Re: [AV Media Matters] Answers to Some Technical Questions -WARNING - LONG A

[Jim Wheeler <Jimwheeler@aol.com>]

Ampex no longer makes the DCT.  In my opinion, the DCT was the best videotape
machine ever made.

Ampex still makes a data machine that uses the DCT tape transport.  It is the
DST.  Since it records data (not structured video), it cannot compress the
information and cannot use error concealment.  It has an incredible
three-level error correction system.  A "typical" used tape will have a raw
(off tape) error rate of one error for every 10,000 bits on a DST.  After
correction, it is around one error for every 100,000,000,000,000.

I ran several DST tapes several thousand passes and the error rate never
changed except at the points where the tape was threaded around the scanner
and unthreaded.  That's why I insist on never stopping an important
videotape
in an area with a recording.

Jim Wheeler