JDS Uniphase CellAdvisor JD780A Series, User Manual

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JD780A Series Analyzers
Using CDMA Signal Analyzer
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Pre-amplifier
You can turn the internal pre-amplifier on to correct and compensate for the gain of the preamp so that
amplitude readings show the value at the input connector.
Procedure
1.
Press the AMP/SCALE hard key.
2.
Toggle the Preamp soft key and select On or Off as needed.
NOTE
You can turn the Preamp on when the input attenuation range is from 0 dB to 10 dB. If
the attenuation value is manually set to greater than 10 dB, the instrument will
automatically turn off the pre-amplifier to display low-level signal properly on the chart.
External offset
You can turn the External Offset on and manually set the external offset value. An offset consists of a
cable loss and a user offset and the measurement result shows the value reflecting both offset values.
When the external offset value is set at 40 dB in the Spectrum mode, the measurement result
compensates 40 dB at both the Spectrum Analyzer and Signal Analyzer modes
Procedure
To set the external offset:
1.
Press the AMP/SCALE hard key.
2.
Toggle the External Offset soft key and select On .
3.
Enter a value by using the numeric keys.
4.
Press the dB soft key to complete the entry.
To turn the external offset off:
1.
Press the AMP/SCALE hard key.
2.
Toggle the External Offset soft key and select Off .
Setting average
You can set the number of measurements to be averaged for the trace presentation. A maximum of
100 times of averaging can be set. When the averaging reaches to your setting, a new measurement
value replaces the measurement value in sequence from the earliest.
Procedure
1.
Press the BW/AVG hard key.
2.
Press the Average soft key.
3.
Enter a value between 1 and 100 as needed by using the numeric keys.
4.
Press the Enter soft key.
Setting sweep mode
The default setting is Continue to sweep continuously for most on-going measurements. If you want to