User Manual

AS4000 Operations and Maintenance
Section
605-0000-431
6
. Issue 1.6. Date3/2/99
DLP-013
Page 5 of 60 © Copyright Airspan Communications Corporation 1999
POWER
METER
CT
15W
Termination
RF Power meter
connection when
measuring Modem
Shelves 1 & 2
TX Output Power
DIP/LNA1 TX Filter
15W
Termination
POWER
METER
CT
RF Power meter
connection when
measuring Modem
Shelves 3 & 4
TX Output Power
DIP/LNA1 TX Filter
Figure 7-1. Power Level measurement Test Set-up
1. Restore power to the rack.
2. The TX output power level 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 rate
acquisition mode. Two users provide an output of 24 ± 0.5dBm.
3. 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 the Site Controller/ 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. See Figure 7-7.
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 ± 0.5dBm.
c) Record results
d) Switch off rack. by placing both breakers in the off position.
Ensure that the power Output is at steady level before setting up the RX gain control.