Videokarma.org

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

Notices

We appreciate your help

in keeping this site going.
Reply
 
Thread Tools Display Modes
  #1  
Old 08-17-2008, 03:01 AM
leadlike's Avatar
leadlike leadlike is offline
VideoKarma Member
 
Join Date: Apr 2008
Location: Lancaster, Pa
Posts: 956
I've got a CRT tester! Questions too!!

Okay, I finally got myself a CRT tester-a sencore cr128. Now I'm pretty sure this is a bottom of the barrel model, so I don't plan to do any rejuvination with this...I just want a basic emissions tester for now. It came with a thick(ish) book, so I thought it was all there, but it turns out it is only the operating manual. I'd like to know if there is a source for tube charts. Another alternative is that I will be getting a copy of a GE crt manual which will have all the tube data I need. But how to I apply that to the tester? Specifically, I'm most concerned with the G2 switch which has three settings: lo 1, lo2, and hi.

From the manual: "G-2: this switch is used to select the proper B plus voltage to the G-2 electrode. Some tubes are designed to operate with the first anode potential of only 50 volts. Some later tubes have a G-2 voltage as low as 30v. If these tubes are tested in the lo-1 position, the emission indication will be above normal. An lo-1 or lo-2 G-2 type tube can be damaged if it is operated with the switch in the hi position. This is common to all modern crt testers and is set from the set-up chart."

So, pouring over the few tube data sheets that I have here, most give a G2 voltage of 300v. So I guess that would be "hi"? I just don't want to toast a crt with this thing...
Reply With Quote
  #2  
Old 08-17-2008, 03:35 AM
leadlike's Avatar
leadlike leadlike is offline
VideoKarma Member
 
Join Date: Apr 2008
Location: Lancaster, Pa
Posts: 956
Okay, bit of an update:

just opened it up, and found a diconnected electrolytic. Never a good sign. But I tested some possible trouble areas, and the only failed component I found was this electrolytic cap. Little wonder, as it is only a 150v unit and it is the input unit that takes all of the crap coming off of the AC lines.

I'm actually surprised to find that anyone was in here; as the tester looks (and even smells) brand new. Hopefully a cap swap is all it needs. I guess I shouldn't be surprised, though-this came from a flea market and it only cost a couple bucks. Just all part of the fun of getting what ya pay for.
Reply With Quote
  #3  
Old 08-17-2008, 09:34 AM
andy andy is offline
VideoKarma Member
 
Join Date: Jul 2002
Posts: 4,004
...

Last edited by andy; 12-07-2021 at 11:02 AM.
Reply With Quote
  #4  
Old 08-18-2008, 01:48 AM
eberts eberts is offline
VideoKarma Member
 
Join Date: Mar 2008
Posts: 139
http://www.sencore.com/support/index.php?id=46
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 11:10 AM.



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