User Guide

PAMS
Technical Documentation
WinTesla User Guide
NHD–4
Page 40
Original 11/97
Rx Gain Switch Calibration
The purpose of this tuning operation is to calibrate the gain differential of
the receiver system with the LNA on and off.
This tuning is needed if the LNA (V12), N701 or N702 is changed
Definition of Tuning
This operation determines the gain differential of the receiver system with
the LNA on and off. The CDMA receiver system is then calibrated
accordingly. To do this a constant level CW tone is fed into the CDMA
receiver. The LNA is turned on and the received signal strength to the
CDSB ASIC (D704) is read and stored. This is the also known as the
RxCtr value. With the same input signal the LNA is then turned off and
the RxCtr is read again. The dB power difference between the two RxCtr
values is equivalent to the gain that the LNA provides.
Rx Gain Switch calibration steps & equipment:
– Using the JBS–7 service jig, replace the standard battery of the phone
with the dummy battery BTS–4.
– Apply +6.0 V to dummy battery.
– Select ” Tuning – Rx Gain Switch Calibration”
– Set the signal generator as requested and press the tune Key.
– Press <save & exit> to store value to EEPROM or <close> to exit with-
out saving.