JDS Uniphase CellAdvisor JD780A Series, Руководство пользователя

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JD780A Series Analyzers
460
Using Mobile WiMAX Signal Analyzer
Setting trigger source
You can set the trigger source option for your measurements.
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.
Figure 229 Connection ports for external reference clock
Procedure
1.
Connect an external reference or a GPS antenna to the JD780A series.
2.
Press the SYSTEM hot key.
3.
Press the Freq Reference soft key, and then select the reference option: Internal , External 10
MHz , External 13 MHz , External 15 MHz , or GPS .
Table 21 External reference indicators
Type Indicator Description
Internal
(green)
The green INT icon indicates that the instrument uses the built-in
internal time base.
External
(green)
The green EXT icon indicates that an external reference is connected
and locked and that the instrument uses the same reference clock as
the signal source.
External
(red)
The red EXT icon indicates that an external reference is connect but not
locked.
GPS (green) The green GPS antenna icon indicates that a GPS antenna is
connected and locked.
GPS (yellow) The yellow GPS antenna icon indicates that a GPS antenna is
connected and locking is in progress.
GPS (grey) The grey GPS antenna icon indicates that a GPS antenna is not
connected, failed, or unable to be locked.