JDS Uniphase CellAdvisor JD780A Series, User Manual

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JD780A Series Analyzers
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Using CDMA Signal Analyzer
hold the measurement or get a single sweep, you can change the sweep mode.
Procedure
To select the single sweep mode:
1.
Press the SWEEP hot key.
2.
Toggle the Sweep Mode soft key and select Single . You can also use the HOLD hot key.
The letter HOLD in red appears and the sweeping is paused.
3.
Optional . Press the Sweep Once soft key to get a new measurement.
To return to the continuous sweep mode:
1.
Toggle the Sweep Mode soft key and select Continue . You can also use the HOLD hot key.
The letter HOLD in red disappears and the sweeping resumes.
Setting trigger source
You can set the trigger source option for your measurements. Connecting an external trigger is
necessary for accurate modulation measurements on CDMA systems.
Procedure
1.
Press the TRIGGER hot key.
2.
Select the trigger source option from the following choices: Internal , External , or GPS .
Setting external clock
To enhance the reliability of modulation analysis measurements the JD780A series must be
synchronized with a base station. When an external clock is not supplied, the instrument works with its
built-in internal high-accuracy time base and some measurement results may exhibit inaccurate values.
Therefore, it is highly recommended that you use the same reference clock as the signal source. You
can use the
TRIGGER hot key to set the external clock.
Table 16 Standards of external clock operation
Clock Type Reference Port Switching Standard
External Reference Internal Internal 10 MHz Default
External External Ref Clock Ext Ref (SMA) Manual switching
(Input signal level >-3 dBm)
GPS GPS Clock GPS (SMA) Automatic switching
(GPS signal received)
Trigger Internal Internal Trigger Default
External External Trigger Trigger (SMA) Manual switching
GPS GPS GPS (SMA) Manual switching