Chapter 8
Using LTE-FDD Signal Analyzer
218
JD700B Series User’s Guide
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.
Procedure
1
Press the
TRIGGER
hot key.
2
Select the trigger source option from the choices:
Internal
,
External
, and
GPS
.
Setting external clock
To enhance the reliability of modulation analysis measurements the JD700B 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 114 Connection ports for external reference clock
Procedure
1
Connect an external reference or a GPS antenna to the JD700B series.
2
Press the
SYSTEM
hot key.
3
Press the
Freq Reference
soft key, and then select the reference option from the choices:
Internal
,
External 10 MHz
,
External 13 MHz
,
External 15 MHz
, and
GPS
.
Table 13
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.
