Sony BVH-2000, Руководство по эксплуатации и обслуживанию

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(5-5-3. DT-04/-05 Board)
9. PBVX Selector
This serves to check the operating status of the sync in -phase
detector at the timing of the REF ADV V signal from the LG
board. When the FHX signal from the TBC is not input or when
the DT system stops operating and the INTEG OFF signal is
output from the head movement detector, the PBVX2 signal is
automatically
selected. Furthermore, the PBVX
selected when the DT system's operation is returned to normal.
PBVX SELECTOR
FROM IC4-0-4
P8VX 1
FROM IC4G-iO
P8VX2
FROM ~
IC41-i3
FROM REF ADV V
228
P BVX 1 is detected.
226: REF ADV V
IC4K-8
IC4K-
IC4K-l0
IC4J-9:D
IC4J-13
IC4J-11
IC4L-11
IC4G-1: TP7
BVH-2000(U/C)/PS/PM
BVH-2180(U/C)/PS/PM
PBVX11s not detected.
~
PBVX2
TP7
10. DT ON/OFF Controller
This circuit controls the of the DT function and
outputs the HOT MODE" which the processmz
of the video signal to the TBC.
The DT system functions under the following conditions:
• HEAD Selector PLAY (22A:DT HEAD
• Drum servo Locked (24A:DRUM LOCK=low)
• VTR PB Mode (27B:OFF TAPE=low)
• Tape speed -Ix to + 3x speed
When the VTR is in the shuttle mode, the tape
is limited to the -Ix to + 3x range the
pin 22A DT HEAD SEL signal (low).
The tape speed is detected by measuring, using one-shot IC5M,
the
of the timer Hz at lx normal speed) input
into pin 31B. IC4M-IO is set low when the tape is in the
-2x to +4x speed range.
The HCAP LOCK" signal, which has been input into pin 25A,
indicates the operation of the capstan servo. When the capstan
servo is locked, this
low, field interval
which are input into shift register IC5-0 from the DT V
generator are counted, and when the capstan servo is locked for
8 or more fields in succession, the IC5-o
Q
output is set high
and TBC's DT is released. When 25A has
been set high, the IC 5-0
Q
output is immediately set low and,
before the head starts jumping or, in other words, while the
subcarrier's continuity is still in tact, the VTR moves into the
DT mode.
DT ON/OFF CONTROLLER
TAPE
DIRECTION
(RL)
TM8 --~~
(RLJ
DRUM LOCK
(CD)
DT HEAD SEL
(LG)
OFF TAPE
(LG)
CAP LOCK
(CD)
r-----------+
DT ~
"X}-e---------..
DT ~
4-0-3
I-----~
IC4M.5L.4-~
lDRUM LOCK, DT·OFFTAPE
'fof'
CAP LOCK
FIELD PULSE
(FR ICSN)
5-5-7
DYNAMIC TRACKING SYSTEM
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