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Re: D1 Control Track/RF Problems



Although it is tempting to replace the lower drum when this problem comes up,
you may want to check further before going this route.  Unless Sony has come
out with a new and improved scanner, you'd be setting yourself up for an
expensive repair which might only remain in spec a little while (our machines
looked good for the first few months of operation, then...)

<< My other question is how and where were the "software"changes made to make
 the machine behave better?
 
 Overall I agree that these machine seem to be way to sensitive to the real
 world use. A tape that has been black encoded should have errors less than
1.
 It is nice to record information with out compression but if you are always
 using error correction to make up the missing information are you really any
 better off? >>


The software changes referred to were to allow the machine to work with
slightly increased tensions around the scanner, greatly improving the control
track output without the machine tripping off into high tape tension error
mode.  (The sensors are extremely sensitive, and when they trip, you can't
get the machine to eject a tape!)  The mods were done by Sony Service in
Teaneck, N.J., and quite frankly, I am not sure which PROMs were
replaced/reprogrammed, or what else was done.  We also did the upgrade which
allows the machine to make full use of the new Sony "A" stock.  When this did
not entirely fix the CTL track problems, we adjusted back to the slightly
higher scanner tensions through the software set-up in the service manual.

No compression is better than having it, all other things being equal,
because no present-day compression algorithms and hardware are capable of
dealing equally well with every possible type of image that might come up.
 But only as long as the error rate remains below the "digital cliff," that
point where the errors get so bad that the correction/concealment can no
longer cope.  On the other hand, a non-compressed VTR that can't even play
back its own recordings without going over the "digital cliff" on a frequent
basis deserves to be tossed over a real cliff, if you want my humble opinion.

Christopher Bacon
DuArt Video