HP 54520 Series Service Manual page 61

10
10
aon
i»
7)
To test trigger sensitivity
Adjust the trigger level for a stable display.
The test passes if triggering is stable. Record the result in the Performance Test
Record.
Set the signal generator frequency to 500 MHz and output level to 64 mVrms
(180 mVp-p from the generator, 90 mVp-p into the trigger).
Adjust the trigger level for a stable display.
The test passes if triggering is stable. Record the result in the Performance Test
Record.
Auxiliary Trigger Test
The auxiliary trigger input is on the rear panel of the oscilloscope. The input impedance of
the aux trigger is 4 kQ so, to avoid reflections, the test is done without other terminations.
With an N-to-BNC adapter and BNC cable, connect the signal generator to the
channel 1 input.
Set the signal generator for 50 MHz .
Set the channel 1 input to 1 MQ (50 Qis not lit) and press autoscale .
Set the channel | sensitivity to 50 mv/div and set the signal generator for 5
divisions of signal, 250 mVp-p.
Disconnect the signal cable from the channel 1 input and connect it to the Aux
trigger input on the rear panel.
Press the Trigger setup andset the source to Auxiliary.
Set the trigger level to 0.000 V. Only running should appear in the status in the
upper left corner of the display.
If the status is running-auto triggering or running-awaiting trigger, the
oscilloscope is not triggered.
The test passes if the oscilloscope triggers. Record the result in the Performance
Test Record.
If a test fails
Failure of the internal trigger or external trigger sensitivity tests can be caused by a defective
main assembly or attenuator. Failure of the auxiliary trigger sensitivity is caused by a problem on
the main assembly or a bad input cable. If you need further troubleshooting information, go to
chapter 5, "Troubleshooting."
3-17