HARRIS TR-307-X2 PRIVIATE RADIO BASESTATION User Manual LBI 38643C 25 KHZ RECEIVER IF MODULE 19D902783G1

HARRIS CORPORATION PRIVIATE RADIO BASESTATION LBI 38643C 25 KHZ RECEIVER IF MODULE 19D902783G1

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TABLE OF CONTENTSPageDESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Front CoverGENERAL SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1CIRCUIT ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1INPUT MATCHING NETWORK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1CRYSTAL FILTERS, IF AMPLIFIERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1OSCILLATOR/MIXER/DETECTOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1AUDIO AMPLIFIER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1SQUELCH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Buffer Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1High Pass Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Noise Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2DC Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Schmitt Trigger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2FAULT DETECTOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2VOLTAGE REGULATOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2RECOMMENDED TEST EQUIPMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2ALIGNMENT PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3ASSEMBLY DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3OUTLINE DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4SCHEMATIC DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7PRODUCTION CHANGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8IC DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9MAINTENANCE MANUAL FOR25kHz RECEIVER IF MODULE19D902783G1DESCRIPTIONThe MASTR III Receiver IF Module provides ampli-fication and demodulation of the 21.4 MHz IntermediateFrequency signal. The IF Module also includes the re-ceiver squelch circuitry. However, it does not include de-emphasis or squelch audio gating circuits. Figure 1 is ablock diagram showing the functional operation of theIF Module.The IF Module circuitry contains the following:•A 50 ohm input impedance matching network andIF Amplifier•A chain of two crystal filters and two integratedcircuit IF amplifiers•An integrated circuit containing a crystaloscillator, mixer, limiter, and quadrature detector•A variable gain AF amplifier•A squelch circuit•A fault detector circuit•An integrated circuit voltage regulatorLBI-38643CericssonzEricsson Inc.Private Radio SystemsMountain View RoadLynchburg, Virginia 245021-800-528-7711 (Outside USA, 804-592-7711) Printed in U.S.A.

CIRCUIT ANALYSISINPUT MATCHING NETWORKThe input impedance matching network provides a 50 ohmload for the receiver RF module. The network consists of C1thru C3, L1 thru L3, and R1.Capacitor C1 provides AC coupling and a DC block on theinput line (J1). This DC block protects the module in the eventof a failure in a preceding module. L2 and L3 are series reso-nant at 21.4 MHz and provide a signal path to the FET ampli-fier Q6. Parallel resonant circuit, L1 and C2, provide a path tothe 50 ohm load, R1, for frequencies other than 21.4 MHz.CRYSTAL FILTERS, IF AMPLIFIERSY1, Y2, U1, U2, and associated circuitry provide IF filter-ing and amplification at 21.4 MHz. Filters Y1 and Y2 are both4 pole bandpass filters with a center frequency of 21.4 MHzand a bandwidth of ±6.5 kHz. Amplifiers U1 and U2 are inte-grated circuit amplifiers. U1 provides 30 dB of gain, U2 pro-vides 18 dB of gain. The amplifiers and filters have terminalimpedances of 50 ohms. In circuit gain measurements can bemade using a high impedance probe.Inductors L3, L4 and associated resistors and capacitorsprovide power supply decoupling. R3 and R7 provide paths tothe input of the Fault Detector circuit. These inputs enable theFault Detector circuit to monitor the DC voltages of U1 andU2.The RF level detectors consist of transistors Q1 and Q2along with associated resistors and capacitors. These detectorsplay no role in the normal operation of the IF Module, but theyaid in unit testing and module troubleshooting.OSCILLATOR/MIXER/DETECTORIntegrated circuit U3 provides several functions including2nd mixer, if amplifier and limiter, and quadrature detector.The 20.945 MHz crystal oscillator provides local oscillatorinjection to the mixer in U3. This mixer converts the 21.4 MHzIF signal to 455 kHz. C20 and C21 are oscillator feedback ca-pacitors and have been chosen to provide the proper capaci-tance for crystal Y3. The proper oscillator output level isdifficult to measure directly without affecting the oscillation.A preferable measurement is at TP3 which should readabout 50 mV pk. (Measured using a 10 megohm, 11 pF oscil-loscope probe.)The mixer is internally connected to the crystal oscillator.Pins 16 and 3 of U3 are the mixer input and output respec-tively. Typical mixer conversion gain is about 20 dB. The out-put of the mixer drives the 4 pole ceramic bandpass filter FL1.The limiter input is U3 pin 5, but the limiter output is inter-nally connected to the detector and is not externally available.A received signal strength indicator (RSSI) is provided atU3 Pin 13. This indicator signal is generated within the limitercircuitry and provides an output current proportional to thelogarithm of the input signal strength. This current develops avoltage across R18. The voltage varies from about 0.7 Vdc fornoise input, to about 1 Vdc for a 12 dB SINAD signal, to amaximum of about 2.7 Vdc for a high signal level (50 dBstronger than that required for 12 dB SINAD).The quadrature detector provides a demodulated audio fre-quency output. The input to the detector is internally connectedto the limiter and is not externally available. The output of thedetector is U3 pin 9. R19 and C28 provide low-pass filtering toremove 455 kHz feedthrough. Ceramic resonator Y4 providesthe frequency selective component needed for FM demodula-tion. Y4 replaces the typical LC resonant circuit found in mostquadrature detectors. In contrast to the typical LC network, Y4requires no adjustment.The DC supply to U3 is provided through voltage droppingresistor R11 to U3 pin 4. R12 provides a path to the input ofthe Fault Detection circuit. This enables the Fault Detector tomonitor the DC voltage on U3.AUDIO AMPLIFIEROperational amplifier U6.3 provides audio frequency am-plification. Its gain is set by its associated resistors, includingvariable resistor VR1. VR1 allows for adjusting the AF outputlevel to 1 Vrms with a standard input signal to the module (1kHz AF, 3 kHz peak deviation). U6.2 is used as a voltage regu-lator to provide 4 Vdc for biasing the Operational amplifier.SQUELCHBuffer AmplifierIntegrated circuit U6.4 is configured as a unity gain bufferamplifier. It provides a high input impedance to minimize load-ing of the previous circuits.Copyright© February 1992, Ericsson Inc.TABLE 1 - GENERAL SPECIFICATIONSITEM SPECIFICATIONI.F. frequency 21.4 MHzInput Impedance 50 ohm12 dB SINAD -120.0 dBmAdj. CH SEL (25 kHz) -103 dBImage (20.49 MHz) -100 dB3rd order Intercept Pt 23 dBmVariation of Sensitivity with Signal Frequency 2 kHz2nd I.F. frequency 455 kHz2nd L.O. frequency 20.945 MHzAF output (J2 pin 31C) 1 Vrms adjustable (with standard input signal)AF output impedance 1k ohmAF distortion 5%AF response10 Hz -3 dB300 Hz ±1 dB1000 Hz 0 dB reference3 kHz ±1 dBHum & Noise -55 dBRSSI output (J2 pin 20C) 0.7 to 2.7 Vdc prop to log (sig level)RSSI time constant 5 msSQ Threshold Sensitivity -119 dBmSQ Maximum Sensitivity -102 dBmSQ Clipping 3 kHzSQ Attack 150 msSQ Close 250 msSQ output (J2 pin 26C) 5V logic (low = squelched)Fault output (J2 pin 11C) 5V logic (low = fault)DC Supply 1 Vrms (adjustable)LBI-38643C1

Highpass FilterThe audio frequency highpass filter consists of U7.1 and itsassociated circuitry. The purpose of this filter is to reject allvoice frequencies and allow only demodulated noise to pass.The functioning of the squelch circuit depends upon the pres-ence or absence of this noise. (When a signal is being received,i.e. the receiver is quiet, the squelch circuit senses the absenceof noise and unsquelches the radio.)Noise DetectorU7.2 along with associated components act as a noise de-tector. The rectified output of U7.2 charges C44 to a nearlyconstant DC voltage.DC AmplifierU7.3 is configured as a basic amplifier with a gain of 11.Schmitt TriggerU7.4 is configured as an amplifier with positive feedback.This arrangement provides hysteresis in the output verses inputcharacteristic. This eliminates the possibility of the squelch cir-cuit repeatedly cutting in and out when the input signal is neara threshold. R56 and R57 act as a voltage divider to provide a 5volt logic level output. (Logic High = unsqelched)FAULT DETECTORU4 and U5 are voltage comparators. These are configuredinto four "window detectors" which sense the presence of volt-ages within specified ranges (windows).The four window detector circuits are U4.1 & U4.2, U4.4& U4.3, U5.1 & U5.2, and U5.4 & U5.3. These monitor DCoperating voltages on U6.2, U1, U2, and U3 respectively. R29and R30 comprise a voltage divider to provide a 5 volt logiclevel output. A fault is indicated when the output drops to zero.Diode D1 and transistor Q3 monitor the output of the 8Vregulator. D1 is a 8.2 volt breakdown diode. If the regulatoroutput voltage should rise above 8.9 V (8.2 + 0.7 base-emitterdrop) Q1 will turn on and a fault will be indicated.Transistors Q4 and Q5 are drivers for the front panel LEDCR1. These are powered from the +13.8 Vdc line before the8V regulator. Therefore, if the regulator opens, a fault will stillbe indicated.VOLTAGE REGULATORU8 is a monolithic integrated circuit voltage regulator pro-viding 8 Vdc. This powers all circuitry in the module with ex-ception of the front panel LED and its drivers.MAINTENANCERECOMMENDED TEST EQUIPMENTThe following test equipment is required to test the IFModule.1. FM Signal Generator; HP 8640B, HP 8657A, orequivalent2. AF Generator or Function Generator3. Audio Analyzer; HP 8903B, HP 339A, or equivalent4. Oscilloscope5. DC Meter for troubleshooting6. Power Supply; 13.8 Vdc @ 150 mAALIGNMENT PROCEDURE1. Apply 13.8 Vdc supply to module.2. Verify DC current consumption is between 90 and 150mA.3. Verify fault output is 0 to 0.5 Vdc and front panel LEDis off.4. Apply a standard input signal to the module input. (-60dBm, 21.4 MHz signal modulated with 1kHz AF, 3 kHzpeak deviation) 5. Set VR1 for 1 Vrms ±3% at module output (pin 31C on96 pin connector J2).Figure 1 - 25 kHz Receiver IF ModuleLBI-38643C2

