Not being an electrical engineer, what is the black vertical bar in the monitor of the play back machine. The right hand monitor doesn't have it so I'm guessing this is some sort of phase shift?
The monitor on the VR-2000B can display the video signal on different stages through the electronics. I am guessing at that moment it was displaying the video signal before it got phase corrected.
Greetings Gents
I started as a broadcast tech for the Australian national broadcaster (ABC) back in the early 1980's. In 1984 on my first day in videotape as a trainee was the day they decommissioned the last VR2000 and moved it out of videotape. From memory they had to bring in a crane to get down to ground level.
The VR2000 is a quadruplex VTR and records video at right angle to the direction of tape travel. There are 4 video heads on the head wheel and each head plays/records 16 lines of video as it passes over the tape. The saw tooth pattern you can see is the video from each head.
Before recording or playing a videotape the machine has to be set up with electronic (head amp gain) and mechanical (tip penetration and guide height) adjustments to normalise the signals onto the tape. There are other adjustments but that's all I can remember.
apollo16uvc is correct about the reason for the delay of the video signal. I'm a bit hazy (it's been 30 years) but the delayed picture was a setting that showed the video signal pre timebase corrector. You would physically adjust the position of the headwheel tip penetration and guide height to minimise that sawtooth as much as possible to reduce the amount of work the timebase corrector had to do. They could only correct a few microseconds of error.
From memory the VR2000 we had was originally black and white but was later updated to colour and had the editor option added. There was a oscilloscope permanently sitting next to it for the morning alignment.
We were still using later model quad machines (AVR-1, AVR-2, ACR-25) well into the 90's for production and then archive.
Quadruplex park website is a good resource for quad vtr's for those who are interested.
http://www.lionlamb.us/quad/ampex.htmlThat generation of ampex VTR relied on a combination of electronics, mechanics and pneumatic engineering that was almost artistry. Ahh, memories.
Regards
Ian
