Nokia NSB-7 Series Service Manual page 210

NSB-7
Service Software Instructions
Tuning Steps
1. Coupler Module RA5 Attenuation Measurements
Every coupler has its own individual attenuation values in different channels and there-
fore it is important to use accurate attenuation values to ensure the reliable results of
tuning and testing.
Coupler module RA5 has to be calibrated in next cases:
• When coupler is taking into use the first time
• When RF cable or attenuator is changed
Calibration should be done once a week and has been recommended to calibrate coupler
always when module is removed from JBU-6 service box and placed back.
Pay attention to the following instructions in calibration:
• Keep JBU-6 box in the same place on the table during measurements
• Close the cover of JBU-6 box carefully
• Do not touch to JBU-6 box during measurements
• Take care that cables aren't lying above cover
Calibration procedure step by step:
1 Insert coupler module RA5 to its place properly.
2 Connect cables for JBU-6 box and measuring devices carefully. Check that DC
SUPPLY MODE has been switched to FLA-5 in JBU-6.
3 Insert golden phone in the JBU-6 box.
4 Adjust DC power supply voltage to 9V. Switch power on.
5 Close the cover of the JBU-6 box and start WinTesla.
• Choose "Product" -> "open" -> "NSB-7" -> "OK"
In the case of RX calibration:
• Choose from Menu bar "Testing" and then "RF controls"
• Ensure that settings are as follows:
Page 104 ãNokia Mobile Phones Ltd.
PAMS Technical Documentation
Issue 1 06/00