TROUBLESHOOTINGEach IF amplifier has a nominal 18 dB gain. U2 has anominal gain of 30 dB. The mixer has about 20 dB gain withproper LO injection. The proper crystal oscillator level is 50mV pk measured at TP3.The following four test points are provided on the PWB foradditional test capability:TP1: 100 mV pk @ 21.4 MHz with -30 dBm input sig-nalTP2: 100 mV PK @ 21.4 MHz with -50 dBm inputsignalTP3: 50 mV pk @ 20.945 MHz independent of inputsignalTP4: 100 mV pk @ 455 kHz with -60 dBm input sig-nalAll RF voltages measured with 10 Megohm, 11 pF probe.ASSEMBLY DIAGRAMTROUBLE SHOOTING GUIDESYMPTOM CHECK (CORRECT READING SHOWN) INCORRECT READING INDICATES DEFECTIVE COMPONENTFault indicator on Check DC voltages+8V at U8 Pin 1+4v at U Pin 75.5V at U1 output pin3.3V at 2 output pin4.4V at U3 Pin 4If DC voltages not correctU8 or associated componentsU6 or associated componentsU1 or associated componentsU2 or associated componentsU3 or associated componentsIf DC voltages correctU4, U5, U6, D1, Q3, Q4, Q5No audio - nonoise With no signal applied to module IF inputCheck for AF noise @ C29 ; 200mVCheck for AF noise @ U6 Pin 8: 1 V U3 or associated componentsU6 or associated componentsNoise only - nodemodulated audio Check crystal oscillator: TP3 50 mVpk 20.945 MHzApply -30 dBm 21.4 MHz input, check TP1 100 mVpkApply -50 dBm 21.4 MHz input, check TP2 100 mVpkApply -60 dBm 21.4 MHz input, check TP4 100 mVpkU3, Y3 or associated componentsQ6, Y1, U1 or associated componentsU2, Y2 or associated componentsU3, FL1 or associated componentsPoor 12 dB SINAD Check crystal oscillator: TP3 50 mVpk 20.945 MHz U3, Y3 or associated componentsApply -30 dBm 21.4 MHz input, check TP1 100 mVpkApply -50 dBm 21.4 MHz input, check TP2 100 mVpkApply -60 dBm 21.4 MHz input, check TP4 100 mVpkQ6, Y1, U1 or associated componentsU2, Y2 or associated componentsU3, FL1 or associated componentsNo squelch function With squelch pot maximum, or with module AUDIO/SQUELCH/HI connected to SQUELCH/ARM inputand with no signal to module IF input:Check Presence of 1 Vpk noise at U6 Pin 14 U6 or associated componentsCheck presence of 1 Vpk noise U7 at Pin 1Check presence of 1 Vpk noise U7 Pin 1Check DC voltage U7 at Pin 8: 7 VCheck DC voltage U7 Pin 14: 0.5 V U7 or associated componentsRECEIVER IF MODULE19D902783G1(19D902783, Sh. 1, Rev. 3)LBI-38643C3

RECEIVER IF MODULE19D902494G1OUTLINE DIAGRAM(19D902494, Sh. 1, Rev. 5B)(19D902493, Comp. Side, Rev. 5)LBI-38643C4

SCHEMATIC DIAGRAMRECEIVER IF MODULE19D902494G1(19D902504, Sh. 1, Rev. 6) LBI-38643C5

SCHEMATIC DIAGRAMRECEIVER IF MODULE19D902494G1(19D902504, Sh. 2, Rev. 6)LBI-38643C6

PARTS LIST & PRODUCTION CHANGESPRODUCTION CHANGESChanges in the equipment to improve performance or to simplify circuits areidentified by a "Revision Letter" which is stamped after the model number of theunit. The revision stamped on the unit includes all previous revisions. Refer tothe Parts List for the descriptions of parts affected by these revisions.Rev. A - 19D902494G1, 25 kHz IF Module BoardTo improve performance in high temperature environments and toeliminate Audio Level drifting, changed voltage regulator U8 and vari-able resistor VR1.U8 was: 19A704971P11, 8 Vdc; sim to MC78L08ACD.VR1 was: 19A705496P5 20K ohms 0.1w; sim to Murata RGV4E203.Rev. B - 19D902494G1, 25 kHz IF Module BoardTo change Squelch Driver operation to allow compatibility with GETC,changed resistors R56, R57, and R69.R56 was: 19B800607P182 Metal film: 1.8K ohms ±5%, 1/8 w.R57 was: 19B800607P822 Metal film: 8.2K ohms ±5%, 1/8 w.R69 was: 19B800607P102 Metal film: 1K ohms ±5%, 1/8 w.SYMBOL PART NO. DESCRIPTION- - - - - - - - - - -CRYSTALS - - - - - - - - -Y1 19A149974G7 Filter, crystal: Fc = 21.4 MHz, 3 dB BW =15.0 kHz. Insertion loss = 2.0 dB max.Y2 19A149974G8 Filter, crystal: Fc = 21.4 MHz, 3 dB BW =15.0 kHz. Insertion loss = 3.0 dB max.Y3 19A702284G5 Quartz crystal unit: 20.945000 MHz ±10 ppm@ 25°C.Y4 19A149976P1 Fixed: 455 kHz.LBI-38643C8

IC DATAU4 & U519A704125P1Quad ComparatorU6 & U719A701789P4Quad Op-AmpU819A704971P10Voltage RegulatorU319A149980P2FM ReceiverU1344A3740P1Silicon Bipolar ICU219A705927P1Silicon Bipolar ICLBI-38643C9

ASSEMBLY DIAGRAMMAINTENANCE MANUALFORUHF TRANSMITTER SYNTHESIZER MODULE19D902780G3, G6 - G10LBI-38671HTABLE OF CONTENTSPageDESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1GENERAL SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1CIRCUIT ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1VOLTAGE CONTROLLED OSCILLATOR . . . . . . . . . . . . . . . . . . . . . . . . . . . 1FREQUENCY DOUBLER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1RF AMPLIFIERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1REFERENCE BUFFER AMPLIFIER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1PRESCALER AND SYNTHESIZER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2LOOP BUFFER AMPLIFIERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2AUDIO FREQUENCY AMPLIFIER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2VOLTAGE REGULATORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2LOGIC CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3TEST PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3ALIGNMENT PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4PRODUCTION CHANGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6IC DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6OUTLINE DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8SCHEMATIC DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9ASSEMBLY DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Back CoverEricsson Inc.Private Radio SystemsMountain View RoadLynchburg, Virginia 245021-800-528-7711 (Outside USA, 804-592-7711) Printed in U.S.A.EUHF TRANSMITTERSYNTHESIZER MODULE19D902780G3, G6 - G10(19D902780, Sh. 1, Rev. 5)

DESCRIPTIONThe principle function of the Transmitter Synthesizer Moduleis to provide the RF excitation for input to the MASTR IIIstation power amplifier. The output of the synthesizer is afrequency modulated signal at the desired frequency. The mod-ule contains the following functional blocks:•A voltage controlled oscillator.•Frequency Doubler (Multiplier).•A chain of integrated circuit RF Amplifiers.•A reference buffer amplifier.•Dual modulus prescaler and synthesizer integratedcircuits.•Loop amplifiers and passive loop filter.•An audio amplifier and a pre-modulation integrator.•IC voltage regulators for +5 and -5 Vdc. A discretecomponent regulator for +8 Vdc, and an Opera-tional Amplifier regulator for +4 Vdc.•Logic circuitry: address decoder, input signal gates,and a lock indicator circuit.CIRCUIT ANALYSISVOLTAGE CONTROLLED OSCILLATORTransistor Q1 and associated circuitry comprise a low noiseVoltage Controlled Oscillator (VCO). Inductor L1 and asso-ciated capacitors form the oscillator resonant circuit (tank).The noise characteristic of this oscillator is dependent on theQ of this resonant circuit. The components used in the tankare specified to have especially high Q. Diode D1 aids insetting the bias point for low noise operation. (Any fieldreplacement of oscillator parts should use identical parts).Variable Capacitor C10 sets the fixed capacitance in the tank,and therefore sets the frequency range over which the oscil-lator can be voltage tuned.The oscillator frequency is voltage tuned by the signal ap-plied through R5 and L5 to the two varicap diodes D2 andD3. Additionally, audio modulation is applied as an AFvoltage to the two varicap diodes. This RF voltage varies theoscillator frequency at an audio rate (i.e., it frequency modu-lates the oscillator). Low frequency audio is applied alongwith the varicap control voltage through R5 and L5 whilehigh frequency audio (MOD) is applied via C16.Resistors R6 through R9 provide a two volt negative bias onthe varicap diodes.Transistors Q101 and Q102 and associated circuitry form theoscillator enable switch. This switch allows the station con-trol circuitry to turn the VCO ON or OFF via the ANT_RELline. Setting the ANT_REL line to a logic low causes Q102to conduct. The five (5) volt output at Q102 collector(OSCON) enables the fault indicator gates, U705-3 andU705-4, and turns on Q101. Q101 starts to conduct, provid-ing a ground path for Q1. This turns ON the VCO.FREQUENCY DOUBLERTransistors Q801 and Q802 form a buffer stage to drivetransistor multiplier Q803. The buffer isolates VCO Q1 fromloading effects which could degrade oscillator loaded Q andhence noise performance. Transistor multiplier Q803 istuned to pass the second harmonic of the VCO output andserves as a frequency doubler. Tank elements L802, C812-C814 and L803 form a resonant circuit and matching net-work to drive resistive splitter R201-R204.RF AMPLIFIERSThe RF chain begins with resistive splitter R201-R204 andR216-R218. The output of the splitter at R203 is attenuatedby 10 dB and provides impedance matching helical filterFL201, which is tuned to pass the fundamental while reject-ing harmonics by approximately 40 dB. The output of FL201is fed thru resistive pad R205-R207 to MMIC AmplifierU201 which operates in compression. U201 drives outputamplifier U202 into compression. The output amplifier isfollowed by a bandpass filter (C208-C210, L203-L205) andresistive attenuators (R210-R215). The final output at thefront panel BNC Connector (J2) is nominally 11.5 dBm, anddrives the station Power Amp.The other output of the resistive splitter at R218 is attenuatedby 20 dB and drives buffer amp U203 into compression.U203 drives the synthesizer prescaler providing a feedbacksignal for the synthesizer phase locked loop.REFERENCE BUFFER AMPLIFIERTransistor Q401 and associated components comprise a buff-er amplifier for the reference oscillator signal. (The referenceoscillator signal is produced by the receiver synthesizermodule of a MASTR III station.) The 0 dBm referenceoscillator signal is fed through the front panel BNC connec-tor J1. Resistor R405 provides a 50 ohm load to the referenceoscillator. The output of the Reference Buffer Amplifier isfed directly to the synthesizer integrated circuit. The outputlevel at TP9 is approximately 3 volts peak to peak.Copyright © June 1992, Ericsson GE Mobile Communications, Inc.TABLE 1 - GENERAL SPECIFICATIONSITEM SPECIFICATIONFREQUENCY RANGE 450-470 MHz (G3)425-450 MHz (G7)403-430 MHz (G6)380-400 MHz (G8)470-494 MHz (G9)490-512 MHz (G10)CHANNEL SPACING 6.25 kHzRF POWER OUT (50 Ohm load) 10 to 13 dBm(10 to 20 mW)RF HARMONICS < -30 dBcNON-HARMONIC SPURS1 to 200 MHz < - 90 dBc200 MHz to 1 GHz < - 60 dBcCARRIER ATTACK TIME <25 mSecREFERENCE INPUTinput level 0 dBm ±1.5dBinput impedance 50 Ohmfrequency 5 to 17.925 MHz (must be integer divisible by channel spacing)MODULATION SENSITIVITY 5 kHz peak dev/1 Vrms, AdjustableAF INPUT IMPEDANCE 600 OhmAF RESPONSE10 Hz ±1.5 dB1000 Hz0 dB reference3 kHz ±1.5 dB10 Hz SQUARE WAVE MODULATION <10%Sq wave droopHUM & NOISE -55 dBPOWER REQUIREMENTS 13.8 Vdc @ 275 mA-12.0 Vdc @ 10 mAThis manual is published by Ericsson Inc., without any warranty. Improvements and changes to this manual necessitated by typographical errors, inaccuracies of current information, or improvements to programsand/or equipment, may be made by Ericsson Inc., at any time and without notice. Such changes will be incorporated into new editions of this manual. No part of this manual may be reproduced or transmitted in anyform or by any means, electronic or mechanical, including photocopying and recording, for any purpose, without the express written permission of Ericsson Inc.LBI-38671H1

