MII with built in TBC

[88charlie]

I’m about to start a large analogue video conversion project and have been trying to source a working TBC.

Today I received a tip of a “cache” of various Beta and MII equipment from a discontinued local TV-station. The owner is willing to loan/give me some of it in return for assistance with capturing his own collection of MII tapes.

The only info I have so far is that the equipment consists of Panasonic professional/large units from, I guess, the late nineties.

Generally speaking, would typical studio MII machines have the possibility to use the built in TBC in a pass through mode?

This would be very practical to know before I dive in to moving and testing hundreds of kilos of studio equipment.

My own needs are mostly VHS and Hi8 related.

[lordsmurf]

Q: Use the built in TBC in a pass through mode?
A: No.

You need an actual frame TBC created for consumer sources like VHS and Hi8.

[88charlie]

Q: Use the built in TBC in a pass through mode?
A: No.

You need an actual frame TBC created for consumer sources like VHS and Hi8.

Ok. Thanks for the reply.

So all the MII hardware is basically useless for me in a VHS/Hi8 context?

What about scalers/switches and mixing tables? The cache includes all of that as well.

I have another source which can supply a Kramer VP-725DS

https://k.kramerav.com/downloads/pdf/product/1/VP-725DS.pdf

Says built in TBC but no details.

[Cornucopia]

To help clarify:

M/MII are professional component formats just as BetaCam/SP are pro component formats.

SVHS is semi-pro S-video(aka YC)/composite format just as EDBeta is semi-pro s-video/composite format.

VHS is consumer composite format just as Betamax is consumer composite format.

For S-video formats, it is fairly easy to incorporate composite formats, so almost ALL machines are backward compatible with consumer versions. Tape speeds, writing strategy, bandwidth basically the same.

For component formats, backwards compatibility is a lucky afterthought, as there is little that is common (the shell, and the tape size of 1/2"). Tape speeds, writing strategy, bandwidth, magnetic properties all different.
SOME models are backwards compatible, some (many? most?) are not.

This was also true of later digital decks like DigiBeta - some supported analog playback, most did not. Some supported intermediate digital formats (BetaSX, IMX), some did not. You must always check the manual to see which ones it supports.
Almost ALWAYS, that compatibility was playback-only and did not extend to recording (exceptions with the S-Video decks).

**********************************

Some of those pro decks include an internal line-tbc, but AFAIK, NONE of them included onboard full-frame tbc. Pro decks had less cause (than consumer decks) to need them as they were much better at the stability of their timebase, but it was still best practice to run the signal through one anyway.


Scott Warren

[88charlie]

To help clarify:

M/MII are professional component formats just as BetaCam/SP are pro component formats.

SVHS is semi-pro S-video(aka YC)/composite format just as EDBeta is semi-pro s-video/composite format.

VHS is consumer composite format just as Betamax is consumer composite format.

For S-video formats, it is fairly easy to incorporate composite formats, so almost ALL machines are backward compatible with consumer versions. Tape speeds, writing strategy, bandwidth basically the same.

For component formats, backwards compatibility is a lucky afterthought, as there is little that is common (the shell, and the tape size of 1/2"). Tape speeds, writing strategy, bandwidth, magnetic properties all different.
SOME models are backwards compatible, some (many? most?) are not.

This was also true of later digital decks like DigiBeta - some supported analog playback, most did not. Some supported intermediate digital formats (BetaSX, IMX), some did not. You must always check the manual to see which ones it supports.
Almost ALWAYS, that compatibility was playback-only and did not extend to recording (exceptions with the S-Video decks).

**********************************

Some of those pro decks include an internal line-tbc, but AFAIK, NONE of them included onboard full-frame tbc. Pro decks had less cause (than consumer decks) to need them as they were much better at the stability of their timebase, but it was still best practice to run the signal through one anyway.


Scott Warren

I sort of new all that already, but I have been caught up in a (fake?) memory of a post or something where a pro VCR was promoted as allowing its built in TBC for pass through usage.

So all this MII hardware won’t help me at all then.

My only hope then would be that there’s some dedicated VHS/SVHS/Hi8 equipment in there somewhere and/or maybe a standalone TBC.

What about the Kramer switch i linked. Would that do any good and what type of TBC might it actually have?

[dellsam34]

If you start with a decent S-VHS deck with line TBC/DNR for VHS tapes and a Hi8/D8 camcorder with built in line TBC/DNR and always use S-Video cables, 80-90% of the problems are eliminated at the source, Then it's just a matter of baby sitting the signal, If you have no problems leave it alone, if there is an artifact address it accordingly by either adding an external frame TBC, a DVD recorder inline, one of the mixing consoles you have, the Kramer you posted about or even try the MII deck in the workflow, depends on what artifact you have. Keep in mind an external TBC is not going to improve picture quality it just fixes frames errors, if you have none keep it out.

[88charlie]

Thanks for all the advice. I’ll report back when i get an overview of all the equipmen

[lordsmurf]

As always
- line TBC fixes the visual quality (stuff you see)
- frame TBC fixes the signal quality (stuff you can't see)

You need both.

Ideal is an actual frame sync TBC (not mere frame sync), aka frame TBC (misnomer). But there are budget options, shortcuts, that can sort-of work. But those have fail rates, side effects on both image and signal quality, and is heavily dependent on source tape quality AND deck used. Those are what I refer to as "TBC(ish)".

Hooking up a VCR to TV was easy, idiot proof, you were sheltered from problems.
Converting VHS/etc to digital, diapers come off, you see the real video world as it exists. It ain't pretty.

(And regardless of what you may see from some Youtube numbnuts with misleading videos.)

[88charlie]

I think I found the post that got me chasing studio VCR’s for their TBC.

http://www.dvxuser.com/V6/showthread.php?366164-Digitizing-VHS-tapes/page2

[oln]

Hmm, I've tried that once with a betacam deck. It sort of worked, it seemed the TBC buffered full frames or at least a full field, though it only worked with the pro SVHS VCR that had sync input to lock the servo to the TBC sync signal. Otherwise the picture would just roll. The horizontal sync detection also didn't seem to work very well as the image was a bit jittery horizontally but I don't know if that was inherent to the TBC or if could have been due to the betacam having aging components or something else as I didn't have any betacam tapes to test the internal playback with.