Tektronix T921 User Manual

3 . Set the INTENSITY and
FOCUS controls for the
best defined display .
If the display still appears out of
focus, use a small
screwdriver to adjust the ASTIG control
(through left
cabinet side of T921/T922) for the best
defined
display .
4 . Rotate the
INTENSITY control fully clockwise . The
display will get
brighter and defocus (get thicker) . Return
the INTENSITY
control to the preferred brightness level
.
Ext
Z Axis Input Operation
Forthe T921 orT922
a positive-going signal
will cause a
decrease in intensity,
and a negative-going
signal will
increase the
intensity level of a low-intensity
trace . For the
T922R, an
internal plug allows a
selection of either a
positive-going or a negative-going
signal to cause a
decrease
in intensity . See Service
Information .
X1410 and
Trigger Operation
1 . Note
a display with several cycles of
the PROBE
ADJ
waveform . Rotate the X1-X10 control
fully clockwise
to
X10and note that only one
cycle is visible . Return
control to X1 .
2
.
Set the
SEC/DIV to .1 ms . Position
the start of the
display (left-hand edge) on the
screen . Set the SLOPE
button to +OUT position
. Rotate the LEVEL control
through its range .
The start of the display will move
along
the positive
(rising) slope of the signal until the
display
becomes
unstable .
3 .

Set the LEVEL control
for a stable display that
starts
at about the middle of
the slope .
Now set the
SLOPE button to -IN position
. Rotate the
LEVEL control
through its range . The start of
the display
will move along the negative
(falling) slope of the signal
until the display becomes
unstable .
4 .

Set the LEVEL control for a stable
display that starts
at about the middle of the slope
.
5 . Set the MODE
switch to NORM . The display
should
start on
the negative slope . In the NORM mode
the display
will disappear if the LEVELcontrol is
improperly adjusted .
6 . Set the SLOPE
button to +OUT position . The
display should start on
the positive slope .
7 . Disconnect the probe from the
instrument . Set the
CH 1 AC-GND-DC switch to
GND . The trace should
disappear .
REV
. BJUL 1977
Example :
Operating Instructions-T921/T922/T922R
8 . Set the
SOURCE switch to LINE
. If a trace doesn't
appear, adjust
the LEVEL control
until a trace appears .
9 . Set :

SOURCE

INT
MODE
AUTO
CH 1 AC-GND-DC

AC
The instrument is now ready
to operate when signal
is
applied to the CH 1 input
.
PROBE
COMPENSATION
An incorrectly-compensated
probe is one of the
greatest sources of operator
error . Most attenuator
probes
are equipped with
adjustments to ensure
optimum
measurement accuracy
.
Some
probes are compensated by
using a small,
insulated
screwdriver through an
access hole to the .
compensation adjustment .
Other probes may have an
adjustment system similar to
that shown in Fig . 2-10 .
Probe
compensation is accomplished as
follows :
Set the appropriate VOLTS/DIV
switch to .1 V, the AC-
GND-DC switch to DC,
and the SEC/DIV switch to
2 ms .
Connect the probe
to the vertical input
and touch the
probe tip to
the PROBE ADJ connector
. Notice a display
similar
to
those shown in Fig . 2-11
. Adjust the probe for the
correct compensation The
effects of incorrect probe
compensation on three types of
signals are illustrated
in
Fig . 2-11 .
APPLICATIONS
Peak-to-Peak
Amplitude Measurements
To
measure the amplitude of
a signal, multiply
the
vertical deflection (in
divisions) by the VOLTS/DIV
switch
setting . (Use VOLTS/DIV
window to match attenuation
factor of probe used .)
The display
amplitude is 3 divisions (see Fig .
2-12) and
the
VOLTS/DIV switch is set to .5 V .
Substituting the given
values :
Amplitude =3
divisions x 0 .5 volt/division =

1 .5 V p-p
2-1 3

Tektronix T921 Specifications

General

Brand	Tektronix
Model	T921
Category	Test Equipment
Language	English