JDS Uniphase CellAdvisor JD780A Series, Руководство пользователя

Страница: 61 / 592

JD780A Series Analyzers
Using Spectrum Analyzer
61
b. Select the span option, from the following choices:
–
To set the span manually, select Span , enter a value, and then select the unit.
–
To set the span automatically, select Full Span , Zero Span , or Last Span as needed.
NOTE
The Zero Span option is available only in the Spectrum mode. If you have selected Zero
Span , select TRIGGER > Free Run , External , GPS , Video , or Display Position .
Optional . To define the amount of frequency increment for the rotary knob:
1.
Press the Frequency Step soft key, if the Freq is selected.
2.
Enter a value by using the numeric keys.
3.
Press the unit: GHz , MHz , kHz , or Hz .
Optional . To define the amount of channel increment for the rotary knob:
1.
Press the Channel Step soft key, if the Channel is selected.
2.
Enter a value by using the numeric keys.
3.
Press the Enter soft key.
NOTE
This setting is not used in the Spurious Emissions mode.
Setting amplitude
Reference level and attenuation
You can set the reference and attenuation levels automatically or manually to optimize the display of
the traces measured, as you desire.
Procedure
To automatically set the reference and attenuation level:
1.
Press the AMP/SCALE hard key.
2.
Press the Auto Scale soft key.
Each time you press this key, both of the Y-axis scale and input attenuation level change to be
optimized with some margin.
To set the reference or attenuation level manually:
1.
Press the AMP/SCALE hard key.
2.
To set the maximum reference level on the Y-axis manually, complete the following steps:
a. Press the Reference Level soft key.
b. Enter a value by using the numeric keys or the rotary knob with 10 dB increments.
c. Press the unit soft key or the ENTER hard key.
3.
To set the attenuation option, select one from the following choices:
–
To set the input attenuator
’s level automatically, select
Attenuation > Auto .
NOTE
It is recommended that you set the Attenuation to Auto in most situations so that the
level of the input attenuator can be set automatically according to your input signal level.
–
To set the input attenuation manually up to 55 dB to optimize S/N, complete the following