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10-2

September 27, 2000

68P81093C75-O

Power Amplifier 
Module Operation

The PDR 3500 uses the mid-power Spectra RF power amplifier (RF 
PA) board, housed in a heavy-duty, shielded, aluminum heat sink.  
The gain of the RF PA board is controlled by the power control 
voltage from the Exciter Module.

The modulated RF signal is amplified by the RF PA and sent to the 
site transmit antenna.  

The transmit path inside the RF PA contains a directional coupler 
(calibrated at setup), which feeds a DC voltage (proportional to the 
output power) to the TX Power Control Circuitry in the Exciter 
Module. This signal serves as the feedback signal in the power 
control loop.

Receiver Circuitry 

Introduction

The Receiver Circuitry performs the following functions:

• Accepts receive RF signals from the site receive antenna 

• Filters and dual conversion 

• Outputs a digitized receive signal to the Station Control Module.

Receiver Module 
Operation

The receive signal is generated from the site receive antenna to a 
multi-pole, preselector filter which provides highly selective 
bandpass filtering.  

The filtered signal is then amplified and fed to the RF input of the 1st 
mixer. 

The 1st mixer combines the filtered signal with an injection signal 
generated by the Synthesizer/VCO. This results in a 21.45 MHz 
(VHF), or 73.35 MHz (UHF) 1st IF (intermediate frequency) signal. 
(The injection signal is determined by frequency programming data 
from the Station Control Module via the SPI bus.)

The 21.45 or 73.35 MHz 1st IF is filtered and routed to a custom 
receiver IC. This component contains the following circuitry:

• 2nd injection and mixing 

• Amplification 

• A/D (analog to digital) conversion 

This results in a digitized receive signal. This signal is routed to the 
Station Control Module as differential data.

Summary of Contents for PDR 3500

Page 1: ...1 PDR 3500 Portable Repeater Basic Service Manual ...

Page 2: ...nna Installation 2 4 3 Introduction 3 1 General 3 1 Compact Mechanical Design 3 1 State of the Art Electrical Design 3 1 Transmitter Circuitry 3 1 Receiver Circuitry 3 1 Station Control Module 3 1 Wireline Circuitry 3 2 Switching Power Supply 3 2 Standard Features 3 2 Optional Hardware Features 3 2 4 System Applications 4 1 Local Control 4 1 Two Antenna Operation 4 1 External Duplexer Operation 4 ...

Page 3: ...preting LED Indicators 9 6 Interpreting Alarm Alert Tones 9 10 Introduction 9 10 Verifying Transmitter Circuitry 9 11 Required Test Equipment 9 11 Verifying Transmitter Circuitry Procedure 9 11 Verifying Receiver Circuitry 9 15 Required Test Equipment 9 15 Verifying Receiver Circuitry Procedure 9 16 Verifying Receiver Circuitry Digital Capable Stations 9 21 Required Test Equipment 9 22 Wiring Diag...

Page 4: ...ield Tuning Procedure 9 35 Required Test Equipment 9 36 VHF Tuning Procedure 9 36 Calculating Proper Alignment Frequency 9 36 Preparing Equipment 9 37 VHF Tuning Procedure 9 38 UHF Tuning Procedure 9 39 Calculating Proper Alignment Frequency 9 39 Preparing Equipment 9 40 Tuning Procedure 9 41 10 Functional Theory of Operation 10 1 Transmitter Circuitry Operation 10 1 Introduction 10 1 Exciter Modu...

Page 5: ...d or Suspected Problem 9 4 Figure 5 PDR 3500 LED Indicators and Front Panel Buttons and Connectors 9 9 Figure 6 Test Equipment Setup for Verifying Transmitter Circuitry 9 12 Figure 7 Test Equipment Setup for Verifying Receiver Circuitry 9 17 Figure 8A Coupled receiver connection Top B Coupled duplexer connection Bottom 9 19 Figure 9 Disabling the Transmitter 9 20 Figure 10 Interconnect Diagram 9 2...

Page 6: ...lusive rights for copyrighted computer programs including the exclusive right to copy or reproduce in any form the copyrighted computer program Accordingly any copyrighted Motorola computer programs contained in the Motorola products described in this manual may not be copied or reproduced in any manner without the express written permission of Motorola Furthermore the purchase of Motorola product...

