Chapter 2
GSM Call Mode Operation
GSM tests
84
4460 GSM System Option and 4468 EDGE System Option
Version 12.20
Softkeys of the ACPM transient spectrum menu
Display markers
The 4400 offers two markers for easy reading of the graphic spectrum displays:
Modulation spectrum measurement
On the kHz entry fields, you set the markers to the required horizontal positions
(= offset from the carrier in kHz).
The corresponding result fields (
dBm
) show the measurement values obtained for
the two positions in dBm.
The third row shows the difference between the selected frequencies and the
difference between the two corresponding measurement values.
A push on this softkey starts the peak-hold process of the
“ACPM transient spectrum measurements”
.
When the peak-hold process is running, the softkey will
change to
|Stop Peak|
.
A push on this softkey stops the peak-hold process of the
“ACPM transient spectrum measurements”
and takes you
back to the continuous measurement.
The softkey will change to
|Start Peak|
.
To freeze the current display for further or detailed analysis
(or for printing), push this softkey.
The softkey will change to
|Unfreeze|
.
Note:
After the
|Freeze|
softkey has been pushed, all mea-
surements (and any ongoing peak-hold process) continue in
the background, but the display is not updated.
This means that even when the live display has been frozen, a
reset of the peak-hold process is possible, pushing the
|Reset|
softkey.
To unfreeze the current display, push this softkey.
The softkey will change to
|Freeze|
.
A push on this softkey resets the peak-hold process of the
“ACPM transient spectrum measurements”
.