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
  #496  
Old 07-26-2012, 07:42 PM
ctc17 ctc17 is offline
VideoKarma Member
 
Join Date: Jul 2009
Posts: 1,617
So far I have had a 6GH8, 6JE6 and 21FJ crack and go to air after returning a retired set to service. None of these tubes were being touched, they just went to air while the set was off after I started using the set again.
Reply With Quote
  #497  
Old 07-26-2012, 11:20 PM
Eric H's Avatar
Eric H Eric H is online now
Administrator
 
Join Date: Jun 2002
Location: So. Calif
Posts: 11,296
Quote:
Originally Posted by ctc17 View Post
So far I have had a 6GH8, 6JE6 and 21FJ crack and go to air after returning a retired set to service. None of these tubes were being touched, they just went to air while the set was off after I started using the set again.
I suppose Glass ages just like anything else, maybe after 50 or 60 years minor flaws become fatal flaws.
Reply With Quote
  #498  
Old 07-27-2012, 11:00 AM
kvflyer kvflyer is offline
VideoKarma Member
 
Join Date: Nov 2006
Location: Catonsville, MD, USA
Posts: 801
And I too have had tubes crack after lengthy power off. The CTC-9C that I have had a cracked audio output tube, I think, 6AQ5. Had a 7591 crack and give a really nice purple show as the air leaked in. Now THAT was an expensive tube...
Reply With Quote
  #499  
Old 07-27-2012, 02:40 PM
zenithfan1's Avatar
zenithfan1 zenithfan1 is offline
Mark
 
Join Date: Jan 2008
Location: Kenosha, Wisconsin
Posts: 4,142
I guess I've been lucky, I've never had a tube go to air. I've found a few in sets that I picked up but never while I've owned them. I better go knock on wood now. I just looked behind me and the CTC 11 that was dropped down the stairs is running in the living room. I use it every day.... I woke it up from a very long sleep.
__________________
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-939, ER-420, SM-B201
Motorola SK77W-2Z tube console
McIntosh MC2205, C26
Reply With Quote
  #500  
Old 07-28-2012, 12:11 AM
joemama99 joemama99 is offline
VideoKarma Member
 
Join Date: Jun 2007
Location: Sebring,Fl
Posts: 129
I knew you would get that one going,Mark.
Reply With Quote
Audiokarma
  #501  
Old 07-30-2012, 01:37 AM
colorfixer's Avatar
colorfixer colorfixer is offline
VideoKarma Member
 
Join Date: Aug 2005
Posts: 319
judging from the basket case 15g that RACS resurrected, I wouldn't think that this tube would be an issue since they would need to redo the neck of the tube to rebuild it in any event.
Reply With Quote
  #502  
Old 07-30-2012, 06:00 AM
tvcollector's Avatar
tvcollector tvcollector is offline
VideoKarma Member
 
Join Date: Sep 2010
Location: So. Florida
Posts: 1,556
Isn't there a place in France that still rebuilds picture tubes? if so, I'm sure the shipping alone would be outstanding..
Reply With Quote
  #503  
Old 07-30-2012, 11:41 AM
miniman82's Avatar
miniman82 miniman82 is offline
First Light: 1952-2011
 
Join Date: Jun 2009
Location: Great Mills, MD
Posts: 4,087
Yes, it's just a simple neck weld. The problem comes from the fact that if the planar dot plate and mask are heated at a different rate than the rest of the tube, the plate can crack or the mask can bend. This is the same issue as with the 15G, but it's worse because the prototype tubes have more thermal mass than a 15G does because its internal supports are heavier. This means even longer bake out times, and more cost. I've read notes from early books on the developmental tubes that state the face should be shielded during cooldown, to avoid cracking.
__________________
Evolution...
Reply With Quote
  #504  
Old 04-22-2013, 09:15 AM
miniman82's Avatar
miniman82 miniman82 is offline
First Light: 1952-2011
 
Join Date: Jun 2009
Location: Great Mills, MD
Posts: 4,087
Just a reminder to all convention goers, Steve will be talking about the proto set this year and I assume there will be a demo of it working for all to see. Should be an interesting speech, hope I can be there to see it.
__________________
Evolution...
Reply With Quote
  #505  
Old 04-22-2013, 02:36 PM
47'Plymouth 47'Plymouth is offline
VideoKarma Member
 
Join Date: Sep 2011
Location: Laurens,SC.29360
Posts: 233
Heyboer Transformers 616-842-5830.they could you one from scratch if you had all of the specs on the power tranformer to run the set..ask for Phil...tell him i sent you..he could make you the filter choke(s) also if the specs on them also... Jody
Reply With Quote
Audiokarma
  #506  
Old 04-22-2013, 11:48 PM
Mal Fuller Mal Fuller is offline
VideoKarma Member
 
Join Date: Jun 2011
Posts: 111
I also endorse Heybour Transformer. Here's what I have for contact information:
Reply With Quote
  #507  
Old 04-23-2013, 10:08 AM
miniman82's Avatar
miniman82 miniman82 is offline
First Light: 1952-2011
 
Join Date: Jun 2009
Location: Great Mills, MD
Posts: 4,087
What's all the hubbub about transformers?
__________________
Evolution...
Reply With Quote
  #508  
Old 04-24-2013, 12:57 PM
Steve McVoy's Avatar
Steve McVoy Steve McVoy is offline
VideoKarma Member
 
Join Date: Oct 2002
Location: Columbus, Ohio
Posts: 1,128
I think someone confused the comments about the power supply chassis being missing. The problem is not a missing power transformer - we don't even have the schematic for the power supply chassis.
Reply With Quote
  #509  
Old 04-24-2013, 05:23 PM
47'Plymouth 47'Plymouth is offline
VideoKarma Member
 
Join Date: Sep 2011
Location: Laurens,SC.29360
Posts: 233
Then make one my friend,
Steve,... they've designed me one for 1927'Colonial 31 AC highboy console radio, that the power supply and speaker was missing
when i bought her,..he 's came up with the power transformer, chokes and audio transformers from using my schematic that I've got,...sent a copy to Phil and the rest is history,now you said you've got no schematic of it....what about you're having the voltages requirements and currents i.e.(milliamps) of the tubes and other goodies reqired to operate the set...you could get close enough to build it within 20 % tolenece of operating the set...have sheet metal fabber make up the missing chassis....just and idea!
Jody
Reply With Quote
  #510  
Old 04-25-2013, 08:47 AM
Steve McVoy's Avatar
Steve McVoy Steve McVoy is offline
VideoKarma Member
 
Join Date: Oct 2002
Location: Columbus, Ohio
Posts: 1,128
We did make a supply some time ago. See the report on restoration of this chassis:

http://www.earlytelevision.org/rca_cpa_restoration.html

Designing a power supply isn't rocket science, and we used transformers we had pulled from junk chassis.

The problem, however, was that we don't have a schematic for either the main or power supply chassis, and don't have documentation of the supply voltages. We had to guess and experiment to come up with what we think are the correct voltages.
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 01:36 AM.



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