Page 7: ...LEX 280127 FAX 1 847 538 8198 FAX 1 410 712 4991 Federal Government Domestic U S A after hours or weekends 1 800 925 4357 International 1 847 538 8023 Motorola Parts Accessories and Aftermarket Division United States and Canada Attention Order Processing 1313 E Algonquin Road Schaumburg IL 60196 Accessories and Aftermarket Division Attention International Order Processing 1313 E Algonquin Road Sch...

Page 8: ...quency RF energy Exposure to Radio Frequency Energy Your Motorola radio is designed to comply with the following national and international standards and guidelines regarding exposure of human beings to radio frequency electromagnetic energy EME United States Federal Communications Commission Code of Federal Regulations 47 CFR part 2 sub part J American National Standards Institute ANSI Institute ...

Page 9: ...akers The Health Industry Manufacturers Association recommends that a minimum separation of 6 inches 15 cm be maintained between a handheld wireless radio and a pacemaker These recommendations are consistent with the independent research by and recommendations of Wireless Technology Research Persons with pacemakers should ALWAYS keep the radio more than 6 inches 15 cm from their pacemaker when the...

Page 10: ...ies in such areas Sparks in a potentially explosive atmosphere can cause an explo sion or fire resulting in bodily injury or even death NOTE The areas with potentially explosive atmospheres referred to above include fueling areas such as below decks on boats fuel or chemical transfer or storage facilities areas where the air contains chemicals or particles such as grain dust or metal powders and a...

Page 11: ...ssure optimal performance and make sure human exposure to radio frequency electromagnetic energy is within the guidelines set forth in the above standards The antenna must be mounted outside the building Mount the antenna on a tower if at all possible If the antenna is to be mounted on a building then it must be mounted on the roof As with all fixed site antenna installations it is the responsibil...

Page 12: ...ously monitored by an internal calibrated wattmeter The wattmeter output feeds a power control loop continually adjusting and maintaining the desired output power All adjustments are electronic including deviation and output power Receiver Circuitry The station receive circuitry features multiple bandwidth capability 12 5 25 or 30 kHz depending on band as well as ASTRO digital operation Injection ...

Page 13: ...ce philosophy Easily programmed via Radio Service Software Local or Remote Software downloading to FLASH memory Upgrades performed by module replacement and or software upgrade Compatible with appropriate options with analog SECURENET ASTRO and ASTRO CAI digital signaling Versatile and reliable switching type power supply Wide operating temperature range 30 C to 60 C 22 F to 140 F Optional Hardwar...

Page 14: ...ay be operated with the internal duplexer using a single antenna The duplexer provides the necessary electrical isolation between the transmitter and the receiver frequencies for repeater operation The same isolation can be obtained by physically separating transmit and receive antennas either horizontally or vertically The repeater requires approximately 50 dB isolation between the transmit and r...

Page 15: ...G58 style cables have to be used keep the cables as far apart as possible to minimize cable coupling External Duplexer Operation The PDR 3500 must be used with an external duplexer when frequency spacing is less than 3 MHz The duplexer isolation required for proper operation is approximately 60 dB Double shielded coaxial cables must be used from the repeater to the duplexer Repeater RA or Cross Ba...

Page 16: ... R1 X PLE1256 Receiver UHF R2 X PLE1257 Exciter UHF R2 X PLE1258 Receiver UHF R3 X PLE1259 Exciter UHF R3 X PLE1260 Receiver UHF R4 X PLE1261 Exciter UHF R4 X X X X X X PLN1682_ Board Control X X X X X X PLN1681_ Chassis main X X X X X X PLN7776_ Case portable X X X X X X PLN7777_ Board backplane X X X X X X PPN6026_ Power supply X X PLD7981_ PA VHF X PLE9367_ PA UHF R1 X X PLE9369_ PA UHF R3 X PL...

Page 17: ...68A P2069A P2070A P2071A Channel spacing 12 5 25 30 kHz 12 5 25 kHz Stability 0 0001 0 0001 Preselector bandwidth 3dB 7 MHz 7 MHz Squelch Carrier PL DPL Carrier PL DPL Number of modes 1 1 TRANSMITTER VHF UHF RF power without duplexer 30 watts 30 watts RF power with duplexer 20 watts 20 watts Maximum transmit duty cycle 50 50 TX spurs harmonics 60 dB 60 dB FM noise EIA 45 dB nominal 45 dB nominal A...

