User's Manual

Commissioning High Power Wideband Radio Head (WRH-V)

3-10 044-05251 Rev B

Where f

and f

are two TX signals entering a WRH-V. The specification for the maximum allowed PIM is -115

dBm per 100 kHz resolution bandwidth at rated output power. To test for PIM follow the steps listed in

Table 3-4.

Table 3-4 PIM Testing Procedure

Step Action

1 If BTS signals are present, continue with step 2. Otherwise, connect two signal generators to OCM

and set frequencies such that products are in relevent receive band (see equations above)

2 Set WRH-V UL gain to 60 dB and DL gain such that desired per carrier power is presented at output

port

3 Set Spectrum Analyzer to 100 kHz resolution bandwidth and view RX band at 3

order product

frequency calculated in step 1

4 Loosen fastening screw in each corner on front cover of WRH-V under test, and open cover

5 Verify the noise floor specification for the Spectrum Analyzer. If the noise floor is higher than or equal

to -85 dBm/100 kHz, locate FON, disconnect UL cable from port P101 and connect

SpectrumAnalyzer to the cable using an SMA female - female connector (noise limit becomes -115

dBm + 60 dB = -55 dBm). Continue with step 7.

6 If noise floor is lower than -85 dBm/100 kHz, locate the FON card and connect the Spectrum Analyzer

to P117 (noise limit becomes -115 dBm + 60 dB - 30 dB = -85 dBm). If the FON only has three RF

ports on the left side, port P117 will not be available, so follow instructions listed in step 5.

7 Enable WRH-V TX signal. For details on using OM-Online, see OM-Online user manual

8 Using Spectrum Analyzer, measure noise level. If no noise exists above calculated limit in step 5

(-55 dBm) or step 6 (-85 dBm) above, as appropriate, then test is passed and no other action is

necessary

9 If a higher level of noise exists, disable the WRH-V TX signal and disconnect cable to DAS at bottom-

left outside corner

10 Connect low PIM load onto WRH-V Service antenna connector at bottom-left outside corner. Tighten

connectors securely

11 Remeasure noise level. If no noise exists above calculated limit in step 5 (-55 dBm) or step 6 (-85

dBm) as appropriate, then DAS has a PIM issue. Tighen all connections in DAS with torque

wrenches, replace any cripmed or severely bent cables, and retest. Repeat until all issues are solved

12 Otherwise, if noise is higher than limit, WRH-V is defective and must be replaced. See Chapter 4 for

Replacement procedures