PRESCALER AND SYNTHESIZERIntegrated circuit U402 is the heart of the synthesizer. Itcontains the necessary frequency dividers and control cir-cuitry to synthesize output frequencies by the technique ofdual modulus prescaling. U402 also contains an analogsample and hold phase detector and a lock detector circuit.Within the synthesizer (U402) are three programmable di-viders which are loaded serially using the CLOCK, DATA,and ENABLE inputs (pins 11, 12, and 13 respectively). Aserial data stream (DATA) on pin 12 is shifted into internalshift registers by low to high transitions on the clock input(CLOCK) at pin 11. A logic high (ENABLE) on pin 13 thentransfers the program information from the shift registers tothe divider latches.The reference signal is applied to U402 pin 2 and divided bythe "R" divider. This divides the reference signal down to adivided reference frequency (Fr). The typical reference fre-quency is 12.8 MHz and the typical divided reference fre-quency is 6.25 kHz providing for synthesizer steps of 6.25kHz for use with both 12.5 kHz and 25 kHz channel spacing.Other channel spacings are possible by providing properprogramming.The "A" and "N" dividers process the loop feedback signalprovided by the VCO (by way of the dual modulus prescalerU401). The output of the "N" divider is a divided version ofthe VCO output frequency (Fv).Synthesizer U402 also contains logic circuitry to control thedual modulus prescaler U401. If the locked synthesizeroutput frequency is 450 MHz. The prescaler output nomi-nally will be equal to 3.515625 MHz (450 MHz/128). Thisfrequency is further divided down to Fv by the "N" dividerin U402. Fv is then compared with Fr in the phase detectorsection.The phase detector output voltage is proportional to thephase difference between Fv and Fr. This phase detectoroutput serves as the loop error signal. This error signalvoltage tunes the VCO to whatever frequency is required tokeep Fv and Fr locked (in phase).LOOP BUFFER AMPLIFIERS AND LOOP FILTERThe error signal provided by the phase detector output isbuffered by operational amplifiers (op-amp) U501A andU501B. The audio modulation signal from U601B is alsoapplied to the input of U501B. The output of U501B is thesum of the audio modulation and the buffered error signal.The output of the second buffer (U501B) is applied to a loopfilter consisting of R506, R507, R508, C505 and C506. Thisfilter controls the bandwidth and stability of the synthesizerloop. The UHF transmitter synthesizer has a loop bandwidthof only several Hertz. This is very narrow, resulting in anexcessively long loop acquisition time. To speed acquisition,switches U502A and U502C bypass the filter circuit when-ever an ENABLE pulse is received by the Input Gates.AUDIO FREQUENCY AMPLIFIERThe transmitter synthesizer audio input line is fed to U601A.U601A is configured as a unity gain op-amp. Resistor R601sets the 600 ohm input impedance of this amplifier. (NOTE:Data for digital modulation is fed to the synthesizer throughthe audio input line).The amplifier output is split into two components and fed totwo variable resistors VR601 and VR602. VR601 sets thelevel in the low frequency audio path and VR602 sets thelevel in the high frequency audio path. (There is no clearbreak between the low and high frequency ranges. All voicefrequencies are within the high frequency range. The lowfrequency range contains low frequency data components).The wiper of VR601 (low frequency path) connects to theinput of U601B, the pre-modulation integrator. U601B per-forms the function of a low-pass filter and integrator. Theintegrator output is summed with the PLL control voltage atthe input of loop buffer amplifier U501B. This integratedaudio signal phase modulates the VCO. The combination ofpre-integration and phase modulation is equivalent to fre-quency modulation.The wiper of VR602 (high frequency path) is connected tothe modulation input of the VCO through C16.VOLTAGE REGULATORSU301 and U303 are monolithic voltage regulators (+5 Vdcand -5 Vdc respectively). These two voltages are used bysynthesizer circuitry. The +5 V regulator output is also usedas a voltage reference for the +8 Vdc discrete regulatorcircuit.U302A, Q302 and associated circuitry comprise the +8 voltregulator. Most module circuitry is powered from the +8 voltline. The regulator is optimized for especially low noiseperformance. This is critical because the low noise VCO ispowered by the +8 volt line.The +8 Vdc line also feeds the +4 Vdc regulator, U302B andassociated resistors. The +4 Vdc regulator provides a biasvoltage for several op-amps in the module.Figure 1 - Block DiagramLBI-38671H2

LOGIC CIRCUITSLogic circuitry (other than that inside the synthesizer IC -U402) consists of the following:•An address decoder•Input gates and level shifters•Lock Indicator circuitryThe address decoder, U702, enables the Input Gates when theA0, A1, and A2 input lines receive the proper logic code (110for the transmitter synthesizer). After receiving the propercode, Y3 (U702-12) sends a logic low signal to U701C. U701Cacts as an inverter and uses the logic high output to turn onInput Gates U701A, U701B, and U701D. The Input Gatesallow the clock, data and enable information to pass on to thesynthesizer via the level shifters. The Level Shifter TransistorsQ701, Q702 and Q703 convert the 5 volt gate logic level to the8 volt logic level required by the synthesizer U402.The Fault Indicator circuitry indicates when the synthesizer isin an out-of-lock condition. The fault detector latches, U705Aand U705B are reset by the enable pulse during initial loadingof data into the synthesizer. If at any time afterwards the lockdetector signal (LD) goes low, the high output of U705B willcause the output of gates U705C and U705D to go low. Thelow output from U705C causes Q704 to conduct turning on thefront panel LED (CR701). The output of U705D (FLAG) isconnected to J3-13C for external monitoring of the SynthesizerModule. A logic low on the FLAG line indicates an out-of-lockcondition.MAINTENANCERECOMMENDED TEST EQUIPMENTThe following test equipment is required to test the synthesizerModule:1. RF signal source for 12.8 MHz, 0 dBm reference (in-cluded with item 10)2. AF Generator or Function Generator3. Modulation Analyzer; HP 8901A, or equivalent, or aUHF receiver4. Oscilloscope; 20 MHz5. DC Meter; 10 meg ohm (for troubleshooting)6. Power Supply; 13.8 Vdc @ 350 mA12.0 Vdc @ 25 mA7. Spectrum Analyzer; 0-1 GHz8. Frequency Counter; 10 MHz - 500 MHz9. Personal Computer (IBM PC compatible) to load fre-quency data10. Service Parts Kit, (TQ-0650), (includes software forloading frequency data)TEST PROCEDURE(Steps 5, 6, and 7 can be done using a modulation analyzeror UHF receiver with 750 µs de-emphasis switchable in orout.1. Lock synthesizer at 470.0 (G3), 430 (G6), 450 (G7),400 (G8), 494 (G9) or 512 (G10) MHz using softwareprovided in the service parts kit.Verify lock (flag = high).Verify front panel LED is off.2. Measure output frequency.Verify frequency = 470.0000 (G3), 425.000(G6) or 450.000 (G7) MHz, 400.000 (G8),494.000 (G9) or 512.000 (G10) ±200 Hz.3. Measure harmonic content.Verify 2nd harmonic is < -30 dBc.4. Measure RF power output into 50 ohm load.Verify 10 to 13 dBm (10 to 20 mW).5. Measure AF distortion with standard modulating sig-nal input.Verify <2.5%.6. Measure Hum and Noise relative to 0.44 kHz averagedeviation, (de-emphasis on).Verify < -55dB7. Measure AF response at 300 Hz, 1 kHz (ref) and 3kHz, (de-emphasis off).Verify within ±1.5 dB with respect to 1 kHzreference.8. Verify lock at different frequencies.a. Lock synthesizer at 380 (G8), 450 (G3), 403(G6), 425 (G7), 470 (G9) or 492 (G10) MHz.Verify LED is off.b. Lock synthesizer at 385 (G8), 455 (G3), 408.5(G6), 430 (G7), 476 (G9) or 497 (G10) MHz.Verify LED is off.c. Lock synthesizer at 395 (G8), 465 (G3), 419.5(G6), 445 (G7), 488 (G9) or 507 (G10) MHz.Verify LED is off.d. Lock synthesizer at 400 (G8), 470 (G3), 425(G6), 450 (G7), 494 (G9) or 512 (G10) MHz.Verify LED is off.ALIGNMENT PROCEDURE1. Apply +13.8 Vdc and -12 Vdc. Verify the currentdrain on the 13.8 volt supply is, <300mA and thecurrent drain on the -12 volt supply is <20 mA.2. Lock the synthesizer at 380 (G8), 450 (G3), 403 (G6),425 (G7), 470 (G9) or 492 (G10) MHz. Adjust trim-mer C1O until Vtest (23A) reads 2.5 (G3, G8), 2.0(G6, G7, G9) or 3.0 (G10) V ±0.05V.3. Lock synthesizer at 460.0 (G3), 390.0 (G8), 414 (G6)or 437.5 (G7), 482 (G9) or 502 (G10) MHz for thefollowing three adjustments.•Set VR602 for 4.5 kHz peak deviation with a stand-ard modulating signal applied to the audio input.•Set VR601 for 4.5 kHz peak deviation with 1.0Vrms, 10 Hz (or 7 Hz for G3) sine wave audioapplied to module AF input.•Apply a 10 Hz 1.4 Vpk square wave to module AFinput. Adjust VR601 slightly for the flattest de-modulated square wave using a modulation ana-lyzer or receiver (no de-emphasis) and anoscilloscope. The maximum net variation in voltageover 1/2 cycle is 5%.TROUBLESHOOTINGA troubleshooting guide is provided showing typical meas-urements at the various test points.This adjustment is critical for EDACS applicationand must be reset at customer frequency.NOTESERVICE NOTESThe following service information applies whenaligning, testing, or troubleshooting the TX Synthe-sizer:•Standard Modulating Signal = 1 kHz sinusoidalvoltage, 0.6 Vrms at the module input terminals(600 ohm Rin).•Logic Levels:Logic 1 = high = 4.5 to 5.5 VdcLogic 0 = Low = 0 to 0.5 Vdc•Transmitter Synthesizer Address = A0 A1 A2 =110•Synthesizer data input stream is as follows:14-bit "R" divider most significant bit(MSB) = R13 through "R" divider least sig-nificant bit (LSB) = R010-bit "N" divider MSB = N9 through "N"divider LSB = N07-bit "A" divider MSB = A6 through "A"divider LSB = A0Single high Control bit (last bit)Latched When Control Bit = 1DATA ENTRY FORMATLatched WhenControl Bit = 1Data in ➞Last A0 A6 N0 N9 R0 R13 ➞Bit LSB – – – – – MSB LSB – – – – MSB LSBFor the transmitter synthesizer, 5 kHz chan-nel spacingR = 2560N = integer part of (frequency in kHz)/(320)A = (frequency in kHz)/(5) - 64*NAll numbers must be converted to binary.•ANT_REL line must be logic low (0V) in order tolock synthesizer.•Synthesizer lock is indicated by the extinguishingof the front panel LED indicator and a logic highon the fault flag line (J3 pin 13C).•Always verify synthesizer lock after each new dataloading.Control BLBI-38671H3

