11-08-2020, 12:54 PM
(This post was last modified: 11-08-2020, 12:56 PM by Yellowtriumph.)
Concerning the GVG vertical clamp, I assumed at the time that as the desk was originally NTSC in design the americans were not concerned about such 'exotic' matters as field sequences and it didn't occur to them someone else might be! Hence no reason not to use any line in the vertical interval. Of course you have now identified that as Line 7 - thank you.
The story of subcarrier and line syncs not being locked to one another and causing problems with colour VTR's was told to me first hand by an engineer of the 'correct' vintage. I believe it was somewhat officially referred to as 'Non-phased colour' at the time? Ring any bells? He also designed his own Quad tape cue tone Editor (!) - quite an amazing bit of design I would think so you could add the acronym 'Ghoste' to Ampex's Editec and RCA's TEP.
I'm wondering how the Tek vectorscope was able to 'discover' and accurately relate the Sc/H phase? From distant memory wasn't it defined by the extrapolated subcarrier crossing the leading edge of line sync 1 within +- 45 degrees? Too long ago now for me to beat myself up about it! You are obviously the 'go to' guru!
Definitely used the Cox 350 and 650. I see you say you worked for Cox Electronics. Please don't tell me you worked on the T series of mixers? If the answer is 'yes' I can't relate a story I'm afraid as it would be too painful for you.
The issues arising from Quad and Sc/h phase are both simple and complex at the same time. A 'run of the mill' editing machine will happily edit all day long seeking only to maintain the 4 field sequence over the edit because it will internally correct any incorrect Sc/h errors within its colour timebase corrector by moving the off tape picture by half a cycle of subcarrier as required. It's only when you are seeking to perform an animation edit ( a sequence of edited frames) or inserting pictures within an existing picture sequence that issues and considerations arise. I think this would go beyond the scope of this thread and to be honest is of no interest to anyone so I will desist.
The story of subcarrier and line syncs not being locked to one another and causing problems with colour VTR's was told to me first hand by an engineer of the 'correct' vintage. I believe it was somewhat officially referred to as 'Non-phased colour' at the time? Ring any bells? He also designed his own Quad tape cue tone Editor (!) - quite an amazing bit of design I would think so you could add the acronym 'Ghoste' to Ampex's Editec and RCA's TEP.
I'm wondering how the Tek vectorscope was able to 'discover' and accurately relate the Sc/H phase? From distant memory wasn't it defined by the extrapolated subcarrier crossing the leading edge of line sync 1 within +- 45 degrees? Too long ago now for me to beat myself up about it! You are obviously the 'go to' guru!
Definitely used the Cox 350 and 650. I see you say you worked for Cox Electronics. Please don't tell me you worked on the T series of mixers? If the answer is 'yes' I can't relate a story I'm afraid as it would be too painful for you.
The issues arising from Quad and Sc/h phase are both simple and complex at the same time. A 'run of the mill' editing machine will happily edit all day long seeking only to maintain the 4 field sequence over the edit because it will internally correct any incorrect Sc/h errors within its colour timebase corrector by moving the off tape picture by half a cycle of subcarrier as required. It's only when you are seeking to perform an animation edit ( a sequence of edited frames) or inserting pictures within an existing picture sequence that issues and considerations arise. I think this would go beyond the scope of this thread and to be honest is of no interest to anyone so I will desist.
