Tektronix 2236 - TV Field Signal Display; DELAYED-SWEEP MAGNIFICATION

Operating
Procedures -
2236
Operators
2. Apply the
TV signal
to either
vertical
-
channel input
connector and set the VERTICAL MODE switch to display
the channel used .
C
7. To display a selected horizontal line , first trigger the
sweep on
a vertical
( field ) sync
pulse , then
use the
“ Magni
fied Sweep Runs
After Delay "
procedure in this
part ( steps 5
through
7 ) to
magnify
the
selected
horizontal
line
for a
closer
examination . This procedure is useful for examining Vertical
Interval Test
Signals
(
VITS
) .
3. Set the appropriate VOLTS / DIV switch to display 0.35
division
or
more of
composite
sync
signal .
4. Set the A SEC / DIV switch to 10 us .
8. To
display either
Field 1 or
Field 2
individually
, connect
the TV signal
to both CH 1 and
CH 2 input
connectors and
select BOTH and ALT
VERTICAL
MODE
.
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5. Set the A TRIGGER SLOPE switch to either OUT :
( for positive - going TV signal sync pulses ) or IN : 2 ( for
negative - going TV signal sync pulses ) .
9. Set in A SEC / DIV switch to a faster sweep speed
( displays of less
than one
full field ) . This
will
synchronize
Channel
1 display
to one field
and
Channel 2 to
the
other
field .
NOTE
To examine a TV Line signal in more detail , either the
X10 Magnifier or the Delayed - Sweep Magnification
feature may be
used .
DELAYED - SWEEP
TV
Field
Signal
The television feature of the 2236 can also be used to
display TV Field signals .
Magnification
The delayed -
sweep
feature
of the
2236
can
be
used
to
provide
higher
apparent
magnification
than is
provided by
the X10 Magnifier switch . Apparent magnification occurs as
a result of displaying a selected portion of the A trace at a
faster
sweep
speed ( B
Sweep
speed ) .
The A
SEC
/ DIV
switch
setting
determines
how
often the B
trace will be
dis
played . Since
the B
Sweep can occur
only once for
each A
Sweep , the
A
Sweep time
duration sets
the
amount of time
elapse
between succeeding B
Sweeps
.
1. Preset instrument controls and obtain a baseline trace .
2. Select TV FIELD A TRIGGER mode ( pushed both P - P
AUTO and NORM buttons in ) and set the A SEC / DIV switch
to
2
ms .
3. To display a signal field , connect the TV signal to ei
ther vertical - channel input connector and set the VERTICAL
MODE switch to display the channel used .
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The intensified
zone is an
indication of both the
location
and
length of the B
Sweep
interval
within
the
A Sweep inter
val . Positioning of the intensified zone ( i.e. , setting the
amount of time between start of the A Sweep and start of
the B
Sweep ) is
accomplished
with the B
DELAY
TIME PO
SITION control . With either ALT or B HORIZONTAL MODE
selected and B TRIGGER LEVEL control set fully clockwise
( B RUNS AFTER DLY ) , the B DELAY TIME POSITION con
trol provides
continuously variable
positioning of the
start of
the B Sweep . The range of this control is sufficient to place
the B
Sweep interval at
most any
location within
the A
Sweep
interval .
When ALT
HORIZONTAL
MODE is
select
ed , the B SEC / DIV switch setting determines the B Sweep
speed and
concurrently
sets
the
length
of the
intensified
zone on
the
A trace
.
4. Set the appropriate VOLTS / DIV switch to display 0.35
divisions or more of
composite sync signal .
5. Set the A TRIGGER SLOPE switch to either OUT : -
( for positive - going TV signal sync pulses ) or IN : 2 ( for
negative - going TV signal sync pulses ) .
NOTE
6. To change the TV field that is displayed , momentarily
interrupt the trigger signal by setting the Input Coupling
switch to GND and then back to AC until the desired field is
displayed .
NOTE
o
Gated FREQ ,
PER , WIDTH
, or TOTALIZE
functions
alter the length
of the
intensified zone to
indicate the
gate
interval established
by the
CTM
section , when
the B
sweep is
triggered
.
Therefore
, in
these
cases
the B
sweep
duration
does not
match
that
of
the in
tensified
zone .
To examine a TV Field signal in more detail , either the
X10 Magnifier or the Delayed - Sweep Magnification
feature may be used .
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