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  #46  
Old 12-23-2016, 02:11 PM
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Quote:
Originally Posted by old_coot88 View Post
Why not use a battery? 9V would probably run it OK, and drain would be minimal. Give it an on/off switch.

(Hum bars are the horizontal dark shadings in the raster due to 60 or 120 Hz ripple (hum).
I actually have a 12V battery in my pocket for that purpose. I figured I'd start there with my power supplies as it would be the "cleanest" supply.
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  #47  
Old 12-23-2016, 05:02 PM
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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.
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  #48  
Old 12-23-2016, 05:03 PM
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Originally Posted by vts1134 View Post
I actually have a 12V battery in my pocket for that purpose. I figured I'd start there with my power supplies as it would be the "cleanest" supply.
Good idea.
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  #49  
Old 12-23-2016, 07:30 PM
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It was the power supply. Using a 12v battery eliminated the vertical bars. I have two other video problems that will need to be addressed, but I need to ascertain whether the problems come from the inverter, or are inherent to the set. I'll report back after some experimentation.
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  #50  
Old 12-29-2016, 09:31 AM
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I've had precious little time to spend at my bench, but I did manage to sneak this 10 second video in on where I am. There is some crazy interference happening right now that I wanted to show you guys. I hope some one has seen this before and can point me in a direction. I am using shielded video cable (I thought that might be the issue). Any one ever seen something like this? https://youtu.be/zgcznUOokvw

P.S. I will try to get some time today to fire up the B&K 1077 and see if the issue persists when using it to inject video instead of the video circuit we made.
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  #51  
Old 02-16-2017, 07:32 PM
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I'm continuing this topic in a thread about the restoration of the television in which I will be using this amplifier. Here's a link to that thread http://videokarma.org/showthread.php?t=268361
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