Videokarma.org

Go Back   Videokarma.org TV - Video - Vintage Television & Radio Forums > Diagnostic & Test Equipment

We appreciate your help

in keeping this site going.
Reply
 
Thread Tools Display Modes
  #1  
Old 02-10-2017, 10:08 PM
TUD1's Avatar
TUD1 TUD1 is offline
TheUniversalDave1
 
Join Date: Jan 2014
Location: Birmingham, AL
Posts: 1,611
B&K 465 acting strange

I really love my trusty B&K 465, but when I went to use it tonight on a tube, I noticed that when I set the switch to emmision, whichever color I set the tester to, glowed blue inside the tube. I made sure I had the voltages set to the book. 40 volts on G1, about 275 on G2. I could also feel a very slight AC voltage on the tester itself at all times. What's going on with my beloved 465?
Attached Images
File Type: jpg IMG_20170210_215936.jpg (66.1 KB, 24 views)
__________________
"If you wish to make an apple pie from scratch, you must first invent the universe." -Carl Sagan
Reply With Quote
  #2  
Old 02-10-2017, 10:11 PM
Jon A.'s Avatar
Jon A. Jon A. is offline
Don't mess with Esther.
 
Join Date: Jun 2013
Location: Canada
Posts: 4,267
It's not the tester, looks like you have a gassy CRT.
Reply With Quote
  #3  
Old 02-10-2017, 10:17 PM
TUD1's Avatar
TUD1 TUD1 is offline
TheUniversalDave1
 
Join Date: Jan 2014
Location: Birmingham, AL
Posts: 1,611
Both RCA Hi Lite tubes that I tried did that. Are they both junk? They both looked fine before I took them out of sets.
__________________
"If you wish to make an apple pie from scratch, you must first invent the universe." -Carl Sagan
Reply With Quote
  #4  
Old 02-10-2017, 10:22 PM
Jon A.'s Avatar
Jon A. Jon A. is offline
Don't mess with Esther.
 
Join Date: Jun 2013
Location: Canada
Posts: 4,267
No idea, but my Heathkit GR-370 had a RCA Hi-Lite 25BCP22 that was the weakest CRT I've tested yet. No blue glow though.
Reply With Quote
  #5  
Old 02-10-2017, 10:42 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
When I test a gassy tube on my B&K 466 setting the cutoff knob (which states to adjust meter up by 2 divisions) will have an all-or-nothing response from the needle and there will be blue or purple glow in the neck...The worse the tube the bigger the glow.
__________________
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
Audiokarma
  #6  
Old 02-10-2017, 10:59 PM
TUD1's Avatar
TUD1 TUD1 is offline
TheUniversalDave1
 
Join Date: Jan 2014
Location: Birmingham, AL
Posts: 1,611
These Hi Lite tubes (that I JUST de cataracted) both test perfectly fine on all my testers. Even on the 465, there were no anomalies when setting cutoff, and they both tested between 80 and 90 percent.
__________________
"If you wish to make an apple pie from scratch, you must first invent the universe." -Carl Sagan
Reply With Quote
  #7  
Old 02-10-2017, 11:08 PM
MadMan's Avatar
MadMan MadMan is offline
The Resident Brony
 
Join Date: Oct 2016
Location: Chicago
Posts: 1,217
I'm pretty sure that means the crt is full of air. Why not just test a known-good tube? You know... like one that's actually inside of a working tv that you have watched recently? I know you have at least one -_-
Reply With Quote
  #8  
Old 02-10-2017, 11:09 PM
Jon A.'s Avatar
Jon A. Jon A. is offline
Don't mess with Esther.
 
Join Date: Jun 2013
Location: Canada
Posts: 4,267
My guess is that emissions will drop quickly under regular use, or suddenly drop to nothing when the filaments open.
Quote:
Originally Posted by MadMan View Post
I'm pretty sure that means the crt is full of air. Why not just test a known-good tube? You know... like one that's actually inside of a working tv that you have watched recently? I know you have at least one -_-
Yeah, what he said.

If a lot of heat was used for cataract removal, it may have gotten to the guns and compromised the seal at the pins.

Last edited by Jon A.; 02-10-2017 at 11:16 PM.
Reply With Quote
  #9  
Old 02-11-2017, 06:59 AM
SwizzyMan's Avatar
SwizzyMan SwizzyMan is offline
Restoring an admiral c322
 
Join Date: Apr 2015
Location: Side Lake Mn
Posts: 886
I could've sworn gassy tubes glow a bright purple, not blue due to the discharge of ionized oxygen. I have some tubes that glow blue on the neck glass due to electron bombardment. Is the tester responsive at all?
__________________

Admiral C322C2 Regent (Restoring)
RCA CTC-7 Pensbury (Restored)
RCA CTC-5 Westcott (Restored)
CRA CTC--4 Director 21 (Restoring)
Reply With Quote
  #10  
Old 02-11-2017, 08:59 AM
andy andy is offline
VideoKarma Member
 
Join Date: Jul 2002
Posts: 4,004
///

Last edited by andy; 11-18-2021 at 05:09 PM.
Reply With Quote
Audiokarma
  #11  
Old 02-11-2017, 09:34 AM
TUD1's Avatar
TUD1 TUD1 is offline
TheUniversalDave1
 
Join Date: Jan 2014
Location: Birmingham, AL
Posts: 1,611
I hooked the tube up to the chassis out of the cabinet, and the tube works just fine. I also tested a Magnavox 25VCXP22, and it did not have any blue glow.
Attached Images
File Type: jpg image.jpg (55.4 KB, 11 views)
__________________
"If you wish to make an apple pie from scratch, you must first invent the universe." -Carl Sagan

Last edited by TUD1; 02-11-2017 at 09:46 AM.
Reply With Quote
  #12  
Old 02-11-2017, 11:08 AM
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
If you've got raster your tube is not gassy (or at least not very gassy). When a CRT is full of gas you won't get a raster and the HV will probably arc to the gun and the HV system will cry bloody murder.
__________________
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
  #13  
Old 02-11-2017, 06:21 PM
Jon A.'s Avatar
Jon A. Jon A. is offline
Don't mess with Esther.
 
Join Date: Jun 2013
Location: Canada
Posts: 4,267
Quote:
Originally Posted by TUD1 View Post
I hooked the tube up to the chassis out of the cabinet, and the tube works just fine. I also tested a Magnavox 25VCXP22, and it did not have any blue glow.
Man, I'd like to get hold of a couple of strong 25VCXP22s, or 25VBEP22s, I think only the mounting hardware is different. Two of my best sets use them.
Quote:
Originally Posted by Electronic M View Post
When a CRT is full of gas you won't get a raster and the HV will probably arc to the gun and the HV system will cry bloody murder.
Probably the same sound I heard when I fired up my Heathkit GR-2000 with the 2nd anode cap accidentally left off. It was deteriorating and wouldn't hold well anyway so I replaced it with a screw-set cap from an old RCA.

Last edited by Jon A.; 02-11-2017 at 06:26 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 12:43 PM.



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