Modulation Quality; Constellation Display - Wavetek IS-136 MS Operating Instructions Manual

IS-136 MS

Modulation Quality

WHY?
Requirement

Constellation display

HOW?
10-34
Test the modulation characteristics of the mobile. For
this the test set offers fast visual judgement of modula-
tion quality with the constellation display (graphic pres-
entation of modulation parameters) plus comprehensive
indication of the measured figures on the numeric dis-
play (with peak-hold function).
Make the general test preparations. The channel type
must be To digital TC. Set time alignment to a value
smaller than 26 (in other case no measurement results).
Initiate a call with
{MOBILE}
in a digital traffic channel).
This is also possible in test mode of the mobile.
Press in the basic test mask.
{CONST}
Select DISPLAY MODE in the scroll field (Fig. 10.20):
D = dots, L = lines, S = statistics (see box on page 10-37).
Press . The display shows the test results.
{RUN}
Press .
{STOP}
Change the output power of the mobile in the POWER
LEVEL scroll field. Confirm this by pressing
Press . The display shows the new test results.
{RUN}
End the test with
{STOP}
the numeric display or
mask.
Fig. 10.20: Constellation display after start-
ing test with
you that cable attenuation of test setup is
compensated (see "General Preparations").
This only affects absolute Power figure, not
other (relative) power figures like ∆P/Sym-
bol.
Modulation Quality
or (the mobile must be
{CELL.}
. After this
{NUMERIC}
back to the basic test
{RETURN}
. ATT in mask header tells
{RUN}
.
{POW_CHG}
takes you to