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Re: D1 control track problems

Dear Craig,

We've been battling control track dropout problems identical to those you
reported with our pair of DVR 2100s for about a year now, along with the good
folks from Sony.  It's one of those situations where so much is going on, you
can't seem to get a handle on it, and nobody seems to be able to give you a
straight answer.

First off, whose stock are you using?  We find quite a bit (no pun intended)
of variation from manufacturer to manufacturer, and from one batch to the
next.  Sony's newest stock seems to be an improvement over the previous
version, but it still isn't a 100% guaranteed answer.

Environmental conditions make a very big difference to these machines--both
where the machine is operated and where the tape is stored.  Again, the new
tape stock doesn't seem as fussy as the old stuff was, but we still find that
if our temperature/humidity control system has gotten out of spec, the first
place we find out about it is when the D-1s start acting up.

Finally, the tape tension appears to be a major difficulty in the DVR 2xxx
series machines.  By design, the tension is very low, so far down that the
tape sometimes doesn't make good contact with the control track head, which
is built into the scanner at the bottom of the tape guide.  My theory is that
the problem could be that as the head wears (or as the glue that holds it to
the scanner shrinks), the head-to-tape contact gets too low to work reliably.
 This is why these machines seem okay when you take them out of the box, but
after several months' to a years' worth of use, they start conking out.

After getting disgusted with the lack of progress on this thing, we decided
to increase the tape tensions slightly, which seems to pull the tape back
into the control track head and thereby fix the problem.  This is quite a
painful process, as you have to enter coefficients in hex into an engineering
menu, then reboot the machine to see what difference it made--if any.  Of
course the machine still has to be in interchange when you finish, and if you
go too far, the machine starts giving you all kinds of error messages when
nothing is wrong because it thinks the tape is jammed!  A couple of software
revisions have been made to make the machines a little less sensitive to
this, so it might pay to check with Sony and see where you are.

DCT was (and still is) a better way to go!

Hope this helps.

Christopher Bacon
DuArt Film & Video