Rx Vhf Lo - Nokia RH-66 Troubleshooting Manual

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Table 11: UHF Synthesizer Test Point Values and Descriptions (Continued)
Test
Description
Point
4 Lock voltage
5 BAND_SEL_VCO
6 UHF LO:
PCS_CEL_LO return to N7160
PCS_CEL_LO return to UHF PLL
7

Rx VHF LO

The Rx VHF LO operates at a fixed frequency of 256.2 MHz. It is the second LO for down-
conversion to I and Q for baseband processing. Use the following guidelines when
troubleshooting:
• Monitor the probing point at C7101 for the N7100 LO. A locked and stable
256.2 MHz with an amplitude of ~ –60 dBm should be observed on the spectrum
analyzer (~ -2 dBm at C7104 if using a high impedance probe).
• Monitor the control voltage at C7100. The control voltage in a locked state
should be between 1.2 and 1.7 VDV for the proper operation of the N7100 LO.
Issue 1 03/2005
©2005 Nokia Corporation
2115i/2116/2116i (RH-66)
RF Description and Troubleshooting
Values
DC between 0.8 and 3.4 V, S/B 1.2 V at
center frequency
Cell = 0 VDC
PCS = 2.8 VDC
Cell: -11 dBm
PCS: -18 dBm
Cell channel 384: 1009.62 MHz > -9 dBm
PCS channel 600: 2088.10 MHz > -16 dBm
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