Tektronix 2246 User Manual

Boy
ae
nd En
4
2. Select CH 1 for display using the VERTICAL MODE
buttons, and set the Input COUPLING for CH 1 and CH 2
to DC. AC may be used if the signals to be measured are
riding on a de voltage, but set both inputs to the same
coupling. AC coupling produces some signal phase shift,
especially at lower frequencies.
3. Set the CH 1 VOLTS/DIV control to display the
reference
waveform
with
about
five
divisions
of
amplitude.
Vertically center the waveform.
4,
Set
the
A
SEC/DIV
setting
(in
A
Horizontal
MODE)
to
display
at
least
one
complete
reference
waveform
period
and
no
more
than
two
{if
possible).
An
excessive
number
of
cycies
of
the
reference
waveform
in
the
display
reduces
the
user's
ability
to
make
an
accurate
reference
setting.
(Triggering
on
the
negative
siope
of
the
sine
wave
may
position
the
waveform
correctly
within
the
graticule
area
for
ease
in
measurement
when
viewing
a
single
cycle
of
the
reference
signal.)
5.
Press
the
CURSORS
front
panel
button
to
display
the
Cursor
measurement
choices.
6.
Select
[I+
PHASE-
A
second-level
phase-
measurement
menu
is
then
displayed
with
two
choices:
one
to
continue
the
phase
measurement
and
one
to
set
the
360
degree
reference.
Assume
the
present
reference
setting
is
not
correct
(if
it
were,
selecting
l-
PHASE
-i
again
continues
the
measurement
using
the
present
refer-
ence
value).
7.
Press
l-
SET
360°
-i
to
activate
the
reference
set-
ting
function.
The
position
of
the
displayed
cursors
when
l-
PHASE
+!
is
again
selected
defines
the
full
waveform
period
(360
degrees).
8.
Position
the
first
vertical
cursor
to
the
point
that
the
reference
waveform
crosses
the
center
horizontal
graticule
line
in
the
positive
direction
(see
Figure
6-14A).
The
Hor-
izontal
POSITION
control
may
be
used
as
necessary
to
center
the
waveform
period
in
the
viewing
area.
9.
Position
the
A
cursor
to
the
second
positive
cross-
ing
of
the
center
horizontal
graticule
line
by
the
reference
waveform
as
shown
in
Figure
6-14A.
10,
Select
I-
PHASE
-i
to
set
the
new
reference
value
and
continue
the
phase
measurement.
REV APR 1987
Measurement
Processes
and
Applications—2246
Operators
11.
Apply
the
phase-shifted,
sine-wave
signal
to
be
measured
to
the
CH
2
input
connector
using
a
10X
attenuator
probe,
and
turn
CH
2
VERTICAL
MODE
on
to
display
the
signal.
12.
Set
the
VOLTS/DIV
and
VOLTS/DIV
VAR
controls
to
match
the
amplitude
of
the
phase-shifted
signal
to
that
of
the
reference
waveform
as
shown
in
Figure
6-14B.
Use
the
VERTICAL
POSITION
contro!
as
necessary
to
align
the
two
waveforms
vertically,
13.
Reposition
the
second
cursor
to
the
first
positive
crossing
of
the
phase-shifted
signal
and
read
the
phase
difference.
NOTE
For
increased
resolution
of
the
phase
measurement,
the
sweep
many
be
increased
and
both
cursors
repositioned
to
the
measurement
points
(see
Figure
6-14C).
The
X10
MAG
feature
may
also
be
used
in
a
similar
manner
by
placing
the
measurement
points
at
the
center
vertical
graticule
line
before
pressing
the
X10
MAG
button
(you
may
want
to
reduce
the
A
SEC/DIV
setting
prior
to
turning
on
the
X10
MAG
feature).
DELAY
TIME
MEASUREMENTS
The
delay-time
readout
(DELAY)
is
displayed
when
the
Horizontal
MODE
is
ALT
or
B
and
no
menu-selectable
measurement
mode
is
active.
(Push
CLEAR
DISPLAY
to
turn
off
menu-selected
measurements.}
Delay
time
is
set
using
the
l-
OR
DELAY
control.
In
RUNS
AFTER
B
Trigger
MODE,
the
delay
time
from
the
start
of
the
A
Sweep
to
the
start
of
the
B
Sweep
is
set,
and
the
top
line
of
the
readout
displays
the
time
delay
between
the
start
of
the
A
sweep
and
the
start
of
the
B
Sweep.
For
triggered
B
Sweep
modes
{AUTO
LEVEL,
NORM,
and
TV
LINE)
the
delay
time
to
the
arming
of
the
B
trigger
is
set,
not
the
displayed
delay,
and
a
question
mark
(?)
is
displayed
in
front
of
the
delay-time
readout
value.
In
ALT
Horizontal
MODE
with
the
A
and
B
SEC/DIV
settings
set
to
the
same
sweep
speed,
there
is
no
Alter-
nate
B
trace,
and
the
length
of
the
intensified
zone
appearing
on
the
A
Sweep
trace
is
1/100
of
the
SEC/DIV
setting.
The
position
of
the
dot
on
the
A
trace
indicates
the
position
of
the
DELAY
setting.
The
dot
may
be
use
to
6-15

Tektronix 2246 Specifications

General

Brand	Tektronix
Model	2246
Category	Test Equipment
Language	English