5-18
Servicing
Performance Tests
generator” on page 5-35.
data pattern. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223–1
data amplitude (ECL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .850 mV p-p
data output high level (ECL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –900 mV
data termination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .–2 V
trigger mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .CLOCK / 23
trigger pattern. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 zeros
clock rate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.48832 GHz
clock amplitude. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 850 mV
3Press the Agilent83430A’s front-panel SELECT key repeatedly until the ANALOG
IN AC COUPLED light is on.
4On the Agilent83480A digital communications analyzer, perform the following
tasks:
aTurn the optical channel on. All other channels should be turned off.
bEnable the internal OC-48 filter.
5Connect the Agilent 83430A to the optical channel.
6Disconnect the modulation input cable from the ANALOG IN AC COUPLED
connector.
7On the Agilent 83480A, position voltage cursor 1 to the displayed unmodulated
level.
8Turn the Agilent83430A’s LINE switch off.
9On the Agilent 83480A, position voltage cursor 2 to the display ed dark level
voltage. Do not disconnect the fiber-optic cable until the 80% modul ation index
is measured.
10 Measure the voltage difference between the two cursors, multiply this value by
0.8, and position cursor 2 to where the difference equals this calculated value.
11 Turn the Agilent83430A’s LINE switch on.
12 Reconnect the modulation input cable to the ANALOG IN AC COUPLED connector.
13 Increase the pattern generator’s data amplitude until the average (lower ) peak
of the eye reaches the level indicated by voltage cursor 2.
14 The data amplitude shown on the pattern generator’s display should be
between 1.05 V p-p and 1.9 V p-p.
15 Connect the equipment as shown in the following figure.