Thread: TV repair books
View Single Post
  #8  
Old 09-20-2009, 03:04 PM
DaveWM DaveWM is offline
VideoKarma Member
 
Join Date: Feb 2009
Location: Orlando FL
Posts: 5,607
Quote:
Originally Posted by cbenham View Post
I have a set that 'breathes'--an RCA 9T-256. I also have a 9T-246 that DOES NOT breathe. ??? I can't see any ripple on the B+ lines anywhere in the sweeps or the power supply. The only difference between these two sets is that the 256 has a relay with a wired remote switch to 'expand' the size of the image.
It works fine but the picture breathes in both modes. Could this be caused by the power transformer radiating magnetically into the yoke? I tried placing a steel panel between the yoke and the xfmr but this didn't do anything to reduce the breathing. Any help is greatly appriciated. Thanks, Cliff
if the freq is slow, then like mine it may be a beat freq of the AC line and the vert sweep. If that is the case you could do like I did and see if running the vert tubes on DC filaments makes it go away, or better yet, just make sure you have a good ground return on the filaments (which was the cause for my breathing issues).
Reply With Quote