5-27
Servicing
Performance Tests
3Turn the Agilent 83430A on, and press both front-panel PRESET/VARIABLE
buttons so that the WAVELENGTH ADJUST and BIAS ADJUST lights are off.
4On the Agilent 83480A digital communications analyzer, adjust the am plitude
scale, time scale, and offsets as needed.
5Adjust the Agilent 83430A’s front-panel DIGITAL THRESHOLD knob so that a zero
crossing occurs at center screen (approximate 50% crossing).
6On the Agilent 83480A, perform the following step s:
aTurn the optical channel on. Turn all other channels off.
bEnable the internal OC-48 filter.
cPress the blue shift key and then press MEAS EYE.
dPress Extinction ratio.
ePress Continue to activate the color grade.
fPress Dark cal, and follow the instructions on the screen.
gWhen the dark calibration is complete, press Format to select decibels.
hPress Enter to complete the measurement setup.
7Clear the Agilent 83480A’s display, and allow adequate time for the extinction
ratio measurement to settle.
8The extinction ratio should measure greater than 9.0 dB.
9On the Agilent 83480A, set the persistence to 1s and turn off the color grade.
10 Press the blue shift key and then press MASK TEST.
11 Press Mask Test On.
12 Press Create Mask and then Standard. Select the OC-48 mask.
13 Press Done.
14 Set the mask margin to 10%.
15 Press Mask Align to center the mask on the eye.
Repeat this step as needed if the vertical dashed lines do not occur at the cross-
ing waist on either side of the eye.
16 Press Run Until, and wait for 300 waveforms to be processed.
17 Press the blue shift key and then press Eye mask to display the eye mask results.
Verify that there are no mask or margin hits.