Calibration— Type 1A1
1
t
1
1
1
-C o rre c t (Optimum fla t top)
-
-
- c
(A)
Sweep Rate: 0 .5 msec/cm
-
-
:
i
i
i
i
:
. Incorrect (No fla t top)
1 -
n ;
—
r
—
T
'
:
IB)
Sweep Rate: 0.5 msec/cm
r n
i
i
i
.In c o rre c t (No fla t top)
'
-<C
7 -
—
1 w
(C)
Sweep Rate: 0 .5 msec/cm
-
-
V -:
-
-
\
r
1ncornJCt
(Sp ike a nd nc flat top)
-
-
r -
. n
.
Sweep Rate: 0.1 msec/cm
-
-
/
^ - N
\
-
-
(
ect
off a
top)
1
~
)
Incori
t roll
flat
r
'
(Fas
nc
id
-
-
-
-
Sweep Rate: 0.1 msec/cm
Fig. 7 -2 5 . (A ) Correct waveform obtained when normalizing the
input capacitance of the Type 1A1; square-wave repetition rate is
2.5 kHz.
(B) and (C) show incorrect waveforms.
d. Set the Type 106 Amplitude control to produce a dis
play 4 cm in amplitude.
e. Set the oscilloscope Triggering Level control to ob
tain a stable display and use the Type 1A1 Channel 1 PO
SITION control to center the display.
f. Set the Type 106 Symmetry control to obtain a sym
metrical waveform display. If necessary, adjust the Multi
plier control to obtain the 2.5 kHz output repetition rate.
g. CHECK— The waveform should have a flat top similar
to the illustration shown in Fig. 7-25A. Overshoot or roll
off on the top front corner of each cycle of the waveform
should not exceed 3% peak to peak or 0.9 mm on a 3-cm
waveform. Using Table 7-2 as a guide, check for a square
corner and flat top on the top front corner of the waveform
in all the other listed VOLTS/CM switch positions. Main-
Fig. 7 -2 6 . Waveform (A ) shows the desired result obtained when
an attenuator frequency-compensating capacitor is adjusted correctly.
Waveforms (B) and {C ) show effect obtained when both the shunt
and frequency-compensating capacitors are misadjusted.
Square-
wave repetition rate is 2.5 kHz.
tain a 4 cm display amplitude except for the 20 VOLTS/
CM position.
h. ADJUST— Using Table 7-2 as a guide adjust Channel
1
input capacitance and frequency compensation capacitors
(see Fig. 7-27) for optimum flat top and square corner (see
Figs. 7-25A and 7-26A). Maintain a 4 cm display (except
on the 20 VOLTS/CM switch setting where approximately
3 cm is the maximum obtainable amplitude). Use the cali
bration accessories where indicated in Table 7-2.
Waveforms shown in Figs. 7-25B and 7-25C shows the
effects obtained when an input shunt capacitor such as
C104 or C105B is misadjusted. Waveforms shown in Figs.
7-26B and 7-26C show two effects obtained when an at-
®
7-23