User's Manual Part 2

ManualsBrandsNokia Solutions and Networks ManualsElectronics1X SC480 BTS Microcell Base Station Transmitter

Test Set Calibration – continued

6-72 1X SC480 BTS Hardware Installation, Optimization/ATP, and FRU MAY 2004

PRELIMINARY

Figure 6-21: Cal Setup for TX/Duplexed RX Test Cabling

Using Signal Generator & Spectrum Analyzer

50 OHM

TERMINATION

30 DB

DIRECTIONAL

COUPLER

Spectrum

Analyzer

Signal

Generator

Spectrum

Analyzer

40W NON–RADIATING

RF LOAD

SHORT TEST CABLE

Signal

Generator

THIS WILL CONNECT TO THE POWER METER OR COMMUNICATIONS

SYSTEM ANALYZER DURING TX CALIBRATION AND TO THE

COMMUNICATIONS SYSTEM ANALYZER DURING TX AND RX ATP TESTS.

SHORT

TEST

CABLE

20DB 20 W IN–LINE

ATTENUATOR FOR

1.9 GHZ

THIS WILL CONNECT TO THE BTS TX

ANTENNA CONNECTOR DURING TX

CALIBRATION AND TO THE TX/RX ANTENNA

CONNECTORS DURING ATP TESTS.

TX TEST

CABLE

RX TEST CABLE FOR RX ATP TEST

SECOND TX TEST CABLE FOR TX CAL AND ATP

Table 6-28: Procedure for Calibrating Non–Duplexed RX Test Cabling Using

Signal Generator & Spectrum Analyzer

Step Action

NOTE

When preparing to calibrate a BTS with Duplexed TX and RX the RX cable calibration must be done

using calibration setup in Figure 6-21 and the procedure in Table 6-27.

1 Connect a short test cable between the spectrum analyzer and the signal generator as shown in

Figure 6-22, detail “A” (top portion of figure).

2 Set signal generator to –10 dBm at the customer’s RX frequency of:

824–849 for North American Cellular or 1850–1910 MHz band for North American PCS

3 Use spectrum analyzer to measure signal generator output (see Figure 6-22, A) and record the value.

4 Connect the test setup, as shown in the lower portion of the diagram (see Figure 6-22, B) to measure

the output at the customer’s RX frequency of:

824–849 for North American Cellular or 1850–1910 MHz band for North American PCS

Record the value at point B.

Calibration factor = (value measured with detail “A” setup) – (value measured with detail “B” setup)

Example: Cal factor = –12 dBm – (–14 dBm) = 2 dB

NOTE

The short test cable is used for test equipment setup calibration only. It is not part of the final test

setup. After calibration is completed, do not re-arrange any cables. Use the test cable configuration

as–is to ensure test procedures use the correct calibration factor.