Chapter 6
Tools
Audio measurements
4460 GSM System Option and 4468 EDGE System Option
Version 12.20
245
Signal Source —
This selection field allows to select the signal to be fed into the
AF basic analyzer.
Selections possible are:
AF in
,
AUX in
and
Codec out
.
AF in
means that the signal connected on the
“AF in”
socket will be analyzed.
AUX in
will analyze the signal connected to the
“AUX 4 (AUX in)”
connector.
The setting
Codec out
finally will forward the audio signal decoded by the
4400 internal codec to the AF basic analyzer.
AF spectrum analyzer
The AF spectrum analyzer is a useful tool for detecting spurious signals and
harmonics. Signals from the following sources may be displayed on the spectrum
analyzer:
–
“AF in”
connector,
–
“AUX 4 (AUX in)”
connector,
–
Codec out
, the output signal of the internal codec.
The AF spectrum analyzer
menu
The menu of the AF spectrum analyzer provides a graphical display of the input
signal’s spectrum. To gain access to this menu, push the
[Spectr.
Analyzer]
marker tab.
It consists of four areas:
– Most of the menu is occupied by the
spectrum display
.
NOTE
Codec out
cannot be selected unless a call setup has been performed.
NOTE
Codec out
cannot be AF analyzer source and signal destination at the same
time. If the selection field does not allow to select
Codec out
, first de-select
Codec in
as the signal destination of the
“Audio frequency generator”
.