Page 18: ... duplexer T R separation 3 MHz 403 520 MHz AC power voltage range 80 265 Vac AC power frequency input 49 61 Hz External DC power 11 16 Vdc CURRENT DRAIN High power repeat 10 0 A Standby 1 9 A DIMENSIONS Size English 20 00 x 15 x 7 75 inches Size metric 508 X 381 X 197 mm WEIGHT Weight English 41 lbs Weight metric 18 6 kg Note Specifications are subject to change without notice ...

Page 19: ...5 4 September 27 2000 68P81093C75 O Notes ...

Page 20: ...be used The magnetic mount whip antenna Motorola part number PAN6003A shipped with the PDR 3500 NOTE This antenna should be cut to frequency before use per the manufacturer s instructions enclosed with the antenna An aftermarket antenna which meets these requirements Monopole Unity gain Tuned to the frequency at which the antenna is to be used Minimum input power rating of 60W continuous VSWR of 1...

Page 21: ...Running H F 6 September 27 2000 68P81093C75 O Notes ...

Page 22: ...to the PC refer to Quantar RSS User s Guide 68P81085E35 the PC must be electrically connected to the PDR 3500 via the RSS port located on the top panel For this connection a 9 pin female to 9 pin male EIA 232 cable is available Motorola part number 30 80369E31 from the Accessories and Aftermarket Product Division AAD formerly known as Motorola National Parts A cable can also be made using the wiri...

Page 23: ...TE Rx Freq Band 2 should be set to NONE 4 The PA Power Rating field should be set to 25W low power and the Power Supply field should show AC LOW The PDR 3500 was designed using a Quantar low power station profile It will not operate properly using any other configuration 5 If the unit is equipped with a Wireline Card verify that the Wireline field under the options is set to 4 wire Once the Hardwa...

Page 24: ... on make sure the value shown in the RSS screen is 90 dBm If it is not type in 90 dBm 5 Press F8 to save the calibration 3 Power Out 1 In the Alignment Menu Screen tab over to the Tx Power field and press F2 to perform the alignment 2 For this procedure connect the Tx UHF type connector on the station top panel to the RF input of either a Motorola R 2670 Communications Analyzer or to the input of ...

Page 25: ...R 3500 receive frequency and the output level to 113 dBm with modulation either V 52 or Project 25 1011 Pattern generation 4 Press F2 to perform the alignment The values for the report will appear on the RSS screen Channel Information From the Main Menu press F4 Press F4 again to arrive at the Channel Information Screen From this screen the user may configure the TX RX frequencies RF power out mod...

Page 26: ...tion top panel Plug the 3 prong plug into a 110 V or 220 V AC grounded outlet NOTE The Power Supply module automatically selects between 110 V and 220 V DC Input Power Connection An optional six foot fused 2 conductor DC power cord is available Attach the alligator clip leads Red Black to an external battery or some other DC source set to 12 V Plug the molded connector end to the external DC conne...

Page 27: ... to the UHF connector labeled RX on the top panel and the Tx antenna to the UHF connector labeled TX Figure 2 Please refer to the Antenna Spacing Chart on page 4 1 in this manual Duplexer The duplexer allows the PDR 3500 to use a single antenna for both transmit and receive 1 Connect the UHF connector labeled RX on the station top panel to the N type connector labeled RX on the duplexer 2 Connect ...

Page 28: ...mary of LED Indicators NOTE Refer to the Troubleshooting section of this manual for the detailed descriptions and interpretation of the LED indicators The following LED indicators are provided to show the operating status of the station See Figure 2 for the location of these indicators Table 6 Switches Pushbuttons and Connectors Top Panel Wireline connectors Transmit UHF connector RSS port connect...

Page 29: ...nd Fuses AC Inlet 110 220 Vac 3 A D Power Transmit LED The function of this LED indicator is described in the Trou bleshooting section of this manual E Momentary PTT Reset Switch When set to PTT its purpose is to test the station When set to RESET its purpose is to reset the station F Control Module Status LEDs The function of these LED indicators is described in the Troubleshooting section of thi...

Page 30: ...t repair procedures Performing alignment after replacing defective modules Recommended Test Equipment Follow this list of recommended test equipment when performing troubleshooting procedures on the PDR 3500 station and ancillary equipment Test Equipment List Motorola R2001 or R2600 Series Communications Analyzer or equivalent PC with RSS program In Line Wattmeter Motorola S 1350 or equivalent Dum...

