[QuadList] DPS TBC (Was NEC TBC)

[Don Norwood]

Ed:

I agree completely with Chris's comments.   If you have off-air recordings of broadcast video, then as long as the TBC will deal with the lack of burst, you may be OK.  The problem comes with tapes made from B&W non-broadcast cameras.   It was VERY common in the days of B&W EIAJ recordings to have cameras that did NOT produce RS-170 sync.  At the worst, many were random interlace.  The next step up was fixed interlace, but often without equalizing pulses and with non-conforming widths for sync and blanking.   

In modern-day equipment, just about everything that uses a composite video input expects to see burst present.  In doing quad transfers, there can be problems with B&W quad tapes due to the lack of burst, necessitating the addition of burst before the signal is usable.

Don 
  ----- Original Message ----- 
  From: COURYHOUSE at aol.com 

  oh......   I am going to  have to look ito this...

  In a message dated 7/12/2009 10:36:27 A.M. US Mountain Standard Time, Chill315 at aol.com writes:
    This brings up some more cans of worms.

    Is the sync on the tape NTSC EIA sync?  If not, the TBC may not recognize the Vertical interval and memory addressing will be an issue.  Plus if not interlaced, I have no idea what will happen.  This is experimental territory for me.

    Next, you have to make sure that the TBC will process Black and White signals.  A multiple of 3.58 is used in all TBC's to generate a write clock.  Usually 4X but also 3X.  If there is not a color burst, then the TBC has to generate a write clock.  Many times this is done with an oscillator that is referenced to the H sync frequency.  Make sure that the TBC can do this.

    Wish you luck with this one.

    Chris Hill
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