[GreenKeys] KSR-33 chattering issue - both local and line - shouldn't be keyboard

[teletypeparts at comcast.net]

PJ, 
  
The 33 in your video is an ASR.  
  
Swapping out the kybd is probably not the first step you should have taken but oh well.... 
  
The extra power supply in the UCC-6 is the PS for the tape reader.  
  
Check the fuses in the UCC-6, one controls the local loop current.  
  
Try to make the 33 type in Local first.  Let Line mode wait till later.  
  
If you jumper Molex # 7, (kybd Molex) pins 10 and 11, this will eliminate the kybd loop.  
You can remove the Molex and use a paper clip opened up instead of the special plug in the pic. 
  
Check the SMD card in the UCC-6 for a loose top resistor.  The big one on the only circuit card that slides out vertically.  
  
Lots of visual checks on a 33 can usually find the trouble. 
  
Best regards, 
  
Wayne 
KB1FDW 
  
  
----- Original Message -----

From: "PJ Bennett" <pj at pjbennett.com> 
To: greenkeys at mailman.qth.net 
Sent: Saturday, August 22, 2015 11:55:41 AM 
Subject: [GreenKeys] KSR-33 chattering issue - both local and line -        shouldn't be keyboard 



I have two teletypes, an ASR-33 which is working fine and a KSR-33 which is chattering in both local and line mode.  I have switched out the keyboard with the other unit and no change.  I tried adjusting the H bar, no luck.  The KSR-33 had an extra, homemade power supply included in the UCC, but I think this was only to provide loop power.  I took it out and I think the UCC is back to normal. 

  

I’ve read as much as I could find on the various websites and forums, and several point towards the keyboard, but I’m pretty sure this isn’t the problem since I tried a working (from ASR, which I think is compatible) keyboard.  The problem is just like the one in this video:  https://www.youtube.com/watch?v=ODdcUSgReYM   The KSR chatters and the distributor advances one rotation with every key press.  Exactly the same in both line and local mode. 

  

Just looking for suggestions on other things to check.  My next step is to trace out the wiring for the UCC and make sure the previous owner who added the power supply didn’t make any other changes (doesn’t look like it though). 

  

Thanks for any suggestions you may have. 

  

PJ 

  

_____________________________________ 

PJ Bennett, BSEE 

918.704.7055 | pj at pjbennett.com | pjbennett.com 



  

______________________________________________________________ 
GreenKeys mailing list 
Home: http://mailman.qth.net/mailman/listinfo/greenkeys 
Help: http://mailman.qth.net/mmfaq.htm 
Post: mailto:GreenKeys at mailman.qth.net 

2002-to-present greenkeys archive: http://mailman.qth.net/pipermail/greenkeys/ 
1998-to-2001 greenkeys archive: http://mailman.qth.net/archive/greenkeys/greenkeys.html 
Randy Guttery's 2001-to-2009 GreenKeys Search Tool: http://comcents.com/tty/greenkeyssearch.html 

This list hosted by: http://www.qsl.net 
Please help support this email list: http://www.qsl.net/donate.html 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/greenkeys/attachments/20150822/a84b5231/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Kybd Blind or bypass.JPG
Type: image/jpeg
Size: 379205 bytes
Desc: not available
URL: <http://mailman.qth.net/pipermail/greenkeys/attachments/20150822/a84b5231/attachment-0001.jpe>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image002.jpg
Type: image/jpeg
Size: 2863 bytes
Desc: not available
URL: <http://mailman.qth.net/pipermail/greenkeys/attachments/20150822/a84b5231/attachment-0001.jpg>