Chapter 4
Using Spectrum Analyzer
106
JD700B Series User’s Guide
2
To set the maximum reference value on the Y-axis manually, compete the following steps:
Press the
Reference Level
soft key.
Enter a value by using the numeric keys or the rotary knob with 10 dB increments.
Select the unit:
dBM
or
-dBM
, or press 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
.
To set the input attenuation manually up to 55 dB for JD780 series or 50 dB for JD740B
series to optimize S/N, complete the following steps:
Select
Attenuation > Manual
.
Press the
Attenuation Value
soft key to set the level.
Enter a value in fives by using the numeric keys.
Press the
dB
soft key or the
ENTER
hard key.
To couple the input attenuator's level with your reference level setting, select
Attenuation >
Couple.
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.
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.
Procedure
To set the external offset:
1
Press the
AMP/SCALE
hard key.
2
Press the
External Offset
soft key and select
On
.
Enter a value by using the numeric keys between -120 to 120. You can also use the rotary knob
or the arrow keys.
3
Press the
dB
soft key or the
ENTER
hard key.
To turn the external offset off:
1
Press the
AMP/SCALE
hard key.
2
Press the
External Offset
soft key and select
Off
.
Содержание CellAdvisor JD700B Series
Страница 2: ...CellAdvisorTM JD700B Series FW3 120 User s Guide ...
Страница 105: ...Chapter 4 Using Spectrum Analyzer 104 JD700B Series User s Guide Figure 44 PIM detection for multiple carriers ...
Страница 406: ...Chapter 11 Using EV DO Signal Analyzer JD700B Series User s Guide 405 3 Pilot 4 MAC 64 5 MAC 128 ...
Страница 734: ...Chapter 18 Perfroming BBU Emulation JD700B Series User s Guide 733 Figure 441 Example of verification of link status ...
Страница 763: ...Chapter 21 Performing Fiber Inspection 762 JD700B Series User s Guide Figure 461 Fiber inspection report ...
Страница 808: ...Appendix JD700B Series User s Guide 807 JD740B series ...
Страница 811: ...Appendix 810 JD700B Series User s Guide Figure 470 Append keywords window ...