User Manual

AS4000 Operations and Maintenance
Section
605-0000-431
6
. Issue 1.6. Date3/2/99
DLP-014
Page 14 of 60 © Copyright Airspan Communications Corporation 1999
Ensure that the power Output is at steady level before setting up the RX gain control
Move quickly to the next test to minimise down time of existing circuits.
7. RX Sensitivity
The purpose of this test is to enable the RX sensitivity to be set to -98dBm to within 1dB.
This section provides details of the test set-up for the setting of the RX gain control.
a) Switch rack off by placing both breakers in the off position.
b) Disconnect terminations on DIP/LNA1 and TX filter.
c) Connect the cables and accessories to the CT rack for Modem Shelf setting up and
functionality testing as detailed below. Set the 0-11dB variable attenuator to a nominal
5dB (the insertion loss of the test circuit should be 106dB between point A and B.
Note: If the TX Filter is fitted terminate the TX 3/4 as shown in Figure 7-11.
d) Switch the power back on at the breakers.
Power
Meter
ST
Test
Unit
(X Band)
CT Rack
3
1 2
30dB
30dB
30dB 30dB
2:1
Splitter
2:1
Splitter
2:1
Splitter
SMA-N
RF Sensor
N-SMA
11dB
Variable *
Termination
DIP/LNA TX Filter
* Set variable attenuator to give an insertion loss of 106dB
between points A and B (nominal value of 5dB)
NTU NTU
ACPSU
If TX Filter not fitted
Terminate port here
Adapter
Female to
Female
A
B
C
Figure 7-11. Test Set-Up Modem Shelves (3.4-3.6GHz Band)
8. Setting Of RX Gain Control.
a) Connect the drop cable of the CRU and the telephony VF pairs to the AC PSU.