Page 31: ...es of non intrusive tests performed during a routine maintenance The technician verifies proper station operation An overview of the procedure is shown in the flowchart Figure 3 Procedure 2 Troubleshooting A Reported Suspected Problem Procedure 2 should be used when an equipment problem has been either reported or is suspected The procedure includes tests that allow the technician to troubleshoot ...

Page 32: ...F BEING FAULTY MODULE SUSPECTED GO TO TROUBLESHOOTING PROCEDURE 2 FLOW CHART YES INTERPRET STATUS REPORT RSS USER S GUIDE 68P81085E35 USING RSS ACCESS THE STATUS REPORT SCREEN AND LOOK AT HISTORY OF ALARMS AND TIME STAMPS NO GO TO TROUBLESHOOTING PROCEDURE 2 FLOW CHART YES NO RUN STATION DIAGNOSTICS RSS USER S GUIDE 68P81085E35 USING RSS RUN DIAGNOSTICS ON STATION MODULES GO TO TROUBLESHOOTING PRO...

Page 33: ...DICATES STATION YES NO YES NO RUN STATION DIAGNOSTICS RSS USER S GUIDE 68P81085E35 USING RSS ACCESS DIAGNOSTICS SCREEN RUN DIAGNOSTICS AND INTERPRET RESULTS YES NO PROCEDURE 2 USING RSS ACCESS THE STATUS REPORT SCREEN ANALYZE MESSAGES TO DETERMINE IF MODULE FAILURE HAS OCCURRED USING RSS DOWNLOAD STATION SOFTWARE TO FLASH MEMORY ON STATION CONTROL BOARD NO YES OF BEING FAULTY MODULE SUSPECTED OF B...

Page 34: ...COMPARE TO CODE PLUG FILE ON PC FOR PARTICULAR STATION CODE PLUG PROGRAMMING CORRECT RE PROGRAM STATION CODE PLUG BY DOWNLOADING CUSTOMER DATA FROM CODE PLUG FILE FOR PARTICULAR STATION RSS GUIDE 68P81085E35 IF PROBLEM STILL EXISTS PROCEED TO INTERPRET STATUS REPORT INTERPRET STATUS REPORT RSS USER S GUIDE 68P81085E35 USING RSS ACCESS THE STATUS REPORT SCREEN AND LOOK AT HISTORY OF ALARMS AND TIME...

Page 35: ... power is not at expected power level as set by technician via RSS during station alignment PA Low YELLOW when transmitter is keyed and PA output power is less than expected power level as set by technician via RSS during station alignment but not shut down for example during power cutback mode OFF when PA not keyed or PA keyed and PA output power is at expected power level as set by technician vi...

Page 36: ...nctional unused in PDR 3500 OFF when RECEIVER is functional or no receiver module installed A receive module is considered non functional if a failure is detected during diagnostics run at time of power up or during normal operation Aux LED GREEN LED available for special application function All LEDs Flashing On and Off in Unison Station is in Software download mode either initiated by the RSS or...

Page 37: ...9 8 September 27 2000 68P81093C75 O ...

Page 38: ...tation On Station Fail Intrem AccD Control Ch Rx 1 Active Rx 2 Active Rx Fail Aux LED Speaker RSS Port Intercom Shift CSQ PL Off Vol Up Local PTT Vol Down Access Disable EXCITER MODULE Front Panel WIRELINE INTERFACE MODULE Front Panel STATION CONTROL MODULE Front Panel Cover Plate Removed PWR Tx PTT Reset Switch TOP PANEL OF STATION MAEPF 27030 O Handset ...

Page 39: ... second window with two seconds between successive alarms when more than one alarm is active The following two examples illustrate the timing of the alarm tones The alarm tone definitions are as follows Example 1 Single Alarm 3 beep beep beep repeats Alarm 3 10 Second Window Example 2 Multiple Alarms 1 and 4 beep beep beep beep beep repeats 2 seconds Alarm 1 Alarm 4 10 Second Window Number of Beep...

Page 40: ...In general the transmitter circuitry is exercised by injecting and measuring signals using a Motorola R2001 Communications Analyzer or equivalent Measured values outside the acceptable range indicate a faulty module values within range verify proper operation of the above listed modules and circuitry Required Test Equipment The following test equipment is required to perform the procedure Motorola...

