Sony BVU-950 - Page 34

Bvy.920
FOR
TRAINING
PURPOSES
ONLY
Section
2.
DYNAMIC
TRACKING
-PRELIMINARY-
2-2-2. Jumping Control SUBJECT TO CHANGE
Jumping control refers to determination of height of head at entry to drum for various tape speeds.
Fig. 2-4 shows operation of head at x2 FWD speed. During normal playback, head A sequentially traces tracks Al,
A2, etc. At x2 speed, however, head A jumps either track A or B, resulting in tracks Al, A3, etc., or B1, B3, etc.,
being traced.
Moreover, if the head is not at same height as the track, noise will appear on the picture or it will become impossible
to fetch V SYNC. To jump to correct position, CTL signals and information about the capstan FG are used to control
voltage applied to DT head.
Fig. 2-4. Jumping Trace in Two Times Normal Tape Speed
Fig. 2-5. Jumping Control
TRACK END POINT
TAPE PATTERN—,
Eg
TRAC
BEGINNIN
POINT
TRACING a aS
CENTER VIOEO HEAD
4-18