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<DIV>Setting video levels is an interesting problem. What is the
philosophy that one should follow. At the production facilities I worked
at, we took the view that the video operator did his job correctly. That
was the heart of the question. We therefore had the following
procedure. </DIV>
<DIV> </DIV>
<DIV>Set the Proc Amp to Unity. Then use the Demod Level out to set the
video out of the machine.</DIV>
<DIV> </DIV>
<DIV>To do this it was necessary to do the following. </DIV>
<DIV> </DIV>
<DIV>Set unity levels in the proc amp. I used a scope with the invert and
add function to null out the levels at the highest gain possible. That way
it was as close as possible to perfect.</DIV>
<DIV> </DIV>
<DIV>The book has the alignment procedure. Here are the following pots
numbers and what they do.</DIV>
<DIV> </DIV>
<DIV>R-5 on the test point panel sets burst level.</DIV>
<DIV> </DIV>
<DIV>R-6 on the test point panel sets video level.</DIV>
<DIV> </DIV>
<DIV>R-9 on the test point panel sets the set-up level.</DIV>
<DIV> </DIV>
<DIV>R-39 Board 17 sets the blanking clamp level to the same as input.</DIV>
<DIV> </DIV>
<DIV>R-51 Board 13 sets the sync level.</DIV>
<DIV> </DIV>
<DIV>Once we did this, we found that the quality of the video shot up. We
were able to get more generations. The reason being that we did not make
slight changes to the video quality each pass. Miss-set the black level by
a couple of IRE's on the bars and over a few passes, you either wash it out or
darken it. Also it was the intention to keep the dynamic range at the
optimal point for each piece of the chain. </DIV>
<DIV> </DIV>
<DIV>The thing we found is that we rarely had to take the proc amp out of
unity. The times we did this was usually when we got a tape from a
station. They seemed to never have a set of best practices. It was
just throw up a tape and push buttons. Some even would record tapes
without bars and send them to us. Try to make a silk purse out a sows ear
on those situations.</DIV>
<DIV> </DIV>
<DIV>Chris Hill</DIV>
<DIV>WA8IGN</DIV></FONT></BODY></HTML>