PARTS LISTSYMPTOM CHECK(CORRECT READINGS SHOWN) INCORRECT READING INDICATESDEFECTIVE COMPONENTSYNTHESIZER FAILS TO LOCK Check DC voltages +5 V @ U301 Pin 1 +8 V @ Q301 collector -5 V @ U303 Pin 1U301 or associated componentsU302, Q301, Q302 or associatedcomponentsU303 or associated componentsCheck 12.8 MHz reference signal3V P-P, 12.8 MHz @ U402 Pin 2 No reference signal to front panel BNC orQ401Check oscillator signal 11.5 ±1.5 dBm 435 to 485 MHz at front panel BNCProceed to "Low/No RF output" belowCheck prescaler output IV P-P, 3.5 MHz @ U401 Pin 4 U202, U401Check CLOCK, DATA, ENABLE While loading frequency data into synthesizer Check 8V logic signals@ Pins 11, 12, 13 of U402Wrong address or U701, U702, Q701, Q702, Q703Check Phase detector output 6.25 kHz random signal @ U501Pin 7 U402, U501Low/No RF Output Check oscillator LESS than 0.5 Vdc @ collector of Q101 Synthesizer not keyed (low on ANT relayline) or Q101, Q102Check RF chainNo Modulation Check AF amplifierApply IV, 1 kHz signal toTX/Audio/Hi U601Check IV signal @ U601 Pin 1TROUBLESHOOTING GUIDE UHF TRANSMITTER SYNTHESIZER MODULE19D902780G3, G6 - G10ISSUE 9*COMPONENTS, ADDED, DELETED OR CHANGED BY PRODUCTION CHANGESSYMBOL PART NO. DESCRIPTIONTRANSMITTER SYNTHESIZER BOARD19D902779G3, G6 - G10- - - - - - - - - MISCELLANEOUS - - - - - - - - -2 19D902508P4 Chassis.3 19D902509P2 Cover.4 19D902555P1 Handle.6 19A702381P506 Screw, thread forming: TORX, No. M3.5-.6 x 6.7 19A702381P513 Screw, thread forming: TORX, No. M3.5 - 0.6 X 13.11 19A702381P508 Screw, thd. form: No. 3.5-0.6 x 8.12 19D902824P1 Casting.- - - - - - - - - - CAPACITORS - - - - - - - - -C1 19A702236P25 Ceramic: 10 pF + or -.5 pF, 50 VDCW, temp coef+ or -30 PPM/°C.C2 19A702236P32 Ceramic: 18 pF + or -5%, 50 VDCW, temp coef 0 ++ or or -30 PPMC3 19A702236P28 Ceramic: 12 pF + or - 5%, 50 VDCW, temp coef 0+ or -30 PPM.C4 19A702236P1 Ceramic: 0.5 pF + or - pF, temp coef 0+ or - PPM/°C. (Used in G8).C4 19A702236P8 Ceramic: 1.5 pF + or -.25 pF, 50 VDCW.(Used in G3, G6, G7)C4andC519A702236P17 Ceramic: 4.7 pF + or -0.5%, 50 VDCW, temp coef 0+ or -60 PPM. (Used in G9).C4 19A702236P11 Ceramic: 2.7 pF + or - .25 pF, 50 VDCW, temp coef 0+ or -30 PPM/°C. (Used in G10).C5 19A702236P17 Ceramic: 4.7 pF + or -5%, 50 VDCW, temp coef 0+ or -30 PPM. (Used in G3 & G10).C5 19A702236P17 Ceramic: 4.7 pF + or -5%, 50 VDCW, temp coef 0+ or -30 PPM. (Used in G6 & G8).C5 19A702236P15 Ceramic: 3.9 pF + or -.25 pF, 50 VDCW, temp+ or -30 PPM/°C. (Used in G7).C6 19A702236P28 Ceramic: 12 pF + or - 5%, 50 VDCW, temp coef 0+ or -30 PPM. (Used in G8 & G3).C6 19A702236P30 Ceramic: 15 pF + or -5%, 50 VDCW, temp coef 0 +or -30 PPM/°C. (Used in G6 & G7).*C6 19A702236P28 Ceramic: 12 pF + or -5%, 50 VDCW, temp coef 0+ or -30 PPM/°C. (Used in G9 & G10).C7 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0+ or -30 PPM/°C.C8 19A702052P14 Ceramic: 0.01 uF + or - 10%, 50 VDCW.C9 19A705205P6 Tantalum: 10 uF, 16 VDCW; sim to Sprague 293D.C10 19A134227P5 Variable: 1.5 to 14 pF, 100 VDCW.C11 19A705205P2 Tantalum: 1 uF, 16 VDCW; sim to Sprague 293D.C12 19A702052P14 Ceramic: 0.01 uF + or - 10%, 50 VDCW.C13 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0and + or -30 PPM/°C.C14*C15 19A700004P6 Metallized polyester: 4.7 uF + or - 10%, 63 VDCW.*C16 19A702052P106 Ceramic: 1500 pF + or -5%, 50 VDCW.C17 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0+ or -30 PPM/°C.C18 19A705205P2 Tantalum: 1 uF, 16 VDCW; sim to Sprague 293D.andC19C101 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0+ or -30 PPM/°C.C102 19A705205P2 Tantalum: 1 uF, 16 VDCW; sim to Sprague 293D.C103 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0+ or -30 PPM/°C.SYMBOL PART NO. DESCRIPTIONC201 19A702061P61 Ceramic: 100 pF + or - 5%, 50 VDCW, temp coef 0+ or - 30 PPM. C202 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0+ or -30 PPM/°C.C203 19A705205P2 Tantalum: 1 uF, 16 VDCW; sim to Sprague 293D.C204 19A702061P61 Ceramic: 100 pF + or - 5%, 50 VDCW, temp coef 0and + or - 30 PPM.C205C206 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0+ or -30 PPM/°C.C207 19A705205P2 Tantalum: 1 uF, 16 VDCW; sim to Sprague 293D.C208 19A702236P28 Ceramic: 12 pF + or - 5%, 50 VDCW, temp coef 0+ or -30 PPM.C209 19A702236P10 Ceramic: 2.2 pF + or -2.5 pF, 50 VDCW, temp+ or -30 PPM/°C. (Used in G3, G6, G7, G8).C209 19A702236P8 Ceramic: 1.5 pF + or -0.25 pF, 50 VDCW, temp+ or -30 PPM/°C. (Used in G9 & G10).C210 19A702236P28 Ceramic: 12 pF + or - 5%, 50 VDCW, temp coef 0+ or -30 PPM.C211 19A702061P61 Ceramic: 100 pF + or - 5%, 50 VDCW, temp coef 0and + or - 30 PPM.C212C213 19A705205P2 Tantalum: 1 uF, 16 VDCW; sim to Sprague 293D.C214 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0+ or -30 PPM/°C.C215 19A702061P61 Ceramic: 100 pF + or - 5%, 50 VDCW, temp coef 0+ or - 30 PPM.C301 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0+ or -30 PPM/°C.C302 19A702052P14 Ceramic: 0.01 uF + or - 10%, 50 VDCW.C303 19A705205P2 Tantalum: 1 uF, 16 VDCW; sim to Sprague 293D.andC304C305 19A705205P7 Tantalum: 10 uF, 25 VDCW; sim to Sprague 293D.C306 19A705205P2 Tantalum: 1 uF, 16 VDCW; sim to Sprague 293D.C307 19A705205P6 Tantalum: 10 uF, 16 VDCW; sim to Sprague 293D.C308 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0and + or -30 PPM/°C.C309C310 19A705205P6 Tantalum: 10 uF, 16 VDCW; sim to Sprague 293D.C311 19A705205P2 Tantalum: 1 uF, 16 VDCW; sim to Sprague 293D.C312 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0+ or -30 PPM/°C.C313 19A705205P6 Tantalum: 10 uF, 16 VDCW; sim to Sprague 293D.C401 19A702052P14 Ceramic: 0.01 uF + or - 10%, 50 VDCW.C402 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0+ or -30 PPM/°C.C403 19A702052P14 Ceramic: 0.01 uF + or - 10%, 50 VDCW.thruC405C406 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0+ or -30 PPM/°C.C407 19A702052P14 Ceramic: 0.01 uF + or - 10%, 50 VDCW.C408 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0+ or -30 PPM/°C.C409 19A705205P6 Tantalum: 10 uF, 16 VDCW; sim to Sprague 293D.C410 19A702052P26 Ceramic: 0.1uF + or - 10%, 50 VDCWC411 19A705205P6 Tantalum: 10 uF, 16 VDCW; sim to Sprague 293D.C412 19A702052P14 Ceramic: 0.01 uF + or - 10%, 50 VDCW.C413 19A702052P108 Ceramic: 0.01 uF + or -10%, 50 VDCW.C414 19A702061P69 Ceramic: 220 pF + or -5%, 50 VDCW, temp coef 0+ or -30 PPM/°C.C501 19A705205P2 Tantalum: 1 uF, 16 VDCW; sim to Sprague 293D.C502 19A705205P2 Tantalum: 1 uF, 16 VDCW; sim to Sprague 293D.C503 19A702052P33 Ceramic: 0.1 uF + or -10%, 50 VDCW.LBI-38671H4

PRODUCTION CHANGES & IC DATAU30119A704971P9+5V RegulatorU302 & U60119A116297P7Dual Wide Band Op-AmpU202344A3907P1Silicon Bipolar MMICU30319A704971P7-5V regulatorU501344A3070P1Operational AmplifierPRODUCTION CHANGESChanges in the equipment to improve or to simplify circuits are identified by a"Revision Letter", which is stamped after the model number of the unit. Therevision stamped on the unit includes all previous revisions. Refer to the PartsList for descriptions of parts affected by these revisions.REV. A - TRANSMITTER SYNTHESIZER BOARD 19D902779G3,6,7To correct loading problem on synth IC which could cause failure to lockon channel. R707 was 47k ohms (19B800607P473).REV. B - TRANSMITTER SYNTHESIZER BOARD 19D902779G3, G6-G7REV. A - TRANSMITTER SYNTHESIZER BOARD 19D902779G8To make new band splits compatible with helical filters. New PWB.C15 was 0.1 µF (19A700004P2).C16 was 330 pF (19A702061P73).REV. A - TRANSMITTER SYNTHESIZER BOARD 19D902779G9REV. B - TRANSMITTER SYNTHESIZER BOARD 19D902779G8REV. C - TRANSMITTER SYNTHESIZER BOARD 19D902779G3, G6, G7To meet hum & noise performance.R101 was 47K ohm (19B800607P473).C16 was 1500 pF (19A702061P89).R9 was 680 ohm (19B800607P681) for G9.R211 was 15 ohm (19B800607P150) for G9.R214 was 15 ohm (19B800607P150) for G9.R507 was 27K ohm (19B800607P150) for G9.C5 was 3.9 pF (19A702236P15) for G9.C6 was 18 pF (19A702236P32) for G9.PWB was R1 return to R0.REV. D - TRANSMITTER SYNTHESIZER BOARD 19D902779G3To improve performance, C5 was 3.3 pF (19A702236P13).REV. D - TRANSMITTER SYNTHESIZER BOARD 19D902779G6To improve VCO tuning range, R9 was 680 ohms (19B800607P681).REV. C - TRANSMITTER SYNTHESIZER BOARD 19D902779G8To improve output level a wire was soldered between pins 3 and 4 andbetween pins 9, 10 and 17 of FL101.REV. A - TRANSMITTER SYNTHESIZER BOARD 19D902779G10Adjust tuning range, C4 changed from 4.7 pF (19A702236P17) to 2.7pF (19A702236P11).U201 and U20319A705927P11Silicon Bipolar MMICLBI-38671H6

IC DATAU40119A149944P201Dual Modulus PrescalerU40219B800902P5SynthesizerU50219A702705P4Quad Analog SwitchU701 & U70519A703483P302Quad 2-Input NAND GateU70219A703471P120Address DecoderLBI-38671H7

