User Guide

PAMS Technical Documentation 6 - Troubleshooting
NPE-4
Original ãNokia Corporation. Page 6-45
The setup should now look like this:
Now it is possible to measure frequency of 3769.6MHz at the output of the VCO (G630)
using a resistive probe and a spectrum analyzer.
If this is not the case, then go to fault finding chart for PLL synthesiser in this document
for troubleshooting.
26 MHz reference oscillator ( VCTCXO )
The 26 MHz oscillator (G740) has three functions.
= Reference frequency for the PLL synthesiser.
= System clock for BB (13 MHz) after it is divided by 2 in HAGAR.
= 26 MHz Reference clock for Bluetooth Module (V130).
26 MHz signal from the VCTCXO is approx. 0,8 Vpp. Frequency of this oscillator is
adjusted by dc voltage (Vcon) coming from the DAC in UEM (D200). Range of Vcon is 0.3
– 2.3 V.