Keysight N9038A, Руководство по обслуживанию

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674 Keysight N9038A MXE Service Guide
Tests
Displayed Average Noise Level (DANL)
9. Perform the following steps for each row listed in Table 22-4 .
a. Set the receiver center frequency to the value listed in the Center
Frequency column in Table 22-4 by pressing FREQ Channel , Center
Freq , [Value].
b. On the receiver, press Restart .
c. Wait for the receiver to finish averaging.
d. On the receiver, press View/Display , Display , Display Line On .
e. Rotate the knob and set the display line at the average amplitude of
the displayed noise floor by visual inspection.
f. Confirm that the measurement is performed on the analyzer noise
floor and not on a residual response within the displayed 10 kHz
span.
g. Enter the value of the display line as the Measured Average Noise
Level in Table 22-4 .
h. Normalize the measured value to a 1 Hz BW by adding -30 dB to
the measured value.
i. Enter the Normalized Average Noise Level value in Table 22-4 .
j. The value of the normalized displayed average noise should be less
than the specification value.
Table 22-4 Displayed Average Noise Level (DANL) Results - RF Input 2
Center Frequency
Measured Average Noise Level
(dBm)
Normalized Average Noise Level
/(1 Hz BW)
(dBm)
Test Limits
(dBm)
10 MHz –139
100 MHz –140
500 MHz –142
1 GHz –140