Posted by Gary Eickmeier on 12/26/59 11:32

Richard Crowley wrote:

> "Gary Eickmeier" wrote ...
>
>> Thanks Richard. The diagram shows that the audio is the first part of
>> the track picked up, not the last. The subcode is the last. But I
>> son't see how any part of that scan could be missed by a new head
>> drum, especially if you have auto alignment of the scan.
>
>
> The first part (or the last part) of the scan can be flaky
> if the tape wrap around the head drum is not perfect.
> The auto-tracking servo averages the whole diagonal
> swipe to try to keep everything in sync.
>
> Find a heli-scan machine that you can take the cover off
> (or a reel-to-reel machine) and tweak the tape path
> slightly to see what happens to different parts of the
> picture (and sound).
>
> Those of us who grew up with heli-scan videotape tend
> to be continuously amazed that it works so well. This kind
> of glitching is notable only because modern technology has
> made it so rare.
>
> As for what happens when you replace the head drum
> (or do any work to the tape path), whether it will track
> previous tapes depends on whether the tapes were written
> by a properly-aligned machine (or not). If your re-built
> machine has good interchange with other new camcorders,
> but won't play back its old tapes, it means that it was already
> out of alignment when the old tapes were written. This is not
> all that uncommon. It is almost guaranteed with the long-
> playing (slow) speed modes. You're lucky if your own
> machine will interchange LP tapes.
>
> You have the choice to have them align the transport to
> your old tapes, but then it won't interchange with anything
> else, or have them align it to industry standards and lose the
> ability to read out-of-spec tapes.

I thought I was clear about that - the new alignment is what is out of
kilter, not the old. We have four Sony cameras in our studio. They all
would play each other's tapes just fine, even at LP speed. No problem.
Now my camera is the odd man out. It won't play my old tapes or the
other cameras' tapes perfectly. On our last job, we shot my camera and
one other VX2000, at LP speed. The three other cameras will not play my
tape, but my camera will. Didn't test my camera playing the other tape,
but I would expect it wouldn't play.

I have found all new sonys will play each other's tapes just fine. So it
is something they did wrong in aligning it. If the factory can align
these things, they should be able to.

Thanks for your comments,

Gary Eickmeier

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