c. Adjust the Trace Alignment R1035 (see Fig. 6-8) so the
CAUTION
trace is aligned with the horizontal graticule centerline.
When changing the input power selector range,
the power should be removed by either turning
the autotransformer power switch to off, or by
disconnecting the input power cord to the Type
491.
Typical Ripple
Amplitude
Voltage Regulation
Supply
≤1 m V
9.9 to --1 0.1 V
-10V
≤2 m V
+10V
9.7 to 10.3 V
≤5 m V
+150 V
145.5 to 154.5 V
c. The following calibration steps do not require a line
voltage control unit. Return the Line Voltage Selector to
the operating range for the existing power source voltage.
The Type 491 may be connected directly to the power source
for the remainder of the calibration.
o
6. Adjust Trace Alignment
a. Test equipment setup is given in step 5.
b. Position a free running trace to the graticule center
horizontal line.
Location
of
Trace
Rotation
R1035.