Page 41: ... transmit output port Duplexer or Antenna Relay Antenna Port To Antenna In line Wattmeter Antenna RF Port Select Knob Pull Out Motorola R2001 Communications Analyzer Dummy Load If duplexer or antenna relay is used connect N to N cable from antenna port to in line wattmeter otherwise connect UHF to N cable from top panel transmit jack to in line wattmeter Connect wattmeter to dummy load Connect ant...

Page 42: ... 4 Measure output power by pressing the PTT button and observing the reading on the in line wattmeter If the PA output is not at the proper power as set for the particular station adjust the output power as described in the Setup and Connections section of this manual If the station will not output the rated power and the output is being measured through a duplexer or antenna relay the duplexer co...

Page 43: ...y Exciter or Station Control Module If the display shows a single carrier moving erratically suspect the following Faulty Station Control Module Faulty Exciter Module Faulty PA Module Step 6 If the display is okay setup R2001 to display modulation Using the handset push the PTT button and speak into the mouthpiece Verify that the display shows If the proper display is not obtained suspect faulty S...

Page 44: ...uding Receiver Module Power Supply Module 2 1 MHz Reference Oscillator Circuitry Receiver related circuitry in the Station Control Module SCM In general the receiver circuitry is exercised by injecting and measuring signals using a Motorola R2001 Communications Analyzer or equivalent Measured values outside the acceptable range indicate a faulty module values within range verify proper operation o...

Page 45: ...cation of the PL CSQ Off button If no audio is heard suspect the following Faulty Receiver Module Faulty Station Control Module R2001 is outputting a carrier signal Step 3 Set R2001 to generate a 0 5 µV 13 dBm FM signal at the PDR 3500 receiver frequency modulated by a 1 kHz tone at 3 kHz deviation The 1 kHz tone should be audible through the handset or external speaker If no audio is heard suspec...

Page 46: ...Analyzer Dummy Load PDR 3500 Top Panel Connect UHF to N cable from station top panel receive port to R2001 RF in out Connect UHF to N cable from top panel transmit port to dummy load Connect handset to RJ 11 jack on front panel of Station Control Module or External Speaker to RJ 11 jack 3 2 1 MAEPF 27033 O Handset PTT Button RF SECTION MONITOR OSCILLOSCOPE COMMUNICATIONS SYSTEM ANALYZER 1 0 2 3 4 ...

Page 47: ...R2001 to station RF cable NOTE To measure 12 dB SINAD the station must be programmed for mixed mode Analog Digital operation Incorrect reading will result if programmed for Digital Only operation NOTE For VHF and UHF stations only refer to 5 Preselector Field Tuning Procedure in this section Procedures for tuning the receiver preselector are described Step 8 If the station is configured with a dup...

Page 48: ...e should not light even when the station is receiving Figure 8 A Coupled receiver connection Top B Coupled duplexer connection Bottom RX TX RF SECTION MONITOR OSCILLOSCOPE COMMUNICATIONS SYSTEM ANALYZER 1 0 2 3 4 5 6 7 8 9 Duplexer PDR 3500 Top Panel Capacitive Coupler Isolated T RF Output Motorola R2001 Communications Analyzer Dummy Load MAEPF 27035 O RX TX RF SECTION MONITOR OSCILLOSCOPE COMMUNI...

Page 49: ...sure the 12 dB SINAD once again and note the result The difference between this 12 dB SINAD level and the level measured in Step 11 reflects the insertion loss of the duplexer The difference should be no greater than approximately VHF 1 3 dB UHF 1 6 dB If the difference is greater suspect the following Duplexer receive and transmit ports are reversed Loose or damaged cables between the duplexer an...

Page 50: ...mended Step 16 If the station is not digital capable the Verifying Receiver Circuitry test procedure is complete The receiver circuitry is considered to be operating properly if all displays and measurements are correct 1 Remove the test equipment 2 Restore the station to normal service 3 Return to the troubleshooting flow chart to resume the troubleshooting sequence If the station is digital capa...

Page 51: ...ons only IMPORTANT If the station operates as a repeater the transmit output from the station must be connected to a dummy load to prevent over the air broadcast during receiver testing Step 1 Proceed to ASTRO Bit Error Rate Report located in Chapter 4 of the RSS User s Guide part number 68P81085E35 Follow the instructions for setting up the test equipment and initiating a BER report using the RSS...

