Videokarma.org

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

Notices

We appreciate your help

in keeping this site going.
Reply
 
Thread Tools Display Modes
  #1  
Old Yesterday, 12:03 PM
Aperna1985 Aperna1985 is offline
VideoKarma Member
 
Join Date: Feb 2018
Posts: 184
B&K 465 weak voltage

I've had my B&K 465 for about 8 years now. It's actually been a really good tube tester and I've used it to rejuvenate quite a few tubes. I noticed that anytime G2 voltage is 50 volts on a tube it tests very bad. So today on a hunch I used the tube pin out and checked the G2 voltage what should be 50 volts was only 20. I think the original components are starting to fail. I attached the schematic below. Judging from the drawing other than the Transformer they seem to be what makes up the main power supply for the entire tester. Am I right in thinking that if I replace the two 5 microfarad capacitors I should be able to bring this thing back ? To me they seem like they're the main filters and maybe they're getting weak? Or am I more likely to have to go after the 4 Diodes just before them.
Attached Files
File Type: pdf bandk465schematic.pdf (908.5 KB, 2 views)
Reply With Quote
  #2  
Old Yesterday, 06:37 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: 7,772
There's not that much to the unit, so while you're replacing the caps on general principles, it would be quick and easy to check the 100 ohm and 470k ohm resistors. I would feel dumb if I didn't take the opportunity.

Also, C-3 and C-4 (50 mfd) and R9 and R10.
__________________
www.bretl.com
Old TV literature, New York World's Fair, and other miscellany

Last edited by old_tv_nut; Yesterday at 06:42 PM.
Reply With Quote
Reply



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 03:13 PM.



Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2026, Jelsoft Enterprises Ltd.
©Copyright 2012 VideoKarma.org, All rights reserved.