Nortel DualMode 800, Maintenance Manual

Page: 156 / 216

11-18 DRU tests
411-2051-500 Draft 00.01 November 1999
Modulation Limiting test
Modulation Limiting is the ability of the transmitter to effectively operate
within the system deviation limits. This test ensures that the transmit
carrier deviation of the TRU meets the system specifications.
4 This step is performed at the MTX.
From the MAP position or with a second
terminal logged into the switch, test the trunk
that is assigned to the TRU being tested by
entering:
MAPCI;MTC;TRKS;TTP;POST
(CLLI name)
(Trunk member number)
;TGEN 1004 -180
MAP Trunk Test Position is displayed. The
MAP screen will indicate the trunk member
selected and that the trunk is selected.
It will also indicate the tone generated and
the level of the tone.
5 Check the carrier frequency deviation as
displayed on the DEV meter. Deviation between 2.61 kHz and 3.19 kHz.
6 Record the deviation on the test forms.
7 If the deviation is different from the site
specific Forward audio level setting, repeat
this test after all the transmit tests have been
completed. Set the deviation to the specific
operational level with the T command from
the interface terminal. The transmit audio level is shown on the
terminal screen as:
Audio Sens Tx: -18.0
(change this
level as required—a change of 1 dBm is
approximately a change of 0.27 kHz in
deviation)
8 From the interface terminal, use the R
command to turn off (mute) the TX audio.
>R
The terminal will prompt for audio path:
Enter TX, RX, BOTH or OFF
9 Enter the option “OFF”:
>OFF
The audio status on the screen shows:
Audio: off
- End -
Step Action Observation