User Manual

MM102225V1, Rev. B
52
6.5 BASE STATION TRANSMIT (BSX) FREQUENCY
ACCURACY TEST (MANDATORY)
Objective: The purpose of the Base Station Frequency Test is to verify that the DCX is
operating on the allocated frequency and compliant with the FCC specifications.
STEPS ACTION MISCELLANEOUS
1. Connect the PC to the DCX TERMINAL port.
2.
Using a suitable console application, enter the
sequence of commands indicated by the bold
script in the example on the right to return the
base station to digital mode.
offline
; <Various Shutdown Text is Displayed>
at@outmode1
OK
save_config
OK
reboot
; < The Base Station Reboots >
3. Repeat Steps 1 and 2 for all other DCX units.
4.
Select the RF GEN screen of the HP 8920 and
turn off the generator function by selecting the
Amplitude and pressing the ON/OFF /(YES)
key.
5.
Select the RF ANALYZER function of the HP
8920 and set the following parameters:
• Tune Mode: Auto
• Input Port: RF In
• Disconnect the I/Q cables to remove
modulation.
• Connect the HP 8920 RF/IN Port to
Bird Power Monitor TX Output Port.
6. Enable an HPA.
7. Record TX Frequency shown on Analyzer
11
.
TOL: Must be +
86Hz. CAUTION: Lock the
frequency counter/service monitor to a GPS
standard and then set the station frequency +
86Hz.
12
8. Disable the HPA.
9. Repeat on all other DCX units.
10. Replace I/Q Cables.
11
Refer to APPENDIX L - RECORDED DATA SHEET.
12
Ensure the GPS standard is better than 0.01ppm (about 1E-8 or better).