Table of Contents
Advertisement
@
OFF TAPE V-PHASE
lamps
When
producing
time
base
'correction ranges
of ±2
H
and
±6
H,
it is first
necessary
to
have
one or
two
8-line
memory
boards, respectively. (Only one
board
is
provided
with the
model and
the other
boards
are
available as options
BK-2001-)
In
addition,
the phase
of the
VTR playback
output
must be
advanced
4
H
or 8 H, respectively, as average
values
ahead
of
the TBC
outpu
t
phase. If the phase
advance
does
not tally
with
these values, there is no change
in
the
width of
the
correc-
tion
range at
4
Hp-p
and
8
Hp-p,
but
the center value
of the
correction
shifts
and
so
it
appears that
the correction range is
correspondingly narrower.
This point
is
importan
t
especially
when the
correction
range is
to be
made as wide as
possible such
as
with dynamic
tracking
playback
or
rolling
tape
playback.
If the playback
output
phase
shifts
fro
m
the correction range, this
will be translated
into a shift in
the
picture
with
the
TBC
output
in
the
vertical
direction.
The
OFF
TAPE V-PHASE lamps enable
the
VTR
playback
output
phase to
be
checked
to
see if
it is properly advanced
ahead of
the
TBC
output
phase.
ADVANCE:
Lights
up
when
the VTR output
phase
has
been
advanced too
far
ahead.
IN:
Lights up when the
VTR
output
phase
is
correctly
positioned.
DELAY:
Lights
up
when
the VTR
outpu
t
phase is
delayed.
When
the BVH-500 or BVH-1100
is
being employed,
the
VTR
output
phase
is
designed
to
be
correct
without
a
special
signal having
to be
sen
t
from
the TBC
to
theVTR
.
Therefore, whe
n
these VTRs
are
being
used and
the
AD-
VANCE
or
the
DELAY
lamp
lights up,
it
is necessary to
check
on
a
n
oscilloscope whether
the
TBC
correction
range
is
sufficient
for
the
flu ctuation in
the
VTR
output
phase
or
whether
the average
VTR output
phase
is
centered
in
the
correction
range.
If the
phase
is not correct,
adjust the switch
inside the
VTR.
Furthermore,
the VTR output
phase
will
not
be correct
unless
some action
is
taken,
when the BVH-1000, BVU-100 or
BVU-200A
is
being
operated. Therefore,
it is
necessary
to
send
an advanced sync
signal
from
the
TBC to
the
VTR
a
nd apply
the vertical
sync
of the
VTR
with
this
signal.
This
particular
time
base
corrector has
a
built-in
circuit
which
automatically controls
the
advanced
sync phase so
that
the
above
VTR
playback phase
is
brought
properly into
the
center
of the
correction
range. This means
that
it
is no longer
necessary to align the advance sync phase
as it was with
conventional
time
base correctors
when
changing the
tape.
(Manual operations are also
possible using the
in
ternal
selector
switch.)
4
1-8
Hide quick links:
Advertisement
Table of Contents
