Not all JVC's have the timebase corrector. Their top of the line consumer grade unit seems to always have it. Currently I think its this one.
http://www.jvc.com/product.jsp?model...6935&pathId=49
Theyre kind of expensive, but once I figured out what the problem was, It seemed like a good solution. I wanted something that would really work with a roundie. Other brands make VCRs with a timebase corrector, but usually only in studio grade. Thats *really* expensive. Anyway I was looking around Seattle for what was then the TOTL JVC consumer grade unit (similar to the link above). Nobody had one in stock, but I found a cheaper model JVC that had the timebase corrector. It was a demonstrator, so I even got a discount. It isn't here where I can look at it right now but I think its this one.
http://www.jvc.com/product.jsp?model...9&archive=true
This is the best video I have ever seen come off of VHS. Those timebase errors also come across as chroma phase errors on a line by line basis. When you correct it, the chroma gets better too. You probably wont believe how much difference until you see it.
The white blocks on the DVDs are the copy protection. The first few lines of a NTSC picture are supposed to be black. The copy protection works by putting some white blocks in these first few lines, and turning the level up and down. This fools a VCR into turning the recording level up and down, making a copy unwatchable. This copy protection isnt really in the video on a DVD, It's added on playback. Certain DVD players have the ability to have it turned off. Look around on the internet, I'm sure you'll find some.
The reason our old sets display the blocks is that the beam is still in retrace during those first few lines. Thats why the lines were originally specified black.
Teletext does the same thing. So does the copy protection on VHS. Fortunately the blocks are not nearly so bright on VHS.
There are devices that can replace all the sync pulses and the black lines at the beginning and the end of the picture. These are sold to TV stations and video production facilities who might want to salvage some video off some stretched or badly recorded tape. I've heard some multistandards converters can do this, too.
Beware of cheap black boxes marketed mainly to people who are trying to copy tapes. They are unlikely to replace the sync and the first few lines of the picture.
It might also be possible to fix this at the set level. If yould could blank the CRT beam through the blanking interval and continue blanking through the first few lines, that would probably work. I havent tried it.
John