Calibration— Type 544/RM544
1
- —
(a) Normal waveform; sweep rate
is 0.1
f i s e
c/cm.
90%
i
■ /■
: / 1
if* l *
:/ ■
I
I
—
10%
—
1
i
|
i
I
(b) Measuring the risetime
normal waveform; sweep
is lOnsec/cm.
of a
rate
r
F
- 7 nsec or faster.
Z S 5
to 35 nsec
r ' "
ni
1-
90°
4 -
K L
u
■ M ♦ f
. —
(c) Effect on waveform when Cl 106 is
misadjusted; sweep rate is 0.1 /isec/
cm.
Fig. 5-11. Check of compensation adjustments for optimum Vertical
Am plifier transient response.
c. Using the oscilloscope HORIZONTAL POSITION con
trol, position the display to start near the graticule
center.
d. Set the TU-7 Amplitude and Vertical Position controls
so the display is vertically centered on the crt and
the amplitude of the step waveform is exactly 4 cm.
TABLE 5-10
Oscilloscope
~ 3.5
~ 5
~ 5
~ 8
INTENSITY
FOCUS
ASTIGMATISM
SCALE ILLUM
TRIGGERING LEVEL
Single Sweep Switch
HORIZONTAL POSITION
VERNIER (HORIZONTAL
POSITION)
Type TU-7
Repetition Rate
Knob pushed in
NORMAL
About —45° from center
Centered
Med
e. Using the TU-7 Vertical Position control, position the
waveform downward about 2 cm for easier visibility
away from the graticule lines.
f. Adjust the INTENSITY control to increase the bright
ness of the display to normal viewing level.
g. Adjust the FOCUS and ASTIGMATISM controls to
produce a well-defined leading top corner on the
step waveform.
h. Examine the waveform for clean transient response.
Typical waveform should appear similar to Fig. 5-1 la.
i. Set the HORIZONTAL DISPLAY switch to XI0.
j. Measure the risetime of the rising portion of the wave
form from the 10% point to the 90% point (see Fig.
5-11b). The risetime should not be any slower than
7 nsec based on a 3-nsec risetime pulse from the TU-7.
(Take into consideration sweep-rate timing error, if
any, and/or geometry in the area where the meas
urement is made.)
k. If the aberrations appear excessive and/or the rise
time is slower than 7 nsec, set the HORIZONTAL DIS
PLAY switch to XI and adjust the high-frequency
adjustments using Table 5-11 as a guide. Since the
adjustments interact, it is necessary to readjust (go
back over) the adjustments several times to obtain a
waveform with good transient response. When mak
ing the adjustments, keep the step waveform verti
cally centered on the crt.
NOTE
To check the overall level and maintain a flat top
when making the adjustments, use the NORMAL
and X I0 HORIZONTAL DISPLAY switch positions as
an aid in checking the waveform appearance.
5-15
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