OUTLINE DIAGRAMUHF TRANSMITTERSYNTHESIZER BOARD19D902779G3, G6 - G10SOLDER SIDECOMPONENT SIDE(19D902779, Sh. 2, Rev. 9)(19D903361, Layer 1 & 4, Rev. 0)LBI-38671H8

SCHEMATIC DIAGRAMUHF TRANSMITTER SYNTHESIZER19D902780G3, G6 - G10(19D903363, Sh. 1, Rev. 10)LBI-38671H9

SCHEMATIC DIAGRAMUHF TRANSMITTER SYNTHESIZER19D902780G3, G6 - G10(19D903363, Sh. 2, Rev. 10)LBI-38671H10

SCHEMATIC DIAGRAMUHF TRANSMITTER SYNTHESIZER19D902780G3, G6 - G10(19D903363, Sh. 3, Rev. 10)LBI-38671H11

MAINTENANCE MANUALFORUHF RECEIVER SYNTHESIZER MODULE 19D902781G3, G7, G8, G10, G12LBI-38672JDESCRIPTIONThe Receiver Synthesizer Module, 19D902781G3, G7,G8, G10 or G12 provides the local oscillator signal (LO) tothe Receiver Front End Module of the MASTR III basestation. The module also provides the reference oscillatorsignal to the transmitter synthesizer.Figure 1 is a block diagram of the Receiver SynthesizerModule. The synthesizer is connected in a phase-locked loop(PLL) configuration. The synthesizer°s output is generatedby the VCO, Q1, and multiplier Q16. It°s then buffered bythe Monolithic Microwave Integrated Circuit (MMIC) U2.The logic signals from the controller (U10, U12, andU13) control the synthesizer frequency. Frequency stabilityis maintained by using either the internal reference oscillatorY1 or applying an external high precision reference signalto the EXT Reference Oscillator Port J4. The internal refer-ence oscillator, Y1, is a temperature controlled crystal oscil-lator (TCXO) operating at 12.8 MHz. The oscillator has astability of ±1.0 ppm over the temperature range of -30°C to+75°C.The multiplier output is sampled by the resistive splitterand conditioned by buffer amplifier U3. It is then fed to thedivide by 128/129 dual modulus prescaler U5. The dividedoutput from the prescaler is connected to the Fin input of thePLL U6. Within the PLL the divided multiplier input signalFin is divided again. The PLL also divides down the 12.8MHz reference signal. Three inputs from the controller;ENABLE, CLOCK, and serial DATA program the PLL di-vider circuits.Ericsson Inc.Private Radio SystemsMountain View RoadLynchburg,Virginia 245021-800-528-7711(Outside USA, 804-592-7711) Printed in U.S.A.TABLE OF CONTENTSPageDESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Front CoverGENERAL SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1CIRCUIT ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2VOLTAGE CONTROLLED OSCILLATOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2FREQUENCY DOUBLER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2RF AMPLIFIERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2REFERENCE OSCILLATOR AND BUFFER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2PRESCALER AND SYNTHESIZER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2LOOP FILTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2DIGITAL CONTROL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2VOLTAGE REGULATORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3TEST AND ALIGNMENT PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4OUTLINE DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6PRODUCTION CHANGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7IC DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8ASSEMBLY DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10SCHEMATIC DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11e

The divided reference signal and the divided multipliersignal are compared in the PLL phase detector. When thereference and multiplier signals are identical the PLL phasedetector generates a constant DC output voltage. This voltageis buffered by U8 and filtered by the loop filter circuit. It is thenapplied to Q1 setting the VCO on frequency.If the compared frequencies (phases) differ, an error voltageis generated which adjusts the VCO frequency. During thisout-of-lock condition, the PLL also sends a Lock Detect (LD)signal to the controller and lights the FAULT LED on the frontpanel of the module.Copyright© June 1992 Ericsson GE Mobile Communications Inc.Figure 1 - Receiver Synthesizer Block DiagramTable 1 - General SpecificationsITEM SPECIFICATIONFREQUENCY TUNINGMechanicalElectricalFull SpecificationsDegraded SpecificationsChannel SpacingINJECTION FREQ FREQ. BAND424.4 MHz-451.4 MHz (G3) 450-470 MHz, 403-425 MHz446.4 MHz-472.6 MHz (G7) 425-450 MHz, 470-495 MHz401.4 MHz-421.4 MHz (G8) 380-400 MHz470.6 MHz-490.6 MHz (G10) 492-512 MHz391.4 MHz-421.4 MHz (G12) 370-390 MHz2 MHz3 MHz6.25 kHzFREQUENCY STABILITYLO POWER OUTPUTLO NOMINAL IMPEDANCEPHASE NOISE@ 25 kHz OffsetHUM AND NOISECompanion Receiver±1.5 ppm2.0 dBm ±2 dBm50 ohms>-137 dBc/Hz-55 dBHARMONICS @ LO PORTSWITCHING SPEEDCURRENT DRAIN+13.8V+12V<-30 dBc<50 ms<200 mA<50 mAREFERENCE OSCILLATORFrequency OutputPower OutputImpedance12.8 MHz ±1.5 dBm1 dBm ±2 dBm50 ohmsEXT. REFERENCE OSCILLATORFrequencyPowerImpedance5.00 MHz to 17.925 MHz (must be integerdivisible by the channel spacing)+10 dBm ±3 dBm into 50 ohms50 ohmsThis manual is published by Ericsson Inc., without any warranty. Improvements and changes to this manual necessitated by typographical errors,inaccuracies of current information, or improvements to programs and/or equipment, may be made by Ericsson Inc., at any time and withoutnotice. Such changes will be incorporated into new editions of this manual. No part of this manual may be reproduced or transmitted in any formor by any means, electronic or mechanical, including photocopying and recording, for any purpose, without the express written permission ofEricsson Inc.LBI-38672J1

CIRCUIT ANALYSISThe Receiver Synthesizer Module consists of the follow-ing circuits:•Voltage Controlled Oscillator•Multiplier (Frequency Doubler)•Buffer Amplifiers•Reference Oscillator and Buffer•Prescaler and Synthesizer•Loop Filter•Digital Control•Voltage RegulatorsVOLTAGE CONTROLLED OSCILLATORThe free running Voltage Controlled Oscillator (VCO) iscomposed of a grounded-gate JFET (Q1) and associatedcircuitry. Inductor L10 and associated capacitors form theresonant tank circuit. The circuit’s use of high-Q componentsminimizes phase noise.Frequency tuning of the VCO is done by changing theDC output voltage level from the loop filter U14. The LoopFilter Out signal from U14 is routed through L4 and R3 andapplied to the two varicap diodes D4 and D5. The voltagelevel applied determines the diodes’ capacitance and sets theresonant frequency of the oscillator. If the VCO drifts or thefrequency is changed, the DC voltage level changes causingthe VCO’s resonant frequency to change. The output of theoscillator is then applied to a buffer amplifier. Course adjust-ment of frequency is done by adjusting trimmer capacitorC52 while applying a calibration voltage to the V_TUNE lineconnected to U14.4 pin 11.FREQUENCY DOUBLERTransistors Q14 and Q15 form a buffer stage to drivetransistor multiplier Q16. They isolate VCO Q1 from loadingeffects which would degrade oscillator loaded Q and hencenoise performance. Transistor multiplier Q16 is tuned to passthe second harmonic of the VCO output and hence serves asa frequency doubler. Tank elements L1, C97-C99 and L12form a resonant circuit and matching network to drive theresistive splitter (R13, R17, R18, R96, R97, R99, R100).RF AMPLIFIERSThe RF chain begins with a resistive splitter (R13, R17,R18, R96, R97, R99 and R100). The output of the splitter atR99 is attenuated by 7.5 dB and provides impedance match-ing to Helical Filter FL1 which is tuned to pass the LOFrequency while rejecting harmonics by about 40 dB. Theoutput of FL1 is fed thru resistive pad R12, R14 and R15 toMMIC Amp U2 which operates in compression. OutputAmp U2 is followed by a bandpass filter (L13-L15, C86, C87and C101) and resistive attenuator (R30, R101 and R102).The final output at the front panel BNC connector J2 isnominally 1.5 dBm and drives the Receiver Front End LOinput.The other output at the resistive splitter at R100 is attenu-ated by 20 dB and drives buffer amp U3 into compression.U3 drives the synthesizer prescaler, providing a feedbacksignal for the synthesizer phase locked loop.REFERENCE OSCILLATOR AND BUFFERThe reference oscillator section provides a reference sig-nal to the PLL section. The circuit design allows using eitheran external or internal oscillator.When using an external oscillator, the internal oscillatoris disabled by placing a logic low on the INT OSC line fromthe T/R Shelf Interface Board. A high precision externaloscillator may then be connected to the module through theexternal reference oscillator connector J4, EXT REF IN. J4has a 50 ohm input impedance and is coupled to the base ofQ12. Buffer Q12 conditions the signal and applies it to thesynthesizer U6 via coupling capacitor C10.The internal reference oscillator, Y1, provides a 12.8MHz signal with a stability of ±1.0 ppm. It is enabled byapplying a logic high signal on the INT OSC line. This signalturns on Q2, allowing it to conduct and apply +5 volts to pin1 of the oscillator Y1. The 12.8 MHz output signal (Y1 pin2) is then sent to the synthesizer via coupling capacitor C9.The reference oscillator signal, either external or internal,is also routed to Q13 via coupling capacitor C54. The outputtaken from the emitter of Q13 is applied through C11 to theinput of Buffer Amplifier U4. The buffered signal is coupledthrough C12 to a low pass filter network (C32,C33,C34, andL7) and a resistive pad (R27, R28, and R31) for isolation.The output from the resistive pad is then connected to J3,REF OUT, making the reference oscillator signal availablefor external use.PRESCALER AND SYNTHESIZER ICThe integrated circuit U6 is the heart of the synthesizer. Itcontains the necessary frequency dividers and control circuitryto synthesize output frequencies by the technique of dualmodulus prescaling. U6 also contains an analog sample andhold phase detector and a lock detector circuit.Within U6 are three programmable dividers which areserially loaded using the CLOCK, DATA, and ENABLE inputs(pins 11, 12, and 13 respectively). A serial data stream (DATA)on pin 12 is shifted into the internal shift registers by low tohigh transitions on the clock input (CLOCK) at pin 11. A logichigh (ENABLE) on pin 13 then transfers the program informa-tion from the shift registers to the divider latches. The serialdata determines the VCO frequency by setting the internal R,A, and N dividers.The 12.8 MHz reference oscillator signal OSCIN is inter-nally routed to the "R" divider. The "R" divider divides downthe 12.8 MHz reference signal to a lower frequency, Fr, asdirected by the input data and applies the signal to the internalanalog phase and lock detectors.The "A" and "N" dividers process the loop feedback signalfrom the multiplier (by way of the dual modulus prescaler U5).The output of the "N" divider, Fv, is a divided down version ofthe multiplier output frequency. This signal is also applied tothe internal phase detector. The ramp and hold constants aredetermined by C26, R37, C31, and R36.The analog phase detector output voltage (PD OUT) isproportional to the phase difference between Fv and Fr. Thisoutput serves as the loop error signal. When operating on thecorrect frequency, the inputs to the phase detector are identicaland the output voltage of the analog phase detector is constant.If the compared frequencies (phases) differ, the analog phasedetector increases or decreases the DC output voltage (PDOUT). This error signal voltage tunes the VCO to whateverfrequency is required to keep Fv and Fr locked (in phase).The lock detector furnishes the Fault circuit in U13 withthe lock detect (LD) signal. When Fv and Fr are in phase, thelock detector output sends a logic high on the LD line to thefault circuit U13. If the VCO is not locked onto the correctfrequency, the resulting out-of-phase condition causes the out-put from the lock detector to be a logic low.LOOP FILTERThe error signal, ANOUT, is applied to the loop filter atU8.2 pin 5 and U8.1 pin 3. U8.2 acts as a buffer amplifier withgain. The output signal from the amplifier is applied to a loopfilter consisting of R42, R43, R44, C35 and C36 via thebilateral switch U14. The filter removes noise and samplingfrequencies from the error voltage. The switch, U14, selects theproper filter configuration for operation in the narrow band,wide band or tuning mode. The control signals (OPEN_LOOP,ENABLE_NOT, and TUNE_CTRL) for U14 are derived fromthe digital control circuits U10, U12, and U13. U8.1 providesa buffered output for testing at the DIN connector on the rearof the module.DIGITAL CONTROLLogic control circuits (other than those inside the synthe-sizer IC - U6) consist of the following:•Digital Control Circuit (U10, U12, & U13)•Level Shifters•Fault CircuitThe Digital Control Circuits U10, U12, & U13 serve as aninterface between the controller and the synthesizer IC.As an address decoder, U10 enables the input gates whenthe A0, A1, and A2 input lines (pins 4, 3, and 2) receive thecorrect address code from the controller. For the Receiversynthesizer the enable address is 010 on A0, A1, and A2respectively. After receiving the proper logic code, the inputgate U12 is enabled. This allows the ENABLE, CLOCK, andserial DATA information to pass on to the synthesizer via thelevel shifters.The Level Shifters Q3, Q4, and Q5 convert the five voltlogic level to the eight volt logic level required by the synthe-sizer.The Fault circuit, U13, monitors the lock detect signal fromthe PLL synthesizer. Under normal (locked) condition, the PLLsends a logic high signal to U13. U13 processes the signal andprovides a logic high output which saturates Q6. Saturating Q6turns off the FAULT LED (CR1). U13 also sends a logic highsignal, FLAG 2, (U13.3 pin 8) to the controller indicating theVCO’s frequency is correct.LBI-38672J2

