Setting Trigger Source; Setting External Clock - JDS Uniphase CellAdvisor JD780A Series User Manual

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

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 204 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 20 External reference indicators
Type Indicator
Internal
External
External
GPS
HOLD in red disappears and the sweeping resumes.
Description
The green INT icon indicates that the instrument uses the built-in
(green)
internal time base.
The green EXT icon indicates that an external reference is connected
(green)
and locked and that the instrument uses the same reference clock as
the signal source.
The red EXT icon indicates that an external reference is connect but not
(red)
locked.
(green) The green GPS antenna icon indicates that a GPS antenna is
Using TD-SCDMA Signal Analyzer
JD780A Series Analyzers
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