View Single Post
  #47  
Old 12-23-2016, 05:02 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: 7,184
Quote:
Originally Posted by vts1134 View Post
What do you mean by this?
As oldcoot88 said, hum bars are those dark horizontal bars that run upward or downward in your video. I now notice that they seem to change direction during the time recognizable video is on the screen. This should not happen if the video vertical rate is stable and the hum bars come from the power supply (AC line). What is your video source? Could it be accelerating up to speed? It just seems weird.

You also have white retrace lines, which have to do with CRT vertical retrace blanking (or lack thereof) and maybe copy protection on the video source.

So, again, the thing to do is to set the video level correctly to get a stable picture, and then chase the interference issues.
__________________
www.bretl.com
Old TV literature, New York World's Fair, and other miscellany
Reply With Quote