Agilent Technologies 54641A, Service Manual, Page: 63 / 124

3-19
Testing Performance
To verify trigger sensitivity
Test External Trigger Sensitivity
Verify the external trigger sensitivity at these settings:
500 MHz (54642A/42D), <200 mV
p-p
350 MHz (54641A/41D), <200 mV
p-p
100 MHz (All models), <100 mV
p-p
1
Use the power splitter to connect the calibrator to both the channel 1
input and the external trigger input. The Ext Trigger input is on the rear
panel of the mixed-signal oscilloscope.
2
Set up the oscilloscope.
a
Set channel 1 Coupling to DC and Imped to 50 Ohm .
b
Press the Mode/Coupling key and set Coupling to DC
c
In the
Mode/Coupling
menu, press the
External
softkey, then press the
Imped
softkey and set impedance to 50 Ohm .
3
Change the output of the calibrator to 500 MHz for the 54642A/42D or
350 MHz for the 54641A/41D, and set the amplitude to 400 mV
p-p
.
The power splitter divides the 400 mV
p-p
so that 200 mV
p-p
is applied to each
of the oscilloscope inputs.
4
Press the
Autoscale
key.
5
Press the Trigger
Edge
key, then press the
Ext
softkey to set the trigger
source to external trigger.
6
Check for stable triggering, and adjust the trigger level if necessary.
7
Record the results as Pass or Fail in the Performance Test Record.
If the test fails, see the “Troubleshooting” chapter. Then return here.
8
Change the output of the calibrator to 100 MHz and set the amplitude
to 100 mV
p-p
.
9
Check for stable triggering, and adjust the trigger level if necessary.
10
Record the results as Pass or Fail in the Performance Test Record.
If the test fails, see the “Troubleshooting” chapter. Then return here.
service.book Page 19 Wednesday, August 28, 2002 3:25 PM