When the VCO is not on the correct frequency, the synthe-sizer sends a logic low signal to U13. This causes U13 to cutoffQ6 which turns on the FAULT LED (CR1). U13 also sends alogic low signal to the controller, on the FLAG 2 line, indicat-ing the VCO’s frequency is incorrect.VOLTAGE REGULATORSVoltage regulators U15 and U16 reduce the +13.8 VF lineto +5 Vdc and +8 Vdc respectively. The output from U15(+5V_SYN) is used by both the synthesizer and logic circuitrywhile the 8 Vdc output from U16 is used for the op-amps, levelshifters, and the discrete +8V OSC regulator circuit.The discrete +8V OSC regulator circuit is a linear regulatorconsisting of U9A, Q7, Q8, and associated circuitry. The erroramplifier U9A controls Q7 and pass element Q8. The +8V OSCis used as the power source for the VCO circuit, where addi-tional filtering is provided to keep noise to a minimumMAINTENANCERECOMMENDED TEST EQUIPMENTThe following test equipment is required to test the Synthe-sizer Module:1. Modulation Analyzer; HP 8901A, or equivalent2. Power Supply; 12.0 Vdc @ 500 mA3. Frequency Counter; 10 MHz - 250 MHz4. Power Meter; -20 dBm to +10 dBm5. Spectrum Analyzer, 0 - 1 GHzTEST AND ALIGNMENTINITIALIZATIONApply +12 Vdc to the test fixture.Current ConsumptionMeasure the current through pins 15A, 15B, 15C, 16A,16B, AND 16C.Verify the current is less than 250 mA. Total currentis the +13.8 VF current and +12 Vdc current com-bined.Reference OscillatorAdjust Y1 for an output frequency of 12.8 MHz ±2 Hz.Measure the output power of the reference oscillator output(J3).Verify the output power is 1 dBm ±2 dBm.Oscillator AlignmentGround the ENABLE TEST line (pin 22A). Apply +4Vdc to the V_TUNE line (pin 26A). Measure the frequencyof the free running multiplied oscillator at the LO OUT port(J2).Adjust the trimmer capacitor C52 for 445 MHz(G3), 470 MHz (G7), 420 MHz (G8), 490 MHz(G10), 420 MHz (G12) or desired injection fre-quency ±100 kHz.Synthesizer LoadingUnground the ENABLE TEST line (pin 22A). Load thesynthesizer IC for 445 MHz (G3) or 470 MHz (G7) or 420MHz (G8), 490 MHz (G10), 420 MHz (G12) or desiredinjection frequency.Verify the lock indicator (CR1) is off or the FLAG2 line is high.Hum and NoiseInitialize the HP 8901A for 300 Hz - 3 kHz, 750 µsecde-emphasis, average FM deviation, and 0.44 dB referencefor the deviation.Verify the hum and noise (J2) is less than -55 dB.Output Power and Harmonic ContentAdjust both slugs on FL1 for maximum output levelmeasured at J2.Verify the output power (J2) at the fundamental fre-quency is:2 dBm ±2 dBVerify the harmonic content is less than -30 dBc.The following service information applies when aligning,testing, or troubleshooting the RX Synthesizer:•Logic Levels:Logic 1 = high = 4.5 to 5.5 VdcLogic 0 = Low = 0 to 0.5 Vdc•Receiver Synthesizer Address = A0 A1 A2 = 010•Synthesizer data input stream is as follows:14-bit "R" divider most significant bit (MSB) = R13through "R" divider least significant (LSB) = R010-bit "N" divider MSB = N9 through "N" dividerLSB = N07-bit "A" divider MSB = A6 through "A" dividerLSB = A0Single high Control bit (last bit)Latched When Control Bit = 1DATA ENTRY FORMATLatched WhenControl Bit = 1LastBit A0LSB - - - A6MSB N0MSB - - N0MSB R0LSB - - - R13MSBControl Bit•Synthesizer lock is indicted by the extinguishing of thefront panel LED indicator and a logic high on the faultFLAG 2 line (J1 pin 12C).•Always verify synthesizer lock after each new dataloading.SERVICE NOTESData in→Shift→RegisterOutLBI-38672J3

TROUBLESHOOTING CHARTSYMPTOM AREAS TO CHECK INDICATIONSI. Loop Fails To Lock 1. Check for:+8 Vdc at U16-3,+5 Vdc at U15-3+8 Vdc at Q8-C.2. Check for 12.8 MHzreference at U6-2 and U6-3.Typical Levels:500 mVpp @U6-22.5 Vpp @U6-3.3. Check for LO output @J2.FLO ±5 MHz, 0 dBm nominal4. Check Prescaler output @U5-4.Typically: 2-4 MHz square wave@1.25 Vpp.5. Check for CLOCK, DATA,and ENABLE signals at U6pins 11, 12 and 13 respectively.(0, 8V logic levels)6. Check Ramp Signal @U6-15.It should be 6.25 kHz nominal.Bad Regulation circuitry.Troubleshooting usingstandard procedures.Reference Osc. Module defective or supplynot present or low. Proceed to referenceoscillator section II.LO tuning incorrect, or buffer amplifier bad.Proceed to LO tuning and power section III.If LO power is good, check for 3.2 Vdc@U2-3. Replace U2, then U5 if necessary.Bad digital control circuitry.Troubleshoot using standard procedures.Ensure all programming signals are presentat J1. (CLOCK, DATA, ENABLE, A0, A1and A2).If reference oscillator and programmingsignals are present for proper programminginformation. Last resort - replaceSynthesizer IC U6.II. Reference OSC. not present orlow power. 1. Check for 4.3 Vdc supply atjunction of R5 and C41.2. Check 12.8 MHz signal @Q13-E.Should be approx. 350 mVpp.Bad supply switch Q2 or wrong Control Signal Internal Osc.Troubleshooting using standard procedures.Replace Y1 as last resort.Bad buffer amplifier Q13.Troubleshoot using standard procedures.III. LO power low ortuned out of band. 1. Check tuning with 6 Vdc appliedusing test procedure. FLO ±5 MHz.2. Check DC bias at Buffer Amplifiers U1, U2, & U3 pin 3 Typ. 3.2 Vdc.LO tuning incorrect. Retune followingtest procedure.Bad Buffer Amplifier. Replace bad part.IV. LO signal not present.(i.e. Q1 does not oscillate) 1. Check DC bias at Q1 drain.(Typ. +8Vdc).2. Check DC bias at Q1 source.(Typ. +0.9 Vdc).Replace Q1.LBI-38672J4

OUTLINE DIAGRAMUHF RECEIVER SYNTHESIZER BOARD19D902664G3 ,G7, G8, G10, G12COMPONENT SIDE(19D902664, Sh. 2, Rev. 4)(19D902665, Layer 1, Rev. 1)LBI-38672J5

