User Manual

Test Set Calibration – continued
3-72 1X SC4812T–MC BTS Optimization/ATP 5/21/04
DRAFT
measure the loss of each cable configuration (TX cable configuration and
RX cable configuration). The cable calibration consists of the following:
S Measuring the loss of a short cable – This is required to compensate
for any measurement error of the analyzer. The short cable (used only
for the calibration process) is used in series with both the TX and RX
cable configuration when measuring. The measured loss of the short
cable is deducted from the measured loss of the TX and RX cable
configuration to determine the actual loss of the TX and RX cable
configurations. The result is then adjusted out of both the TX and RX
measurements to compensate for the measured loss.
S Measuring the short cable plus the RX cable configuration loss –
The RX cable configuration normally consists only of a coax cable
with type-N connectors that is long enough to reach from the BTS RX
port of the test equipment.
S Measuring the short cable plus the TX cable configuration loss –
The TX cable configuration normally consists of two coax cables with
type-N connectors and a directional coupler, a load, and an additional
attenuator (if required by the specified BTS). The total loss of the path
loss of the TX cable configuration must be as required for the BTS
(normally 30 or 50 dB).
Calibrate Test Cabling using
Communications System
Analyzer
Cable Calibration is used to calibrate both TX and RX test cables.
Appendix F covers the procedures for manual cable calibration.
Prerequisites
Ensure the following prerequisites have been met before proceeding:
S One of the following:
– LMF computer serial port and test equipment are connected to the
GPIB box
– For E7495A, the LMF computer network card and the E7495 are
connected to the Ethernet hub (Appendix NO TAG, Agilent
E7495A Test Equipment Setup section, Connections subsection)
S Test equipment is turned on and has warmed up for at least 60
minutes.
S Test equipment has been selected in the LMF (Table 3-24, Table 3-25,
or Table F-2)
Calibrating cables
Refer to Figure 3-13 or Figure 3-14 and follow the procedure in
Table 3-27 to calibrate the test cable configurations.
Table 3-27: Cable Calibration
n Step Action
1 From the Util menu, select Cable Calibration. A Cable
Calibration window is displayed.
3