OPTION
05
TV SYNC SEPARATOR
The information
and
instructions presented in this part apply only
to
use
of
the
4658
Option
05
instrument in
TV
applications.
GENERAL INFORMATION
Option 05 provides the instrument
with
front-panel
selection
of
additional processing
of
trigger signals
to
facilitate observation and measurement
of
composite
video
and
related television waveforms. Added circuits
provide amplification, selectable polarity inversion, clip-
ping,
and
vertical-sync recognition.
Two
positions
are
added
to
the A TRIGGER
COUPLING switch:
TV
FIELD
and
TV
LINE. When the A
TRIGGER COUPLING switch
is
set
to
TV
FIELD
or
TV
LINE,
the A TRIGGER SOURCE switch selects the source
of
signals
to
be
processed
in the Sync Separator. This
includes NORM (composite vertical signal),
CH
1,
CH
2,
EXT,
or
EXT/10
(LINE
source
is
not
a usable function
with
TV
FIELD
or
TV
LINE coupling).
When
the A TRIGGER COUPLING switch
is
set
to
TV
FIELD
or
TV
LINE,
the
output
of
the Sync Separator
is
automatically applied
to
the A
Sweep
Trigger circuits,
and only this
signal
may
be
used
for
triggering the A Sweep.
For B Sweep, the horizontal sync signal (line-rate sync)
from the Separator
is
fed
only
to
the
TV
LINE
position on
the B TRIGGER SOURCE switch, which may
be
selected
at the option
of
the user.
The
Option
05
circuitry
may
be
operated either
from
normal sync-negative composite video
(with
the A
TRIG-
GER SLOPE switch at
-)
or
from
inverted video (SLOPE
switch
set
to
+).
This applies
to
most standard broadcast
systems using
from
405
to
819 lines, 50
or
60
Hz
field
rates
or
to
closed-circuit systems using up
to
1201 lines and
60
Hz field rates.
To
optimize video measurements, the vertical amplifier
AC
input
coupling capacitors
are
increased from 0.02
to
0.2
J.LF.
The larger physical
size
of
these
capacitors increases
the
input
shunt capacitance, which
is
normalized at 24
pF.
98
465B/DM44
Operators
@
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