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  1. Member
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    For decks that you believe to be in good shape but want to have a reference tape to periodically re-capture and double check (or look for drift/degradation) how would you go about creating a reference? I have struggled with this for some time; when I capture audio this is standard operating procedure and a reference tape is easy to source or with the right equipment a serviceable one can be created. For SVHS and VHS I have not been so sure.

    A couple of years ago I found a decent DAC with S-Video input and tried to feed it the sharpest digital content I could and it seemed OK for grins but admittedly it felt janky. Is there such a thing as a VHS or SVHS reference or calibration tape? Or, a decent methodology in 2021 for creating one?

    I have a few AG-1980Ps serviced in the last 2-3 years, lightly used, that I could use to create a reference if I could settle on an input that I have no misgivings about. Curious for ideas people have on quick-and-dirty options that work for you.
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  2. Member Cornucopia's Avatar
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    EE supply channels, particularly for Broadcast engineers, used to have reference calibration tapes (usually bars & tone, and other test patterns w/ conformance levels etc, plus a sample color-tone image and possibly a stress-test sequence). Markertek, perhaps? But that was 25+ years ago, so don't know what is available anymore.

    You'd need to make sure that any "calibration" tape was created on a machine that was already itself calibrated, or it would skew everything following.

    Good luck.

    Scott
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  3. Member dellsam34's Avatar
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    For just making a tape to align other decks' tape transport you can record color bars using a well known factory calibrated VCR (never been tempered with or re-aligned by a service center), But for other tests such as RF level, wave form and stuff like that you would need special video equipement for that, You can't just hookup a media player with video files and record to VHS tape, no it doesn't work that way.
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  4. Member Cornucopia's Avatar
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    Depends on what kind of calibration we are talking about here.

    Setting levels in a proc amp (hopefully with the assistance of vectorscope/waveform monitor), no problem.
    Adjusting tracking, iffy but partially doable.
    Adjusting RF, interchange, as dellsam34 mentioned, no can do. That needs dedicated vcr test bench equipment. Much more involved. This is, luckily however, is something that should only need be done every ~6mo or year. Or as needed after major shipping/environmental change.


    Scott
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  5. Member
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    IIRC, the Sony techs told me they used their Betamax calibration tapes for a set number of times because of wear on the tapes.
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