User's Manual Part 2

Test Set Calibration – continued

6-70 1X SC480 BTS Hardware Installation, Optimization/ATP, and FRU MAY 2004

PRELIMINARY

3. Measure the loss of the short cable plus the TX test cable

configuration. The TX test cable configuration normally consists of

two coax cables with type–N connectors, a directional coupler, a

termination load with sufficient rating to dissipate the BTS output

power, and an additional attenuator, if required by the BTS type. The

total path loss of the TX test configuration must be as required for

the BTS (normally 30 or 50 dB). The Motorola Cybertest analyzer is

different from other communications system analyzers because the

required attenuation/load is built into the test set. Because of this,

the Cybertest TX test configuration consists only of the required

length coax cable.

Calibrating Test Cable

Configurations with a

Communications System

Analyzer

Cable Calibration is used to calibrate both TX and RX test cables.

WinLMF cable calibration cannot be accomplished with an

HP8921A analyzer for 1.9 GHz. A different analyzer type

or the signal generator and spectrum analyzer method

(Table 6-27 and Table 6-28) must be used. Cable

calibration values must be manually entered into the

WinLMF cable loss file if the signal generator and

spectrum analyzer method is used. To use the HP8921A for

manual test cable configuration calibration for 800 MHz

BTSs, refer to the Manual Cable Calibration section of

Appendix B.

NOTE

Prerequisites

S Test equipment is turned on and has warmed up for at least 60

minutes. Agilent E7495A requires only 30 minute warmup.

S Test equipment has been selected in the WinLMF (Table 6-23 or

Table 6-24).

S Test equipment has been calibrated and correctly connected for the

type of test cable configuration to be calibrated.

Calibrating cables

Refer to Figure 6-19 or Figure 6-20 and follow the procedure in

Table 6-26 to calibrate the test cable configurations.

Table 6-26: Procedure to Test Cabling Calibration using Communication System Analyzer

n Step Action

1 Click Util in the BTS menu bar, and select Cable Calibration... in the pull–down menu. A Cable

Calibration window is displayed.

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