User's Manual

Test Set Calibration
68P09255A69-3
Aug 2002
1X SC4812ET Lite BTS Optimization/ATP Software Release 2.16.1.x
PRELIMINARY
3-70
2. Measure the loss of the short cable plus the RX test cable
configuration. The RX test cable configuration normally consists
only of a coax cable with type-N connectors that is long enough to
reach from the BTS RX connector to the test equipment. When the
BTS antenna connectors carry duplexed TX and RX signals, a
directional coupler and, if required by BTS type, an additional
attenuator are also required for the RX test cable configuration.
These additional items must be included in the path loss
measurement.
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
NOTE
LMF cable calibration cannot be accomplished with an
HP8921A analyzer for 1.9 MHz. A different analyzer type or the
signal generator and spectrum analyzer method (Table 3-32 and
Table 3-33) must be used. Cable calibration values must be
manually entered into the LMF 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 F.
Prerequisites
Test equipment is turned on and has warmed up for at least 60
minutes.
Test equipment has been selected in the LMF (Table 3-28 or
Table 3-29).
Test equipment has been calibrated and correctly connected for the
type of test cable configuration to be calibrated.
Refer to Figure 3-10 or Figure 3-11 and follow the procedure in
Table 3-31 to calibrate the test cable configurations.
Table 3-31: Test Cable Configuration Calibration with a Communications System Analyzer
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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