ignored_mailbox at yahoo.com.au
Fri Apr 14 10:48:06 UTC 2006
>> Not really a hi-tech solution, but I always fix this problem by taping
>> a piece of black cardboard across the bottom of the monitor or TV.
I've done the same when a friend has insisted I watch some video that
was recorded on a crap VCR that would never track properly.
> Thats the head switching point, and the video from the head just coming
> onto the tape isn't synchronized to that of the opposite head leaving
> the tape, hence the blur as the digital circuitry in todays vcr's
> scramble to play catchup.
If it's being digitised, then it ought to be getting time base corrected
at the same time. If done correctly, it ought to be a very minor glitch
on one line (the first change over), and sometimes covered up
completely. Unlike analogue playback, where it and everything below the
switch point flag weaves.
> Back when broadcasters were using the u-matic format, the consumer
> grades of that stuff did that too, but it didn't take us techs long to
> find the programming jumper pin on the system synch chip and set that
> head switch point fwd 3-6 lines, putting it down into the vertical
> interval and truely out of sight.
I'd always understood that (at least over here, using PAL), that Hi-Band
Umatic did the switching during the blanking period, as a normal thing,
rather than just before the vertical sync (as Low-Band and domestic VCRs
I think you'd have to move it more than what you said, though.
Generally, the switching point was about that many lines before the
vertical sync. I really don't think that you want the switch actually
*during* the vertical sync.
To make such a modification sucessfully, you'd have to adjust the
recorder and the player, it'd be no good trying to switch a player
differently than how the recorder wrote to the tape, unless there
happened to be overlap.
> When I was refering to consumer grade, like the Sony 2800's, I
> was arbitrarily drawing a line at the about $6k mark as the broadcast
> stuff for 5 to 10 grand more, already had it moved out of sight.
> Selling point you understand... But it was the same chipset, with
> marginally better mechanics wrapped around it.
I was surprised to find out the age of some of the Umatic gear I'd used
at once place. It was a good 10 years older than I expected, and still
going like a tank. Being built like one must have helped. ;-)
I've never had Hi-Band myself, I used another format, but did score an
old Low-Band edit suite for a few dollars several years back (a
Panasonic 9600 & 9660, I think that's the player model, with a simple
controller, too). It was quite good for what it was, not the best of
the bunch (of the various Umatic systems available), but still gave
quite good quality results. I've even got the full service manuals for
it, so it's personal interest value is still there, even though the
machines have stopped working due to mechanical problems: The cassette
loading drives whirr but things don't move (the cassette loading deck,
and the tape loading halo mechanisms). They're too much of a huge beast
for me to want to pull them apart, and I don't have a real need to keep
it working. I bought it for the novelty value when I already had a much
better edit suite, but still had some old Umatic tapes. I should
probably pass it on to someone wanting to restore them, I'm sure there's
people who still want them, and they do take up a lot of space!
(Currently running FC4, occasionally trying FC5.)
Don't send private replies to my address, the mailbox is ignored.
I read messages from the public lists.
More information about the users