Keysight Technologies X Series Service Manual page 637

Functional Tests
Displayed Average Noise Level (DANL)
4. Press Restart, then wait for Average/Hold to display 20/20.
5. Press View/Display, Display, then press Display Line, On.
6. Rotate the knob and set the display line at the average amplitude of the
7. Confirm that the measurement is performed on the analyzer noise floor
Ignore the residual response if one appears when taking the measurement.
8. Enter the value of the display line as the Measured Average Noise Level at
9. Normalize the measured value to a 1 Hz BW by adding 30 dB to the
The −30 dB value is added because the formula used to calculate the value of the noise power in
a 1 Hz BW when measured with a 1 kHz BW is:
Normalized Noise = 10 Log (BW 2/BW 1) where BW 2 is the 1 kHz BW we measure and BW 1 is
1 Hz BW to which we want to normalize.
Therefore, 10 Log (1000) = 30 dB, so the noise floor will be 30 dB lower in a 1 Hz BW.
10.Enter the normalized value of the displayed average noise level in
11.The value of the normalized displayed average noise should be less than
12.Change the analyzer center frequency to the next value listed in
13.Repeat
Keysight N9010A EXA Service Guide
BW, Video BW, 100, Hz
Meas Setup, Average/Hold, Number, 20, Enter
Trace/Detector, Trace Average
Single
displayed noise floor by visual inspection.
and not on a residual response within the displayed 10 kHz span.
10 MHz column in Table
measured value.
17-1.
the specification value.
17-1. Press: FREQ Channel, Center Freq, [Table 2-1 Value], GHz
step 7 through
your analyzer frequency range.
17-1.
step 12 to fill in the remainder of
Table
Table
Table 17-1 for
637