Powerwave Technologies 5JS0056 Multi Carrier RF Power Amplifier User Manual 273680

Powerwave Technologies Inc Multi Carrier RF Power Amplifier 273680

Manual 5

G3S-800-140-031 Installation & Service Manual  Copyright Powerwave Technologies, Inc., September 2001. All rights reserved 044-05095 Rev. A 5-1 September 2001 Section 5 Maintenance 5-1 Introduction This section contains periodic maintenance and performance test procedures for the Multicarrier Cellular Amplifier. It also contains a list of test equipment required to perform the identified tasks. NOTE Check your sales order and equipment warranty before attempting to service or repair the unit. Do not break the seals on equipment under warranty or the warranty will be null and void. Do not return equipment for warranty or repair service until proper shipping instructions are received from the factory. 5-2 Periodic Maintenance Periodic maintenance requirements are listed in table 5-1. Table 5-1 also lists the intervals at which the tasks should be performed. WARNING Wear proper eye protection to avoid eye injury when using compressed air. Table 5-1 Periodic Maintenance Task Interval Action Cleaning Air Vents 30 Days Inspect and clean per paragraph 5-4 Inspection Cables and Connec-tors 12 Months Inspect signal and power cables for frayed insulation. Check RF connectors to be sure that they are tight. Performance Tests 12 Months Perform annual test per paragraph 5-5. 5-3 Test Equipment Required For Test Test equipment required to test the amplifier system is listed in table 5-2. Equivalent test equip-ment may be substituted for any item, keeping in mind that a thermistor type power meter is re-quired. NOTE All RF test equipment must be calibrated to 0.05 dB resolution. Any deviation from the nominal attenuation must be accounted for and factored into all output readings.
G3S-800-140-031 Installation & Service Manual  Copyright Powerwave Technologies, Inc., September 2001. All rights reserved 044-05095 Rev. A 5-2 September 2001 Table 5-2 Test Equipment Required Nomenclature Manufacturer Model Signal Generator RDL IMD-801D-03A 30 dB Attenuator, 500 Watt Weinschel Corp. 53-30-34 20 dB Attenuator, 20 Watt (2 each) Tenuline Spectrum Analyzer H.P. 8560E Coax Directional Coupler H.P. 778D Power Meter/Sensor H.P. 437B/8481A Network Analyzer H.P. 8753C Current Probe 5-4 Cleaning Air Inlets/Outlets The air inlets and outlets should be cleaned every 30 days. If the equipment is operated in a se-vere dust environment, they should be cleaned more often as necessary. Turn off DC power source before removing fans. If dust and dirt are allowed to accumulate, the cooling efficiency may be diminished. Using either compressed air or a brush with soft bristles, loosen and remove accumulated dust and dirt from the air inlet panels. 5-5 Performance Test Performance testing should be conducted every 12 months to ensure that the amplifier system meets the operational specifications listed in table 5-3. Also verify system performance after any amplifier module is replaced in the field. The test equipment required to perform the testing is listed in table 5-2, and the test setup is shown in figure 5-1. NOTE The frequencies used in this test are typical for an amplifier with a 18 MHz band from 851 MHz to 869 MHz. Select evenly spaced F1, F2, F3, and F4 frequencies that cover the instantaneous bandwidth of your system. 5-5.1 Amplifier System Performance Test This test is applicable to the G3S-800-140-031 amplifier modules. To perform the test, proceed as follows: 1. Connect test equipment to the amplifier as shown in figure 5-1. NOTE Do not apply any RF signals at this time. Turn on signal generator and set frequency F1 to 854 MHz, F2 to 857 MHz, F3 to 863 MHz, and F4 to 866 MHz. Adjust each signal generator output so that the sum power output from all four signal generators equals -6 dBm at the input.
