edited by Crist Rigott; 02-27-2017 at 09:54 AM. Reason: Clarified when I used the Ion Trap.
Reply With Quote
  #75  
Old 02-27-2017, 01:18 AM
EdKozk2 EdKozk2 is offline
Tinker
 
Join Date: Mar 2014
Location: Elkhorn, WI
Posts: 542
Hi Crist,
You said you heard clicking? Does it sound more like ticking, intermittent or continuous? I ask because if you stuffed the old doorknob with a modern ceramic or mica cap, you may have arcing between the cap leads. When I repaired my Admiral last fall I used a 15kv cap as a substitute for the old doorknob. When I first tested the set I would hear ticking. Lowering the brightness would increase the amount of ticking, increasing would decrease the amount. I had to operate the set on its' side and in darkness to see the source of the ticking. Turned out the gap between the capacitor leads right at the body of the cap needed a greater gap. The proper dressing of the leads solved the problem I had. I didn't reuse or stuff the old doorknob. I mounted the cap under the chassis.
Ed
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 05:54 PM.



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