the signal can lock

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the signal can lock

Post by wille » Wed Oct 06, 2004 1:57 pm

dear sir ,
Kindly advise the follows
we having Adc 200 and intend to view of video wave form (standard signal of TV)
Our set up as follows :

ext. channel connected Video out and one of RGB signal to Channel A,and set auto trigger to ext ! seen like the trigger syncronise
we cannot hold the signal from channel A ,which intend make Measurement voltage on certain line (unstable ) ,please advise Best way to make it hold ?

Thank , your advice will much appreciated



Post by Sarah » Mon Oct 11, 2004 9:45 am


Thank you for your post.

I suggest triggering off the input, ie put the signal on channel A and then set the trigger for channel A.

You then need to set the trigger threshold for a value that is only reached at one point in the cycle. The difficulty with video signals is that when the trigger is set in the middle ranges there are a number of points for it to trigger off on the cycle and hence it appears to 'jump' a bit. If you set the trigger for just below the maximum point reached, or likewise just above the minimum point, this should help the trace to stay fixed on the screen.

Hope this helps.

Best Regards

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