Chapter 11
Using EV-DO Signal Analyzer
JD700B Series User’s Guide
391
Couple
.
As you increase the reference setting, the attenuation level also increases acoordingly.
Optional
.
To change the scale unit:
1
Select
More (1/2) > Units
.
2
Select the unit of the display scale:
dBm
,
dBV
,
dBmV
,
dBµV
,
V
, or
W
.
The scale unit on the screen changes accordingly.
NOTE
This Units menu is available in the Spectrum and RF Analysis modes.
Scale per division
You can use the
Scale/Div
feature available for the spectrum and RF analysis. It represents the value of one
division on the horizontal scale. The default setting is 10 dB per division and the maximum value can be set
up to 20 dB.
Procedure
To set the scale per division:
1
Press the
AMP/SCALE
hard key.
2
Select
More (1/2) > Scale/Div
.
3
Enter a value between 1 and 20 by using the numeric keys.
4
Press the
dB
soft key to complete the entry.
Pre-amplifier
You can turn the internal pre-amplifier on to correct and compensate for the gain of the preamp so that
amplitude readings show the value at the input connector.
Procedure
1
Press the
AMP/SCALE
hard key.
2
Toggle the
Preamp
soft key and select
On
or
Off
as needed.
NOTE
You can turn the Preamp on when the input attenuation range is from 0 dB to 10 dB. If
the attenuation value is manually set to greater than 10 dB, the instrument will
automatically turn off the pre-amplifier to display low-level signal properly on the chart.
External offset
You can turn the
External Offset
on and manually set the external offset value. An offset consists of a cable
loss and a user offset and the measurement result shows the value reflecting both offset values. When the
external offset value is set at 40 dB in the Spectrum mode, the measurement result compensates 40 dB at
both the Spectrum Analyzer and Signal Analyzer modes.
Procedure
To set the external offset:
1
Press the
AMP/SCALE
hard key.
2
Toggle the
External Offset
soft key and select
On
.
3
Enter a value by using the numeric keys.
4
Press the
dB
soft key to complete the entry.