User Manual

AS4000 Release3 and Release 4 Central
Terminal Installation and Commissioning
DLP-013
605-0000-432
Issue 1.3a Date 18th October 1999
Page 2 of 2
4. Insert one modem card into the position 1 of the modem shelf under test.
The single user output power is 21dBm (2.0-2.3GHz and 2.3-2.5GHz Band)
The TX output power is maintained by a power control loop in the system. For the
power loop to work the CT RF card needs to generate greater than +21.75dBm,
this condition can be achieved by using Sitespan to set two users in service without
any STs in operation. This forces the two modems ( i.e. one modem card) to stay
in the high power acquisition mode. Two users provide an output of 24 ± 1.0dBm.
Measured Value will be 23.5 ± 1.0dBm (0.5dB Coupler Loss).
5. For the CT to reach it’s nominal output power from zero using the control loop
would take a considerable length of time. To bypass this process, the power
control loop may be overridden using Sitespan to set the TX power the control
voltage. Proceed as follows:
a) Using the Sitespan select the RF Card view from the Shelf view.
b) Set the transmitter volts to 2.2 volts by using the Up/Down button. Observe
that the auto levelling sets the output power to 24 ± 1.0dBm. This is actually
measured with a power meter at the antenna output port of the 80dB coupler
connected to the DIP/LNA and hence the measured power limit is 23.5 ± 1.0
dBm due to the insertion loss of the coupler.
c) Record the test result on the test form.
This Test should be repeated for the output of the TX filter if fitted.
Re connect Antenna(S) to the couplers.
Return to DLP-010 and continue the commissioning process