User's Manual

Doc. No.
Rev.
Date
DRAFT
1.01
2012-01-27
Damm Cellular Systems A/S, Denmark
TetraFlex
®
7.5 Manual - BS41x Configuration
TetraFlex® 7.5 Manual 2-86
The test cable must be a 50 cm long RG214 cable with two N-male connectors.
2.7.13.3 Adjustment Procedure
Step 1: Prepare the adjustment:
o Connect the PC to the BS, log-on and address a TR to be used for the adjustment.
Any TR connected to the node can be used.
o Make Local Blocking (01+)
o Select test mode CW (02/- and 15/CW)
o Check the TX output power to be set to the required value (13).
o Check, the TMA pre-gain to be 6.0dB (72)
o Key the transmitter (10+) and activate the RFTL (32+)
o Display RSSI (R/21/0)
o Turn the 3 attenuators on AI411 “GAIN A”, “GAIN-B” and RFTL “OUT” to maximum
RSSI (minimum attenuation).
Step 2: RFTL input level adjust
This step adjusts the RFTL input attenuator to give a fixed level on the RFTL mixer
independent of the selected output power:
The attenuation shall be adjusted to the following:
TR power (Tetra)
TR power (Analogue)
Attenuator
25W
50W
15dB
12W
25W
12dB
6W
12W
9dB
3W
6W
6dB
1.5W
3W
3dB
o Turn RFTL input attenuator to minimum attenuation
o Register the RSSI
o Increase attenuation until the RSSI has decreased to the value from the table
Step 3: RFTL output level adjust
This step adjusts the RFTL output level at the BS TMA Test Connector to be correct, if the
feeder loss is 8dB.
o Remove the feeder on the Test connector on top of the rack.
o Remove the feeder on the RX-A connector on top of the rack
o Connect the test cable between the Test connector and the RX-A connector.
o Adjust the RFTL out attenuator to give an RSSI of –47dBm on TR41x input.
o Remove the test cable and re-connect the feeders again
The –47dBm is related to the nominal test signal level of –105dBm at the TMA, with a
coupling loss in the TMA in forward direction of 50dB and a feeder loss of 8dB.
Step 4: Feeder loss compensation adjust
This step adjusts the RFTL output attenuator and the RM input attenuators to compensate
the feeder loss.