User's Manual Part 3

BTS Redundancy/Alarm Testing – continued

Mar 2001

3-95

68P09253A61

SCt4812T CDMA BTS Optimization/ATP

DRAFT

LPA Redundancy Test

Follow the procedure in Table 3-51 to verify redundancy of the LPAs.

First verify there are no BBX channels keyed BEFORE

moving the antenna connection. Failure to do so can result

in serious personal injury and/or equipment damage.

WARNING

Table 3-51: LPA Redundancy Test

Step Action

1 From the pulldown menu select:

Device > Set Redundant Sector > None/0

Device > Set Pilot > Only > Carrier–#–1-1

Device > Set Pilot > Only > Carrier–#-1-1 and Pilot Gain = 262

2 Key-up the BBX assigned to the LPAs associated with the sector under test (gain = 40).

3 Adjust the communications test set spectrum analyzer, as required, to observe the overall carrier

amplitude and IM Shelf and note for reference. These figures will be required later.

NOTE

See Figure 3-13 for test equipment setup, if required.

4 Push-in and release the breaker supplying the 1st LPA of the pair.

NOTE

After power is removed, IM suppression takes a few seconds to settle out while compensating for the

removal of the 1st LPA. The overall gain decreases by approximately 6 dB. The process must be

complete before proceeding.

5 Verify:

• The other LPA module did not go OOS due to the loss of the LPA.

• The overall carrier amplitude is reduced by approximately 6 dB and IM suppression on the analyzer

display remains basically unchanged.

• LPA fault message is reported via the MGLI and displayed on the alarm monitor.

6 Re-apply power to the LPA module and observe the alarm has cleared on the alarm monitor.

NOTE

All PWR/ALM LEDs should be GREEN at completion of test.

7 Repeat Steps 4 through 6 to verify the 2nd LPA of the pair.

8 De-key the BBX.

n WARNING

First verify there are no BBX channels keyed when moving the antenna connection. Failure to do so

can result in serious personal injury and/or equipment damage.

9 Repeat Steps 1 through 8 to verify LPAs assigned to sectors 2 and 3 (if equipped). Move the test cable

on top of the BTS to TX OUT 2 and TX OUT 3 antenna connectors as required.