Nokia RM-11 Series - Tx VHF Schematic

CC Technical Documentation Troubleshooting - RF
RM-11
Issue 2 09/2005 ©2005 Nokia Corporation Confidential Page 39
Tx VHF Schematic
• There are two fixed LOs — 346.2MHz for Cell band and 416.2MHz for PCS band.
This is the first LO for up-conversion. Refer to frequency plan.
• Monitor probing point at C638 with a high-impedance RF probe for N601 LO. A
sufficiently strong and stable signal should be observed on the spectrum
analyzer.
• Monitor control voltage at C632. At this control voltage, the N601 LO is locked (it
should be between 1.2 and 1.8VDC).
Lock voltage
Loop filter
Resonator
N601