PARTS LIST & PRODUCTION CHANGESPRODUCTION CHANGESChanges in the equipment to improve performance or to simplify circuits areidentified by a "Revision Letter" which is stamped after the model number ofthe unit. The revision stamped on the unit includes all previous revisions. Referto the Parts List for the descriptions of parts affected by these revisions.REV. A - UHF RECEIVER SYNTHESIZER BOARD 19D902664G3The UHF Receiver Synthesizer module was modified tomeet ETSI requirements.Items 3 and 7 were changed and item 23 was added.Item 3 was: 19D902509P3.Item 7 was: 19A702381P513.C16 was 6.8 pF (19A702236P21).C2 was deleted (19A702236P10).REV. A - UHF RECEIVER SYNTHESIZER BOARD 19D902664G7REV. B - UHF RECEIVER SYNTHESIZER BOARD 19D902664G3To improve operation.C3 was 22 pF (19A702236P34).C5 was 10 pF (19A702236P25).C6 was 18 pF (19A702236P32).C16 was 8.2 pF (19A702236P23).R4 was 47 ohms (19B800607P470).REV. B - UHF RECEIVER SYNTHESIZER BOARD 19D902664G7REV. C - UHF RECEIVER SYNTHESIZER BOARD 19D902664G3To support 12.5kHz operation, changed Y1.Was 1.5PPM crystal (19B801351P12).REV. C - UHF RECEIVER SYNTHESIZER BOARD 19D902664G7To reduce spurious radiation to meet ETSI specs.L12 and R18 interchanged. L2 was 1uH (19A700024P13).REV. D - UHF RECEIVER SYNTHESIZER BOARD 19D902664G3 & G7To prevent regulator from drop out at low voltages.R10 was 10 ohms (19B800607P100).REV. E - UHF RECEIVER SYNTHESIZER BOARD 19D902664G3To correct timing range added C2 (and changed C16).C16 was 8.2 pF (19A702236P23).SYMBOL PART NO. DESCRIPTIONR17 19B800607P120 Metal film: 12 ohms + or -5%, 1/8 w.R18 19B800607P180 Metal film: 18 ohms + or -5%, 1/8 w.R19 19B800607P100 Metal film: 10 ohms + or -5%, 1/8 w.R20 19B800607P103 Metal film: 10K ohms + or -5%, 1/8 w.R21 19B800607P472 Metal film: 4.7K ohms + or -5%, 1/8 w.R22 19B800607P271 Metal film: 270 ohms + or -5%, 1/8 w. R23 19B800607P103 Metal film: 10K ohms + or -5%, 1/8 w.R24 19B800607P562 Metal film: 5.6K ohms + or -5%, 1/8 w.R27 19B800607P181 Metal film: 180 ohms + or -5%, 1/8 w.R28 19B800607P181 Metal film: 180 ohms + or -5%, 1/8 w.R29 19B800607P103 Metal film: 10K ohms + or -5%, 1/8 w.R30 19B800607P560 Metal film: 56 ohms + or -5%, 1/8 w.(Used in G3, G7, G8, G12).R30 19B800607P680 Metal film: 68 ohms + or -5%, 1/8 w. (Used in G10).R31 19B800607P270 Metal film: 27 ohms + or -5%, 1/8 w.R32 19B800607P472 Metal film: 4.7K ohms + or -5%, 1/8 w.R33 19B800607P472 Metal film: 4.7K ohms + or -5%, 1/8 w.R34 19B800607P103 Metal film: 10K ohms + or -5%, 1/8 w.R35 19B800607P103 Metal film: 10K ohms + or -5%, 1/8 w.R36 19B800607P393 Metal film: 39K ohms + or -5%, 1/8 w.R37 19B800607P104 Metal film: 100K ohms + or -5%, 1/8 w.R38 19B800607P682 Metal film: 6.8K ohms + or -5%, 1/8 w.R39 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.R40 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.R41 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.R42 19B800607P823 Metal film: 82K ohms + or -5%, 1/8 w.R43 19B800607P333 Metal film: 33K ohms + or -5%, 1/8 w.R44 19B800607P274 Metal film: 270K ohms + or -5%, 1/8 w.R45 19B800607P472 Metal film: 4.7K ohms + or -5%, 1/8 w.R46 19B800607P181 Metal film: 180 ohms + or -5%, 1/8 w.R47 19B800607P271 Metal film: 270 ohms + or -5%, 1/8 w.R48 19B800607P181 Metal film: 180 ohms + or -5%, 1/8 w.R49 19B800607P103 Metal film: 10K ohms + or -5%, 1/8 w.R50 19B800607P103 Metal film: 10K ohms + or -5%, 1/8 w.R51 19B800607P103 Metal film: 10K ohms + or -5%, 1/8 w.R52 19B800607P473 Metal film: 47K ohms + or -5%, 1/8 w.R53 19B800607P473 Metal film: 47K ohms + or -5%, 1/8 w.R54 19B800607P473 Metal film: 47K ohms + or -5%, 1/8 w.R55 19B800607P222 Metal film: 2.2K ohms + or -5%, 1/8 w.R57 19B800607P473 Metal film: 47K ohms + or -5%, 1/8 w.R58 19B800607P681 Metal film: 680 ohms + or -5%, 1/8 w.R59 19B800607P222 Metal film: 2.2K ohms + or -5%, 1/8 w.R60 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.R61 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.R62 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.R63 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.R64 19B800607P510 Metal film: 51 ohms + or -5%, 1/8 w.R65 19B800607P103 Metal film: 10K ohms + or -5%, 1/8 w.R66 19B800607P103 Metal film: 10K ohms + or -5%, 1/8 w.R67 19B800607P473 Metal film: 47K ohms + or -5%, 1/8 w.R68 19B800607P473 Metal film: 47K ohms + or -5%, 1/8 w.R69 19B800607P333 Metal film: 33K ohms + or -5%, 1/8 w.R70 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.SYMBOL PART NO. DESCRIPTIONR71 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.R72 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.R73 19B800607P103 Metal film: 10K ohms + or -5%, 1/8 w.R74 19B800607P103 Metal film: 10K ohms + or -5%, 1/8 w.R75 19B800607P103 Metal film: 10K ohms + or -5%, 1/8 w.R76 19B800607P103 Metal film: 10K ohms + or -5%, 1/8 w.R77 19B800607P101 Metal film: 100 ohms + or -5%, 1/8 w.R78 19B800607P101 Metal film: 100 ohms + or -5%, 1/8 w.R79 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.R80 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.R81 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.R82 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.R83 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.R84 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.R85 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.R86 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.R87 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.R88 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.R89 19B800607P103 Metal film: 10K ohms + or -5%, 1/8 w.R90 19B800607P222 Metal film: 2.2K ohms + or -5%, 1/8 w.R91 19B800607P101 Metal film: 100 ohms + or -5%, 1/8 w.R92 19B800607P101 Metal film: 100 ohms + or -5%, 1/8 w.thruR94R95 19B800607P101 Metal film: 100 ohms + or -5%, 1/8 w.R96 19B800607P221 Metal film: 220 ohms + or -5%, 1/8 w.R97 19B800607P220 Metal film: 22 ohms + or -5%, 1/8 w.R98 19B800607P180 Metal film: 18 ohms + or -5%, 1/8 w.R99 19B800607P120 Metal film: 12 ohms + or -5%, 1/8 w.R100 19B800607P330 Metal film: 33 ohms + or -5%, 1/8 w.R101andR10219B800607P121 Metal film: 120 ohms + or -5%, 1/8 w.(Used in G3, G7, G8, G12).R101andR10219B800607P101 Metal film: 100 ohms + or -5%, 1/8 w. (Used in G10).R103 19B800607P390 Metal film: 39 ohms + or -5%, 1/8 w.- - - - - - - - INTEGRATED CIRCUITS - - - - - - -U2 19A705927P1 Silicon, bipolar: sim to Avantek MSA-0611.U3 19A705927P1 Silicon, bipolar: sim to Avantek MSA-0611.U4 19A705927P1 Silicon, bipolar: sim to Avantek MSA-0611.U5 19A149944P201 Dual Modulus Prescaler: sim to MotorolaMC12022A.U6 19B800902P5 Synthesizer, custom: CMOS, serial input.U8 19A702293P3 Linear: Dual Op Amp; sim to LM358D.U9 19A702293P3 Linear: Dual Op Amp; sim to LM358D.U10 19A703471P320 Digital: 3-Line To 8-Line Decoder; sim to74HC138.U12 19A703483P302 Digital: Quad 2-Input NAND Gate; sim to 74HC00.andU13U14 19A702705P4 Digital: Quad Analog Switch/Multiplexer; sim to4066BM.U15 19A704971P8 Voltage Regulator, Positive: sim to MotorolaMC78M05CDT.U16 19A704971P10 Voltage Regulator, 8V: sim to MC78M08CDTLBI-38672J7

IC DATAU619B80090P5SynthesizerU2 thru U419A705927P1Silicon Bipolar ICU8 & U919A702293P3Dual Operational AmplifierU519A149944P201Modulus PrescalerU1419A702705P4Quad Analog SwitchU1019A703471P120Decoder/DemuxU12 & U1319A703483P302Logic Gate/InverterLBI-38672J8

IC DATAU1619A704971P10+8V RegulatorU1519A704971P8+5V RegulatorY119B801351P12Crystal OscillatorLBI-38672J9

ASSEMBLY DIAGRAMRECEIVER SYNTHESIZER MODULE19D902781G3, G7, G8, G10, G12(19D902781, Sh. 2, Rev. 5)LBI-38672J10

SCHEMATIC DIAGRAMRECEIVER SYNTHESIZER MODULE19D902664G3, G7, G8, G10, G12(19D904091, Sh. 1, Rev. 9A)LBI-38672J11

SCHEMATIC DIAGRAMRECEIVER SYNTHESIZER MODULE19D902664G3 , G7, G8, G10, G12(19D904091, Sh. 2, Rev. 9A)LBI-38672J12

SCHEMATIC DIAGRAMRECEIVER SYNTHESIZER MODULE19D902664G3, G7, G8, G10, G12(19D904091, Sh. 3, Rev. 9A)LBI-38672J13

LBI-38673FTABLE OF CONTENTSPageDESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Front CoverSPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1CIRCUIT ANALYSISPRESELECTOR FILTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1PREAMPLIFIER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1IMAGE REJECTION FILTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1INJECTION AMPLIFIER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1INJECTION FILTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1DOUBLE BALANCE MIXER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1FAULT DETECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1MAINTENANCETEST PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2ALIGNMENT PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2TROUBLESHOOTING PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1TABLE 2 - RETUNING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3PRODUCTION CHANGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4OUTLINE DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4ASSEMBLY DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6SCHEMATIC DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8MAINTENANCE MANUAL FORRECEIVER FRONT END MODULE19D902782G3, G4, & G7DESCRIPTIONThe Receiver Front End (RXFE) Module amplifiesand converts the Rf signal to the first IF signal of 21.4MHz. This is a down conversion process using low side(G3, G4) or high side (G7) injection. The RXFE moduleis powered by a regulated 12 volts. The RXFE printedwiring board contains the following functional circuits:•Preselector Filter•Preamplifier•Image Rejection Filter•Injection Amplifier•Injection Filter•Double Balanced Mixer•Fault DetectorAll but the Fault Detector circuit in the RXFE mod-ule have 50 ohm impedance terminations.EEricsson Inc.Private Radio SystemsMountain View RoadLynchburg, Virginia 245021-800-592-7711 (Outside USA, 804-592-7711) Printed in U.S.A.

CIRCUIT ANALYSISPRESELECTOR FILTERThe received RF signal (J2) is routed through the Prese-lector Filter. This filter provides front end selectivity andattenuates the potential spurious signals of first conversion.Typically, the filter has an insertion loss is 3 dB and an opera-tional bandwidth of 2 MHz. The filter is primarily a five-polehelical bandpass filter (L1 thru L5) and is tunable in the bandsplit MHz range.PREAMPLIFIERThe output from the Preselector is coupled through animpedance matching network consisting of L6, C2, and DCblocking capacitor C1 to the base of Preamplifier Q1. Q1 is abroadband common emitter amplifier. The Preamplifier stageis supplied by the regulated +12 Vdc line (VCC1) and drawsabout 70 mA through R4. It has a low noise figure and highThird Order Intercept point. Transistor Q2 provides Q1 with aconstant voltage and current source. The bias on Q1 is moni-tored by the Fault Detector circuit via R17. Capacitors C20 andC21 prevent the RF component from entering the fault circuit.The output signal is coupled to the Image Rejection Filter viaan impedance matching network consisting of C4, L8, andresistors R5 and R6.IMAGE REJECTION FILTERFollowing the Preamplifier is the Image Rejection Filter.The Image Rejection Filter is a fixed tuned helical bandpassfilter and can meet the desired image rejection of the frequencyband.INJECTION AMPLIFIERThe local oscillator input (J3) from the Receiver Synthe-sizer is coupled through an impedance matching network (C5and L9) to the base of the Injection Amplifier Q3. Q3 and Q8are common emitter amplifiers. The output from Q3 is coupledthrough an impedance matching network (C6, C7, and L11) tothe base of Q8. The Injection Amplifier, consisting of Q3, Q8,and associated circuitry, is capable of amplifying the injectionsignal from 0 dBm to +25 dBm in the 428 to 449 MHz rangeor to +18 dBm in the 446-472 MHz range. The amplifier ispowered by the regulated +12 Vdc line (VCC1). TransistorsQ4 and Q7 provide Q3 and Q8 with a constant voltage andcurrent source. The bias on Q3 and Q8 is monitored by theFault Detector circuit via R21 and R31, respectively. Capaci-tors C22, C23 and C26 prevent the RF component fromentering the fault circuit. The output signal is coupled to theInjection Filter via an impedance matching network consist-ing of C8, L13, and resistors R15 and R16.INJECTION FILTERFollowing the Injection Amplifier is the Injection Filterconsisting of C9 through C19, L14 through L20, and R30.Configured as a bandpass filter, the Injection Filter has abandwidth of 428 to 450 MHz (G3, G4) or 446 to 472 MHz(G7) and is used to attenuate the harmonics of the InjectionAmplifier. The filter also has an insertion loss of about 2 dB.DOUBLE BALANCE MIXERThe Double Balance Mixer (DBM) is a broadbandmixer. It converts an RF signal to the 21.4 MHz first conver-sion IF frequency. The mixer uses low side (G3, G4) or highside (G7) injection driven by a local oscillator signal of +20(G3, G4) or +15 (G7) dBm. The mixer conversion loss istypically about 6.5 dB. The IF output signal is then routed tothe output connector (J4).FAULT DETECTORThe Fault Detector circuit monitors the operation ofpreamplifier and injection amplifier devices. Operationalamplifiers U1.1 and U1.2 compare the bias on the Preampli-fier Q1 to preset levels, while U1.3 and U1.4 compare thebias levels on Injection Amplifiers Q3 and Q8.When the bias for Q1, Q3, and Q8 is within the presetwindow limits, the output from the comparators is a highlevel. This causes Q5 to conduct, turning off Q6 and the faultindicator, CR2. A high level signal is also sent to the Con-troller on the FLAG 0 line.Copyright© July 1992, Ericsson GE Mobile Communications, Inc.Table 1 - General SpecificationsITEM SPECIFICATIONFREQUENCY RANGE 450.0 MHz - 470.0 MHz (G3, G4)425.0 MHz - 470.0 MHz (G7)IF FREQUENCY 21.4 MHz3 dB BANDWIDTH >3 MHzIMPEDANCE 50 ohms at RF, LO, and IF PortsCONVERSION LOSS -2 dB ±1 dBNOISE FIGURE (NF) <7.5 dBTHIRD ORDER INTERCEPT POINT >+20 dBm (G3, G4)>+15 dBm (G7)IMAGE REJECTION >100dBINJECTION POWER +2 dBm ±2 dBTEMPERATURE RANGE -30°C TO +60°CSUPPLY VOLTAGE 12.0 VdcSUPPLY CURRENT 290 mA ±20 mA typical230 mA ±20 mA typical (G3) Figure 1 - Block DiagramLBI-38673F1

