Section 5 Maintenance
5-6
5-23. Analyzer Level Flatness. The level flatness test is
made in the level ratio mode where the ratio reference is
set at a frequency of 1 kHz and at a specific test level. The
frequency is then varied and the resultant relative
amplitude measurements are recorded.
5-24. Depress the LCL/INIT key to initialize the instru-
ment and enter special function 17 to enable the slow
detector mode. Connect the Wideband Calibrator output
using the balanced cable and adapters to the Analyzer HI
and LOW inputs and connect the 50 ohm load across the
binding post adapters. Perform the following procedure
for each test level listed in Table 5-5.
a. Enter the Calibrator level at a frequency of 1 kHz.
b. Enable the level ratio mod to set the flatness
reference.
c. Enter the Calibrator test frequencies and Analyzer
special functions indicated in Table 5-5 and record the
Analyzer ratio measurements.
5-25. Source Impedance Accuracy. Depress the LCL/
INIT key to initialize the instrument. Connect the HI and
LOW outputs using the balanced cable and adapters to
the Analyzer HI and LOW inputs. Perform the following
procedure.
a. Set the Model 1121A output level to 3.000 volts.
b. Depress the RATIO key to enable the ratio mode.
c. Connect the 600 ohm load across the binding post
adapter at the input of the Analyzer.
d. Note the display and calculate the output im-
pedance using the following formula and record Z
OUT
in
Table 5-6.
Z
out
= (100.6% / DISP% -1) 596.4
e. Disable the ratio mode and remove the 600 ohm
load.
f. Enter special function 76 (150 ohm output).
g. Depress the RATIO key to enable the ratio mode.
h. Connect the 150 ohm load across the binding post
adapters at the input of the Analyzer.
i. Note the display and calculate the output im-
pedance using the following formula and record Z
OUT
in
Table 5-6.
Z
out
= (100.15% / DISP% -1) 149.8
j. Disable the ratio mode and remove the 150 ohm
load.
k. Enter special function 75 (50 ohm output).
l. Depress the RATIO key to enable the ratio mode.
m. Connect the 50 ohm load across the binding post
adapters at the input of the Analyzer.
Z
out
= (100.05% / DISP% -1) 49.98
n. Note the display and calculate the output im-
pedance using the following formula and record Z
OUT
in
Table 5-6.
o. Disable the ratio mode and remove the 50 ohm
load.
5-26. Source Level Accuracy. In this test the Analyzer
level reference is set using the precision calibrator. The
accuracy of the Model 1121A is then measured at the
same test levels and compared to the measurements
using the calibrator thereby eliminating the Analyzer
measurement errors.
5-27. Depress the LCL/INIT key to initialize the instru-
ment. Enter special function 75 (50 ohm output) and
enable the input floating mode. Perform the following
procedure for each test level listed in Table 5-7.
a. Connect the 50 Hz - 50 kHz Calibrator output to
the Analyzer HI and LOW inputs using the balanced cable
and adapters.
b. Depress the Analyzer LEVEL key and enter the
Model 5100B level in the ANALYZER display window to
set and hold the input level range.
c. On the AC Calibrator enter the Model 5100B level
at a frequency of 1 kHz.
d. After the ANALYZER display settles enable the
ratio mode to set the calibrator level reference.
e. Connect the Model 1121A HI and LOW outputs to
the Analyzer HI and LOW inputs using the balanced cable
and adapters.
f. Enter the Model 1121A test level at a frequency of
1 kHz and record the measurement in the ACTUAL
column in Table 5-7.
5-28. Source Level Flatness. The level flatness test is
made using the Analyzer ratio mode where a level
reference is set at a frequency of 1 kHz and at a specific
test level. The frequency is then varied and the resultant
relative amplitude errors are measured. In this test the
Analyzer flatness is first verified using the precision AC
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