Nokia NPL-3 Series Troubleshooting Instructions page 22

NPL-3
Troubleshooting Instructions
- Set Rx/Tx channel to 190 on GSM850 band, 700 on GSM1800 band or 661 on
GSM1900 (Defaults)
Apply 881.6671 MHz (channel 190 + 67.710 kHz offset), 1842.86771 MHz (channel 700
+ 67.710 kHz offset) or 1960.06771 MHz (channel 661 + 67.71 kHz) –90 dBm signal to
the RF-connector (remember to compensate for cable attenuation).
Measuring with an oscilloscope on "RXI" or "RXQ" following screens should be seen on a
working GSM850 , GSM1800 or GSM1900 receiver:
Figure 18, "RX I/Q signal ,burst mode, input level –90dBm.," on page 22: Receiver I or Q
burst mode signal (channel 190) measured from testpoint RXI or RXQ with 881.6671
MHz signal, input level –90dBm at RF-connector.
Correct signal amplitudes approximately:
• GSM850~170mVpp
• GSM1800~140mVpp
• GSM1900~160mVpp
Signal part frequency 67.7kHz sine.
Page 22
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RX I/Q signal ,burst mode, input level –90dBm.
Figure 18:
ãNokia Corporation.
CCS Technical Documentation
Issue 1 3/03