Page 52: ...is greater than 5 tune the preselector and re check the BER reading If a reading of 5 or less cannot be achieved replace the Receiver Module Step 5 This completes the Verifying Receiver Circuitry test procedure If all displays and measurements are correct the receiver circuitry may be considered to be operating properly 1 Remove test equipment 2 Restore the station to normal service 3 Return to th...

Page 53: ... station E Top panel DB 9 connector Backplane connector J20 RSS interface ribbon cable assembly F Top panel LED Switch Backplane Molex P5 P9 LED Switch assembly G Chassis cooling fans Backplane 3 pin Molex P5 Cooling fan assembly H Backplane terminals RED BLK PA 14 VDC input 14 VDC to PA I Backplane connector P10 PA Control feedback ribbon cable J PA mini UHF Top panel UHF Transmit RF coaxial cabl...

Page 54: ... prevention of static protection is provided in Motorola publication number 68P81106E84 available through the Accessories and Aftermarket Division Some additional precautions are as follows A wrist strap Motorola part number RSX4015A or equivalent should be worn while servicing the equipment to minimize static buildup Figure 11 Chassis Ground Wiring Diagram Output Input Gnd Neg Pos H N Power Suppl...

Page 55: ... the backplane connector contacts If the cleaning of gold plated contacts is required use a soft cloth dampened with alcohol to lightly wipe the contacts Be sure not to touch the contact surfaces with your fingers finger oils and salts can contaminate the contact surfaces Power Down Station Before Removing Inserting Modules Before removing or inserting a module into the station chassis and engagin...

Page 56: ...s top panel and lift the chassis out of the case 3 Remove the cover plate on the left end of the front of the station by removing two Torx screws from the front of the plate Remove the four Phillips screws from the side and bottom edges of the plate 4 Pull out the old Control Module by gripping behind its DB 9 RJ 11 and RJ 45 connectors distributing pressure equally among the connectors 5 Insert t...

Page 57: ...ns only Simulcast ASTRO Launch Time Offset For 6809 Trunking stations only TDATA Wireline Physical Replacement of the Wireline Module 1 Turn off the station s power by unplugging the AC and DC power cords from the top panel 2 Remove the eight Phillips screws from the edges of the station s top panel and lift the chassis out of the case 3 Remove the cover plate on the left end of the front of the s...

Page 58: ...y reversing Steps 2 and 3 After Installing the New Wireline Module Perform the following alignment procedures as described in the RSS User s Guide part number 68P81085E35 Rx Wireline Tx Wireline ASTRO Modem Card V 24 Interface Card Physical Replacement of the Card 1 Remove the Wireline Module as described above 2 Unplug the faulty ASTRO Modem Card or the V 24 Interface Card from the Wireline board...

Page 59: ...at the connectors 7 If desired power up the station while it is still out of the case to make sure the module is securely in place If any of the LEDs do not light are dim or flash rapidly one or more of the modules are not seated properly 8 For VHF and UHF stations tune the preselector using the procedure in the Maintenance subsection Preselector Field Tuning Procedure Before continuing to the nex...

Page 60: ...chassis remove the six Phillips screws holding the Exciter s mounting plate Slide the mounting plate out of the front of the chassis 5 Pull out the old Exciter Module by gripping behind the mini UHF connector and pulling gently 6 Insert the new module Make sure it is flat on the bottom of the chassis Push it firmly into the chassis until it seats into the card edge connectors on the backplane Do n...

Page 61: ...new PA matches the one being replaced and The Exciter is not being changed If the PA band or the Exciter band is being changed the DIP switches must be configured to match the new frequency of the PA and Exciter Detach the motherboard from the chassis and set the switches as described in the Backplane subsection of Module Replacement Physical Replacement of the Power Amplifier 1 Turn off the stati...

Page 62: ...and secure it with the eight Phillips screws around the top panel After Installing the New Power Amplifier Perform the following alignment procedures as described in the RSS User s Guide part number 68P81085E35 or the Setup and Connections section of this manual or both Power Output Power Supply Physical Replacement of the Power Supply 1 Turn off the station s power by unplugging the AC and DC pow...

Page 63: ... 3 Remove the cover plate on the left end of the front of the station by removing two Torx screws from the front of the plate and four Phillips screws from the side and bottom edges of the plate 4 Pull the Station Control Module and Wireline Module until they disengage from their respective backplane connectors The modules need not be completely removed from the chassis 5 On the back of the chassi...

