Tektronix 543B, Instruction Manual

Page: 33 / 90

Calibration — Type 543B/RM543B
MAGNIFIED position and reposition the vertical trace to the
exact horizontal center of the graticule. (The HORIZONTAL
POSITION controls will appear extermely sensitive to touch
in the X100 position.) Now turn the HORIZONTAL DIS­
PLAY switch back to the NORMAL (X1) position and adjust
SWP MAG REGIS R359 so that the trace falls exactly under
the cente.r graticule line. Repeat this adjustment several
times to obtain exact coincidence of the trace for both
positions of the HORIZONTAL DISPLAY switch. Recheck
step 13 before continuing to step 18.
Set the HORIZONTAL DISPLAY switch to NORMAL (X1),
the triggering controls for a stable display and the INTEN­
SITY control for normal brilliancy. Position the start of the
display to the left side of the graticule. Observe the marker
that appears near the center of the graticule and position
the display so that the center marker is aligned with the
center graticule line. Then turn the HORIZONTAL DISPLAY
switch to the X100 SWEEP MAGNIFIED position and posi­
tion the marker near the center graticule line so that ihe
leading edge is exactly aligned with the center graticule
line. Turn the HORIZONTAL DISPLAY switch through all
SWEEP MAGNIFIED positions back to NORMAL (X1) and
observe the leading edge of the marker; it should remain
stationary, aligned with the center line of the graticule.
18. Check Sweep Rates — 1 msec to 5 sec
With the HORIZONTAL DISPLAY switch set to NORMAL
(XI) and the triggering control set for a stable display,
check time base sweep rates according to the following
table:
TIME/CM
Switch Setting
Time Markers
Markers
Displayed
.1 mSEC 100 μsec
1 /cm
.2 mSEC 100 μsec 2/cm
.5 mSEC 500 μsec 1 / cm
1 mSEC 1 msec 1 / cm
2 mSEC 1 msec 2/cm
5 mSEC 5 msec 1 /cm
10 mSEC 10 msec 1 /cm
20 mSEC
10 msec
2/cm
50 mSEC
50 msec
1 /cm
.1 SEC 100 msec 1/cm
.2 SEC
100 msec
2/cm
.5 SEC
500 msec
1 /cm
1 SEC
1 sec
1/cm
2 SEC
1 sec
2/cm
5 SEC
5 sec
1 /cm
19. Check Variable Time/Cm Control and Uncali­
brated Neon.
The VARIABLE control provides for a complete range of
control between the calibrated TIME/CM steps. To check
the operation of this control, set TIME/CM to 1 mSEC
CALIBRATED. Connect 5 msec markers to the vertical input
connec'or and trigger the oscilloscope for c stable display
consisting of 1 marker/5 cm. Next, turn the VARIABLE
control fully counterciockwise. The display should now con­
sist of markets every 2 cm or less. Check to see that the
UNCALIBRATED neon indicator lamp is lit in all positions
of the VARIABLE control except when switched to the CALI­
BRATED position.
Set the front-panel controls as shown in Table 5-3 before
proceeding with step 20.
TABLE 5-3
Crt Controls
INTENSITY
FOCUS
ASTIGMATISM
SCALE ILLUM
Usable level
As is
As is
As is
Time Base
TRIGGERING LEVEL
STABILITY
TRIGGERING MODE
TRIGGER SLOPE
VARIABLE (TIME/CM)
TIME/CM
HORIZONTAL DISPLAY
SINGLE SWEEP
0
Clockwise
AC
-PINT
CALIBRATED
.1 mSEC
NORMAL (X1)
NORMAL SWEEP
Other Controls
HORIZONTAL POSITION Midrange
VERNIER (HORIZONTAL
POSITION)
EXTERNAL HORIZONTAL
VOLTS/CM
Midrange
10
VARIABLE (EXTERNAL
HORIZONTAL VOLTS/ CM) CALIBRATED
AMPLITUDE
CALIBRATOR
TU-7
Verfical Position
Test Function
Variable
Other Controls
OFF
Centered
Low Load
Adjust for desired
amplitude
As is
20. Adjust Time Base Sweep Rates 50 μsec /cm to
0.02 μsec /cm.
Apply 10 µsec markers from the Type 180A to the vertical
input connector, and adjust the triggering controls for a
stable display. Turn the HORIZONTAL DISPLAY switch to
X5 SWEEP .MAGNIFIED and horizontally position the trace
so tha t the first time marker is aligned with the center
graticule line. Then switch the TIME/CM switch to 50 μSEC
and check for horizontal shift of the first marker. If shift
occurs, adjust C337 (see Fig. 5-3) until the first marker of
both the .1 μSEC and 50 µSEC positions occur at the same
point.
Turn the HORIZONTAL DISPLAY switch to NORMAL
(X 1 ), Time Base A TIME/CM to 10 μSEC and proceed with
the following adjustments:
5-7