G3S-800-140-031 Installation & Service Manual  Copyright Powerwave Technologies, Inc., September 2001. All rights reserved 044-05095 Rev. A 5-3 September 2001 Unit Under TestG3S-800-140-031Plug-inAmplifier Module+27 VdcGnd RF InRFOut20 dBDirectionl Coupler30 dBAttenuator500 W20 dBAttenuator20 W Power MeterSensor Head8482A20dBAttenuator20WDirectionlCouplerPower MeterSensor Head8482ANetwork Analyzer8753CSignalGeneratorFilter /Isotlator10 dBVariableAttenuatorSpectrum Analyzer8651E Figure 5-1 Amplifier System Test Setup Diagram 5-5.1.1 Amplifier IMD Test And Current Test 2. Adjust attenuator for an input signal at -10 dBm. Turn on the amplifier by setting RF ON switch of amplifier. Adjust variable attenuator to set amplifier power output on power meter to 140 watts. Measure IMD on spectrum analyzer. IMD should be -60 dBc max. Record test data in table 5-3. Set RF ON switch to OFF. 3. With the amplifier module set at 140 watts power output, use the current probe (magnetic field type) and measure the dc current flow from the +27 Vdc power source. Current should be 70 amps maximum. Record test data in table 5-3. 5-5.1.2 Gain Test 4. Disconnect spectrum analyzer from test setup, and connect the network analyzer. 5. Set network analyzer as follows: ¾ Power output to -10 dBm. ¾ Frequency start to 869 MHz. ¾ Frequency stop to 894 MHz. ¾ Normalize the network analyzer for gain and return loss. 6. Check the gain across the band from 869 MHz to 894 MHz. Gain should be between 58 dB. Record test data in table 5-3. 5-5.1.3 Harmonics Test 7. With the power set at 140 watts power output, use the spectrum analyzer and check the fre-quency band from 851 MHz to 869 MHz for harmonics. Harmonics should be 5 dBm maxi-mum. Record test data in table 5-3.
G3S-800-140-031 Installation & Service Manual  Copyright Powerwave Technologies, Inc., September 2001. All rights reserved 044-05095 Rev. A 5-4 September 2001 5-5.1.4 Spurious Test 8. With the power amplifier set at 140 watts power output, use the spectrum analyzer and check the frequency band from 851 MHz to 869 MHz for spurious signals. Spurious signals should be -60 dBc maximum. Record test data in table 5-3. 5-5.1.5 Input Return Loss Test 9. Reset and turn on amplifier module. Read and record the S11 return loss measurement on network analyzer. Input return loss should be –16 dB maximum. Record test data in table 5-3.
G3S-800-140-031 Installation & Service Manual  Copyright Powerwave Technologies, Inc., September 2001. All rights reserved 044-05095 Rev. A 5-5 September 2001 Table 5-3 Multicarrier Cellular Amplifier Test Data Sheet DATE _________________________________ AMPLIFIER S/N _________________________ TEST CONDITIONS: Load and Source Impedance: 50 Ohms VSWR: < 1.2:1 Supply Voltage: +27 Vdc ±1.0 Vdc TEST SPECIFICATION MIN MAX DATA 4-TONE IMD Vcc = 27 Vdc PO = 140 W Freq.: 853, 857, 863, and 866 MHz -60 dBc RF Gain Vcc = 27 Vdc PO = 140 W Freq. = 860 MHz 57.5 dB 58.5 dB Gain Flatness Vcc = 27 Vdc ±1 Vdc PO =140 W 851-869 MHz Band -0.5 dB +0.5 dB Harmonics Vcc = 27 Vdc PO = 140 W 851-869 MHz Band 5 dBm Spurious Vcc = 27 Vdc PO =140 W 851-869 MHz Band -60 dBc Input Return Loss Vcc = 27 Vdc PO = 140 W 851-869 MHz Band -16 dB DC Power Vcc = 27 Vdc PO = 140 W 4 Tones 70 Amps PASS _________________________________ FAIL ______________________________ Tested by ______________________________
G3S-800-140-031 Installation & Service Manual  Copyright Powerwave Technologies, Inc., September 2001. All rights reserved 044-05095 Rev. A 5-6 September 2001 5-6 Field Replaceable Parts And Modules The following parts and modules can be replaced in the field on site by a qualified technician with experience maintaining RF power amplifiers and similar equipment: 1. G3S-800-140-031 power amplifier modules 2. Cooling fans 5-6.1 G3S-800-140-031 Power Amplifier Module To replace a power amplifier module, proceed as follows: 1. Set both the RF ON On/Off/Reset switch and the power ON/OFF switch on the front panel of the amplifier module to OFF. 2. Loosen two screws that secure amplifier module to subrack. 3. Use handle on front of module, and with a steady even pressure, pull module out of subrack. CAUTION When removing the amplifier from the subrack, it is very important to support the amplifier such that the rear of the module does not suddenly drop when it disengages from the track. A drop such as this could damage the module. 5-6.2 Cooling Fans To replace a cooling fan, proceed as follows: 1. Remove amplifier module from subrack; see paragraph 5-6.1 preceding. 2. Loosen four snap fasteners that secure fan to amplifier module. Disconnect fan power con-nector from amplifier module. Install replacement in reverse order of steps 1 and 2 above.

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