User's Manual Part 2

Test Set Calibration – continued
MAY 2004 1X SC480 BTS Hardware Installation, Optimization/ATP, and FRU 6-73
PRELIMINARY
Figure 6-22: Cal Setup for Non–Duplexed RX Test Cabling Using Signal Generator & Spectrum Analyzer
Spectrum
Analyzer
Signal
Generator
A
B
Spectrum
Analyzer
SHORT
TEST
CABLE
CONNECTION TO THE COMMUNICATIONS
SYSTEM ANALYZER RF OUTPUT
CONNECTOR DURING RX MEASUREMENTS
Signal
Generator
BULLET
CONNECTOR
TX test
cable
SHORT TEST
CABLE
CONNECTION TO THE BTS RX ANTENNA
CONNECTOR DURING RX ATP
IMPORTANT: IF BTS TX/RX SIGNALS ARE
DUPLEXED, THE RX TEST CABLE CONNECTS
TO THE DUPLEXED ANTENNA CONNECTOR
AND MUST USE/BE CALIBRATED WITH THE 30
DB DIRECTIONAL COUPLER AND 20 DB
IN–LINE ATTENUATOR. SEE FIGURE 6-21.
Setting Cable Loss Values
Cable loss values for TX and RX test cable configurations are normally
set by accomplishing automatic cable calibration using the WinLMF and
the applicable test equipment. The WinLMF stores the measured loss
values in the cable loss files. The cable loss values can also be set or
changed manually. Follow the procedure in Table 6-29 to set cable loss
values.
CAUTION
If cable calibration was performed without using the WinLMF,
cable loss values must be manually entered in the WinLMF
database. Failure to do this will result in inaccurate BTS
calibration and reduced site performance.
Prerequisites
S WinLMF is logged into the BTS
Table 6-29: Procedure for Setting Cable Loss Values
Step Action
1 Click Util in the BTS menu bar, and select Edit > Cable Loss in the pull–down menus.
–A tabbed data entry pop–up window will appear.
2 Click on the TX Cable Loss tab or the RX Cable Loss tab, as required.
3 To add a new channel number, perform the following:
3a – Click on the Add Row button.
3b – Click in the Channel # or Loss (dBm) column, as required.
3c – Enter the desired value.
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