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Posted by Harry Kiri on 11/22/05 12:37
"Harry Kiri" <no_spam@no_spam.com> wrote in message
news:437d11c4$0$22520$5a62ac22@per-qv1-newsreader-01.iinet.net.au...
> On the other hand, at LP the drum would have to rotate at a
> lower speed too, so the voltages induced in the heads should
> theoretically be significantly lower, (flux change/unit time
reduces),
<snip>
> Regards,
> Hughy
No one picked up my deliberate mistake? :-)
Thinking further, a head rotation speed change would be undesirable,
the head rpm (probably) should remain constant at either LP or SP.
Maybe they use FSK to commit the data to tape? Perhaps 1 frequency
pair for video and 1 for audio? For arguments sake, using, say, a sub
carrier of 1MHz to represent a 0 and 1.001 MHz for a 1. A tape that
was travelling slightly off spec, might shift one or both audio FSK
frequencys outside the filter B/W. Nah ... that's not right either.
Head RPM would be the critical factor in any shift in FSK outside B/W,
not tape speed.
The system probably isn't as uncomplicated as a couple of FSK's, Sony
et al have probably developed such clever recording electronics that
they'd make *our* heads spin faster than the cameras trying to follow
their method :-)
None of this conjecture explains the intermittent 1 or 2 frame audio
dropout that the odd VX2K seems to develop after a while.
Any one else experience this intermittent dropout?
Regards,
Hughy
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