Page 64: ...assis 14 Finish reassembling the station by reversing Steps 2 and 3 After Installing the New Power Amplifier Perform the following alignment procedures as described in the RSS User s Guide 68P81085E35 or the Setup and Connections section of this manual or both Power Output Using the RSS run a complete battery of diagnostics to exercise all boards and modules Preselector Field Tuning Procedure The ...

Page 65: ...yzer can both generate and measure simultaneously The R2001 may be used for either the generator or monitor function but not both simultaneously When using the R2001 as a signal generator RF signal must be taken from the antenna port VHF Tuning Procedure Calculating Proper Alignment Frequency Use one of the following two methods to calculate the alignment frequency to be generated by the signal ge...

Page 66: ...tep 2 For stations with multiple receive frequencies calculate the frequencies of the alignment signal as follows Step 1 From the site documentation or the RSS note the receive frequency for each channel supported by the station Step 2 Calculate a midpoint frequency as follows Fmid Fhighest Flowest 2 Step 3 Using Fmid in place of the station receive frequency perform Step 2 through Step 4 above Pr...

Page 67: ...5 Using the torque driver and deep well socket tighten the five tension nuts on the adjustment screws to 6 in lb Step 6 Connect the test equipment as shown in Figure 12 VHF Tuning Procedure Step 1 Provide power to the PDR 3500 through either DC or AC to provide the active 50 Ω termination Step 2 Adjust the signal generator to the frequency calculated on page 36 Set the level to 5 dBm Figure 12 Tes...

Page 68: ...OTE The DIP will not be as sharp for screw 5 as it was for screws 2 through 4 UHF Tuning Procedure Calculating Proper Alignment Frequency Use one of the following two methods to calculate the alignment frequency to be generated by the signal generator For stations with a single receive frequency calculate the frequency of the alignment signal as follows Step 1 From the site documentation or the RS...

Page 69: ... 4 determine the alignment frequency as follows If the frequency from Step 1 is 518 MHz then the alignment frequency 518 MHz If the frequency from Step 1 is 472 MHz then the alignment frequency 472 MHz Otherwise use the actual frequency from Step 1 For stations with multiple receive frequencies calculate the frequencies of the alignment signal as follows Step 1 From the site documentation or the R...

Page 70: ...and 4 clockwise until they bottom out Be careful not to apply more than 3 in lb of torque to prevent warping the preselector cover and housing Step 6 Connect the test equipment as shown in Figure 14 Tuning Procedure Step 1 Turn the station power supply ON to provide the active 50 Ω termination Step 2 Adjust the signal generator to the frequency calculated on page 39 Set the level to 5 dBm Figure 1...

Page 71: ...n nut on tuning screw 3 to at least 12 in lb and fine tune tuning screw 3 for a DIP Step 7 Insert the tuning probe into cavity U3 and decrease the output from the signal generator to 5 dBm Step 8 Adjust tuning screw 4 for a DIP Step 9 Tighten tension nut on tuning screw 4 to at least 12 in lb and fine tune tuning screw 4 for a DIP Figure 15 Location of Tuning Screws and Cavity Probe Holes To Recei...

Page 72: ...ignal at the desired transmit frequency It sends this signal to the Power Amplifier for amplification The circuitry operates as follows 1 The Synthesizer Voltage Control Oscillator VCO accepts frequency programming data from the Station Control Module SCM via the Serial Peripheral Interface SPI bus and generates an RF carrier signal at the specified frequency The modulation audio signal from the S...

Page 73: ...receive antenna Filters and dual conversion Outputs a digitized receive signal to the Station Control Module Receiver Module Operation The receive signal is generated from the site receive antenna to a multi pole preselector filter which provides highly selective bandpass filtering The filtered signal is then amplified and fed to the RF input of the 1st mixer The 1st mixer combines the filtered si...

Page 74: ...s External communications is accomplished using a serial port on the top panel The DSP and DSP ASIC perform the necessary digital signal processing for the station audio and data signals The DSP circuitry interfaces with the Receiver Module receive audio the Exciter Module modulation signal and the Wireline Interface Board wireline audio The 2 1 MHz Reference Oscillator generates the reference sig...

Page 75: ...ent mode only and does not perform encryption or decryption of the ASTRO or ASTRO CAI signal SECURENET encoded signals are processed by the ASIC sent to from the microprocessor via the data bus and sent to from the Station Control Module microprocessor via the HDLC bus The station operates in transparent mode only and does not perform encryption or decryption of the SECURENET signal NOTE The WIB i...

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