Sony BVH-2000, Operation And Maintenance Manual

Page: 294 / 505

(5-5-2. Principle of Arbitrary Playback)
3. Track Jump Control
The video offset of the video tracks, as defined by the type C
format, is 2.5H for NTSC/PAL-M systems and 3.5H
PAL/SECAM systems. When the head has jumped to the
adjacent track, the phase of the playback video signal shifts
2.5H (3.5H). in order to make effective
TBC window or secure an overlap, controlled must be exercised,
no matter what the speed, so that the phase of the playback
video signal does not shift excessrverv
The PBVX2 signal (see Section 5-5-3. Item 6), which is detected
from the equalizing pulse indicating the phase of the video
serves to which track traced.
"'I""rrn,r:oll,r
however, the PBVXI signal, which operates stably, is used as the
V reference although, when something goes wrong with the
FHX signal from the TBC, is switched
to the PBVX2 signal. When the phases of the PBVXl and
PBVX2 signals shift for more than 4 fields in succession, the
of the PBVXl is for using the IN
PHASE generator by the timing of the PBVX2 signal.
Overlap tracing is required for the video tracks for slow
PI2lVbaC}C,while
different speed above the lx normal speed.
niavback at 1.2x
The path of the DT head, which is fixed with respect to the
recordmz tracks (solid on the tape, shown as dotted
lines. In order for tracking to be conducted the DT
head must be displaced from the dotted lines to the thick lines.
The position and size of the head jump are controlled by the
head's writing speed information relative to the tape, which is
from the and difference
information, which in turn is detected from the relauonstup
between the DT playback signal and reference signal, which in
turn is detected from the
video signal.
VIDEO OFFSET: NTSC/PAL- M =2.5H
~L/SECAM :~5H
TRACKING AND HEAD JUMP IN ARBITRARY PLAYBACK
Head trace when the Tracklnoerror Head trace when the
tope is stoppedCSTILL). Ispeed Is 1.2 x normal.
DT Headtrace
DT HEAD
TRACKING
ERROR VOLTAGE
(BIMORPH DRIVING VOLTAGE)@
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BVH-2000(U/C)/PS/PM
BVH-2180(U/C)/PS/PM
5-5-3
DYNAMIC TRACKING SYSTEM
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