[QuadList] Blanking Issues

[Bill Carpenter]

Yes, Park,

Everything that has been stated before, by everyone is correct, the "C" format was based on the moving head technology, which changed the dropout position as a result of the greater interchange stability of the format. We added the "sync" head as an option, to make our machine the same as Sony. 
I was not part of the "C" format related effort, since I had be given the AVR-3, the last quad, and the largest retrofit program in Ampex's history. It was developed to be a great machine, but had a product manager who didn't understand engineering and was also more interested in the editing system we were working with a Canadian Company, Central Dynamics Limited.
My first "C" format product was the VPR-20, with was the VPR-10, which did not get to market, revised to "C" format. It was a very good, but heavy "porterable"( my word, which meant, give somebody $5-$10 and let them carry the 50lb unit)

Bill Carpenter




________________________________
From: C. Park Seward <park at videopark.com>
To: Quad List <quadlist at quadvideotapegroup.com>
Sent: Sun, February 7, 2010 9:02:24 AM
Subject: Re: [QuadList] Blanking Issues

Yes, that is the way I remember. Sony insisted on recording the entire video. My Ampex machines did not have the sync head and I never missed it.

Bill Carpenter may shed more light.


Best,
Park

C. Park Seward
Visit us: http://www.videopark.com




On Feb 7, 2010, at 7:50 AM, Wayne Watson wrote:

It was in the SMPTE standard. Ampex made it an option and Sony made it standard. The concern was that something in the future might need the V.I. However in type C only lines 4 to 14 were missing so VITC and VITS were still there. I think there was also an issue where Sony did not want tp pay re a patent Ampex had on control track update (or something like that)and needed the V.I. to do it their way. Can anyone shed more light on that?
>
________________________________
From: quadlist-bounces at quadvideotapegroup.com [quadlist-bounces at quadvideotapegroup.com] On Behalf Of Scott Thomas [scottgfx at mac.com]
>Sent: Saturday, February 06, 2010 11:59 PM
>To: Quad List
>Subject: [QuadList] Blanking Issues
>
>
>Talking about Type-C for a moment; I can't remember if it was Sony or Ampex (or both?), but they had a separate "sync" head on the scanner. I'm assuming that was to have a clean sync pulse on the head switch? A problem obviated by a TBC?
>
>
>Scott Thomas
>
>On Feb 6, 2010, at 5:20 PM, Don Norwood wrote:
>
>Hi Park:
>> 
>>All of the Type-A 1" machines up thru the VR-7800 had the switch above the vertical interval.  The VPR-7900 was the first to place it in the vertical.  Remember also that the Type-A machines are single head, so there is more than a "switch", there is a dropout for several lines.  The VR-660 is a 2-head design so there is a switch and no dropout.
>> 
>>When Sony made their first 1/2" machines, there was apparently some "reverse engineering" done on their Ampex predecessors.  Although the Sony machines were 2-head, they had a "blanking" circuit that covered up the switching point and produced a totally blank area in the same location as the Ampex Type-A.  There was no logical reason for that other than replicating the output signal of the Ampex.  The practice was discontinued in subsequent models.
>> 
>>Don Norwood
>>www.digitrakcom.com  _______________________________________________
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