I just stumbled on the fact that every time I hit the jog button to stop the tape to check if ltc and vitc match I noticed the TCR said F2 until the last tape I checked which consistently stopped on F1. Hmmmmmm When I say consistently I mean like 7 times in a row on multiple tapes all stopping on F2 until the last tape which always stopped on F1. I figured there might be a system relationship that no matter when you hit the jog button to stop the tape the tape transport circuitry might buffer the button push and issue the jog/pause command relative to some internal cycle that would somehow be related to or consistent with the CTL pulse. Hence my supposition that perhaps the fact that one tape always stopped on F1 unlike the other might indicate a ctrl track phase difference. I can remember adjusting the CTL head on 3/4 inch machines and you could definitely max tracking in two positions which could lead to a framing servo error and required CMX and others to modify the machines to analyze ctrl track phase relative to time code sync word and invert the phase if an error persisted for 4 times in a row IIRC. Now I'm wondering if there could be a similar error on one of the dub house betasps. I guess what I should check is the position of the time code sync word relative to house sync. Maybe I'll do that next batch of dubs if I see the same anomaly, but the way those decks tend to reclock/resync time code I'm not sure if the drift still shows up like with asynchronous code. I bet it does on the LTC out because I doubt that is regenerated like the RS-422 code is, another Hmmmmmm. And yes betasp is long in the tooth but a weekly deliver requirement of several copies to the cable network we are delivering to. I assume the network doesn't want to spend any money updating their infrastructure to rid themselves of betasp.
--- In Avid-L2@yahoogroups.com, Dennis Degan <DennyD1@...> wrote:
>
>
> On Dec 27, 2010, at 8:34 PM, John Moore wrote:
>
> > Today I noticed every time I hit the jog button to stop play the
> deck always parked on a Field 2 according to the time code reader on
> the deck. I figured that's just the way the ballistics of the machine
> worked until the last tape I checked always stopped on Field 1. This
> got me thinking there may be a relationship between ctrl track phase
> and where the machine parks, much like the issues we use to deal with
> in the 3/4 inch days when some decks didn't have framing servos.
>
> I offer:
>
> I have some remaining knowledge on Beta SP VTRs and I've never heard
> of this question before. Are you saying that EVERY TIME you randomly
> stop playback, it lands on field 2?
> As background, there IS a relationship between the CT phase and field
> order. But beyond that, the mind gets fuzzy due to age.
>
> Dennis Degan, Video Editor-Consultant-Knowledge Bank
> NBC Today Show, New York
>
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