Vctcxo Manual Tuning - Nokia 2255 Manual

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VCTCXO Manual Tuning

1. The VCTCXO can be manually tuned to verify failed tuned phones, or to verify if a
phone cannot make a call. This can be done with the phone in Local Mode and
generating a CW signal. The frequency accuracy of the VCTCXO can be measured
using an HP8960 callbox in AMPS mode, an HP4406 Tx tester, or a spectrum
analyzer (preferably using a lab system 10MHz source as equipment reference).
Replace the VCTCXO if the VCTCXO AFC DAC value does not meet the tuning
requirements after tuning.
ISSUE 1 10/2005
Figure 31: 19.2 MHz VCTCXO reference clock
©2005 Nokia Corporation
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