Tektronix 543B, Инструкция по эксплуатации

Страница: 32 / 90

Calibration — Type 543B/RM543B
11. Trigger Level
Remove the jumper and turn the TRIGGERING LEVEL
control until the waveform is triggered at the same point as
that observed when the shorting lead was connected. The
white dot on the TRIGGERING LEVEL knob should point at
0. If it does not, loosen the knob and move if to this posi­
tion. Remove the test lead between the CAL OUT and Ext
Input connectors.
Vertical Position
Test Function
Variable
Other Controls
TU-7
Centered
Low Load
Adjust for desired ampli
tude
As is
12. Preset Adjust
Place the TRIGGERING MODE switch at AUTO and the
TRIGGERING SLOPE switch to +LINE. Connect the dc
voltmeter between the PRESET ADJUST potentiometer wiper
arm (see Fig. 5-3) and ground and turn the potentiometer
fully counterclockwise. Turn the control slowly clockwise
until a trace first appears and note the meter reading at
this point. Continue to turn this control until the trace
brightens and again note the meter reading. Finally, set
the PRESET ADJUST control to obtain a meter reading mid­
way between the two previously noted meter readings.
Front-panel controls should be set as shown in Table
5-2 before proceeding with step 13.
TABLE 5-2
Crt Controls
Usable level
As is
As is
As is
INTENSITY
FOCUS
ASTIGMATISM
SCALE ILLUM
Time
TRIGGERING LEVEL
STABILITY
VARIABLE (TIME/CM)
TRIGGERING MODE
HORIZONTAL DISPLAY
TRIGGER SLOPE
TIME/CM
SINGLE SWEEP
Base
0
Clockwise
CALIBRATED
AC
NORMAL (X1)
+ INT
1 mSec
NORMAL SWEEP
Other Controls
HORIZONTAL POSITION
VERNIER (HORIZONTAL
POSITION)
EXTERNAL HORIZONTAL
VOLTS/CM
VARIABLE (EXTERNAL
HORIZONTAL VOLTS/
CM)
AMPLITUDE CALIBRATOR
Midrange
Midrange
10
CALIBRATED
OFF
13. Normal (XI) Calibration
Apply 1 msec markers from the Type 180A to the vertical
input and adjust triggering controls for a stable display.
Now adjust XI CAL R342 (see Fig. 5-3) for 1 time-marker/
cm display.
NOTE
Any non-linearity present in the sweep will al­
ways be in the first and last centimeter. Conse­
quently all timing adjustments should be made
from the 1 -cm line to the 9-cm line on the
graticule.
14. XI 00 Sweep Magnified Calibration
Turn the HORIZONTAL DISPLAY switch to the X100
SWEEP MAGNIFIED position. Remove the 1-msec markers
and apply 10-µsec markers to the vertical input connector
and adjust X100 CAL R375 (see Fig. 5-2) for 1 marker/cm.
Repeat steps 13 and 14 as there is interaction between
these adjustments.
15. Adjust Horizontal De Shift Compensation
Remove any signal from the vertical input connector of
the TU-7; leave the TIME/CM control at 1 mSEC and set
the HORIZONTAL DISPLAY switch to X100. Turn the
STABILITY control clockwise until the sweep free runs, and
adjust the HORIZONTAL POSITION control so that the
start of the trace coincides with one of the vertical grati­
cule lines. Slowly turn the sweep generator off and on
with the STABILITY control and observe the start of the
trace for drift. Adjust DC SHIFT R365 for minimum drift
in the start of the trace.
16. Adjust Sweep Length
Set the HORIZONTAL DISPLAY switch to NORMAL (X1)
and apply 1 millisecond markers to the vertical input con­
nector. Obtain a stable display with the triggering con­
trols. Position the start of the display to the left edge of
the graticule and adjust the SWP LENGTH R176 (see Fig.
5-3) for a sweep length of 10.5 CM.
17. Sweep Magnifier Registration
With 1 msec time markers applied to the vertical input
connector, turn the STABILITY control fully counterclock­
wise but not to PRESET, and increase the intensity so that a
vertical trace is visible at the left side of the graticule;
then use the HORIZONTAL POSITION control to position
the vertical trace to the horizontal center of the graticule.
Set the HORIZONTAL DISPLAY switch to the X100 SWEEP
5-6