If the biasing for the amplifiers is not within the properoperating range, the fault detector circuit will pull the FLAG0 line low. This turns off Q5 causing Q6 to conduct. Q6 nowprovides a ground path for CR2, turning on the fault indica-tor.MAINTENANCETEST PROCEDUREThe RXFE module has to be tested for Noise Figure,Gain, Third Order Intercept Point, Isolation etc.. With propercurrent drawing of devices, Bandwidth and Conversion Gainthe RXFE module will meet its specifications. The followingare test procedures will verify proper Conversion Gain andcurrent drain:1. Supply 12 Vdc to pin 15A, B, C. (1C is ground.)2. Inject the desired RF signal into RF IN at a level of-10 dBm.3. Inject the desired local oscillator signal into LO INat a level of 0 dBm [LO frequency = RF frequency -21.4 MHz (G3, G4) + 21.4 MHz (G7)].4. Measure the IF OUT power at 21.4 MHz, the ratio ofRF IN to IF OUT is -2 dB ±1 dB.5. Measure the current drawn by the RXFE module.Typical current drain is 290 mA.ALIGNMENT PROCEDUREAlignment for the Receiver Front End module consistsof tuning the five-pole Preselector Filter only. Normally, theRXFE should only need the fine-tuning procedures. For amajor receiver frequency change, the RXFE needs to beadjusted using the major-retuning procedures.For Fine-Tuning1. Supply 12 Vdc to pin 15A, B, C. (1C is ground.)2. Inject the desired RF signal into RF IN (J2) at a levelof -10 dBm.3. Inject the desired local oscillator signal into LO IN(J3) at a level of 0 dBm [LO frequency = RF fre-quency - 21.4 MHz (G3, G4) + 21.4 MHz (G7)].4. Detect IF signal at 21.4 MHz. Slightly adjust L1 toL5 to get maximum power (don’t adjust more thanten degrees). If an RF Voltmeter is used, connect aLow Pass Filter (LPF)to the IF OUT (J4) to attenuatehigh frequency components. The corner of the LPFshould be set for 40 MHz.5. Repeat Test Procedure steps to verify conversiongain and current drain.For Major RetuningThe best way to do a major retuning of the RXFE is withswept frequency tuning. The swept frequency tuning can bedone using a Spectrum Analyzer and Tracking Generator.With proper Injection power and current drain, the frequencyresponse of the Preselector Filter can be seen by viewing theRF to IF port feedthrough on the spectrum analyzer. Thisfeedthrough is typically 35 dB down from the input level atthe RF port. Use the following procedure for swept fre-quency tuning:1. Supply 12 Vdc to pin 15A, B, C. (1C is ground.)2. Inject the Tracking generator output at 0 dBm intothe RF IN connector, (J2).3. Inject local oscillator power at 0 dBm into the LO INconnector, (J3) [LO frequency = RF frequency - 21.4MHz (G3, G4) + 21.4 MHz (G7)].4. Preset the height of slugs with respect to the top offive-pole cavity as follows (Table 2):Table 25. Center the spectrum analyzer at the desired frequencyand set the reference at about -30 dBm. Adjust L1 toL5 for best possible response.HEIGHT (in inches)Frequency(MHz)L1 L2L3L4L5450 15/64 16/64 17/64 17/64 16/64454 16/64 17/64 17/64 18/64 15/64458 16/64 19/64 19/64 19/64 17/64462 18/64 19/64 20/64 20/64 18/64466 21/64 22/64 23/64 21/64 20/64470 22/64 24/64 24/64 23/64 22/64SYMPTOM AREAS TO CHECK READING (TYP.)LOW CONVERSION GAIN Check Vcc 12 VPreselector Loss 3.5 dBPreamplifier Gain 11 dBImage Rej. Filter Loss 2 dB1st Mixer Conversion Loss 6.5 dB1 L.O. Level (@ mixer L.O. +22 ±2 dBm (G3, G4)port) +14 ±2 dBm (G7)LED INDICATOR ON Check Vc of Q1 10 VCheck Vc of Q3 and Q8 10 VIF FREQUENCY OFF Check L.O. FREQUENCY L.O. frequency = RF frequency - 21.4 MHz (G3,G4) + 21.4 MHz (G7)LOW L.O. POWER* Injection Amplifier Gain 23 ±2 dB (G3, G4)18 ±2 dB (G7)Injection Filter Loss 2 dB*NOTE: For troubleshooting the gain or loss, the RXFE needs to be under the normal operating condition:•12 Vdc supply.•Inject L.O. power at a level of 0 dBm into LO IN (J3), [LO freq. = RF freq. - 21.4 MHz (G3, G4)+ 21.4 MHz (G7).•Inject the desired RF signal at a level of -10 dBm into RF IN (J2).•Terminate the IF OUT (J4) with a good 50 ohm impedance.•Use a Spectrum Analyzer and 50 ohm probe (with good RF grounding) to probe at the input and output ofeach stage to check its gain or loss (see schematic diagram).TROUBLESHOOTING GUIDELBI-38673F2

OUTLINE DIAGRAMPARTS LIST & PRODUCTION CHANGESSYMBOL PART NUMBER DESCRIPTIONR23 19B800607P333 Metal film: 33K ohms ±5%, 1/8 w.andR24R25 19B800607P104 Metal film: 100K ohms ±5%, 1/8 w.(Used in G3).R26 19B800607P273 Metal film: 27K ohms ±5%, 1/8 w.(Used in G3).R27 19B800607P391 Metal film: 390 ohms ±5%, 1/8 w.(Used in G3).R28 19B800607P103 Metal film: 10K ohms ±5%, 1/8 w.R29 19B800607P682 Metal film: 6.8K ohms ±5%, 1/8 w.R30 19B800607P470 Metal film: 47 ohms ±5%, 1/8 w.R31 19B800607P103 Metal film: 10K ohm,±5%, 1/8w.R32 19B800607P560 Metal film: 56 ohms,±5%, 1/8w.R33 19B800607P510 Metal film: 51 ohms,±5%, 1/8w.(Used in G7).R34 19B801251P1 Metal film: 0 ohms.R35 19B800607P270 Metal film: 27 ohms,±5%, 1/8w. (Used in G7).— — — TRANSFORMERS — — T1 344A3063P1 Transformer.andT2— — INTEGRATED CIRCUITS — U1 19A704125P1 Linear: Quad Comparator; sim to LM339D.— — — MISCELLANEOUS — — 20 19B800701P2 Tuning screw.21 19A701800P1 Stop nut.22 19D902467P2 Casting.28 19D902534P2 Cover, RF. (Used in G4).29 19D904572P1 Cover, Gasket. (Used in G4).30 19B802690P1 Grommet. (Used in G4).U119A704125P1Quad Operational Amplifier(19D902490, Sh. 3, Rev. 5)RECEIVER FRONT END BOARD19D902490G3PRODUCTION CHANGES - CONT.REV. B - RECEIVER FRONT END BOARD 19D902490G7To improve receiver sensitivity L8 changed from 18nH (19A705470P4) to 33nH (19A705470P7);R5 changed from 10 ohms (19B800607P100) to 0 ohms (19B800607P1); R14 changed from 18 ohms (19B800607P180) to 27 ohms (19B800607P270); R6 (19B800607P391) and R36 (19B800607P391) were deleted.REV. D - RECEIVER FRONT END BOARD 19D902490G3Reduce excessive LO drive level. Changed R15 from10 ohms (19B800607P100) to 27 ohms (19B800607P270).Changed R16 from 390 ohms (19B800607P391) to180 ohms (19B800607P181).PRODUCTION CHANGESChanges in the equipment to improve or to simplify circuits areidentified by a "Revision Letter", which is stamped after the modelnumber of the unit. The revision stamped on the unit includes allprevious revisions. Refer to the Parts List for descriptions of partsaffected by these revisions.REV. A - RECEIVER FRONT END BOARD 19D902490G3Upgrade to ETSI specs. New PWB.REV. B - RECEIVER FRONT END BOARD 19D902490G3REV. A - RECEIVER FRONT END BOARD 19D902490G4To correct overheating problem.R14 was 10 ohms (19B800607P100).REV. C - RECEIVER FRONT END BOARD 19D902490G3To eliminate receiver spurious response at 100 kHzswitching power supply frequency.Added C29, C30, C31, C32 and L24.REV. B - RECEIVER FRONT END BOARD 19D902490G4REV. A - RECEIVER FRONT END BOARD 19D902490G7To eliminate receiver spurious response at 100 kHzswitching power supply frequency.Added C37, C38, C39, C40 and L24.LBI-38673F4

RECEIVER FRONT END BOARD19D902490G4 & G7OUTLINE DIAGRAM(19D902490, Sh. 4, Rev. 6A)LBI-38673F5

ASSEMBLY DIAGRAMRECEIVER FRONT END MODULE19D902782G3(19D902782 Sh.1 Rev. 6)LBI-38673F6

ASSEMBLY DIAGRAMRECEIVER FRONT END MODULE19D902782G4 & G7(19D902782 Sh.2 Rev. 6)LBI-38673F7

SCHEMATIC DIAGRAMRECEIVER FRONT END MODULE19D902782G4 & G7(19D904768 Sh.1 Rev. 6)LBI-38673F8

SCHEMATIC DIAGRAMRECEIVER FRONT END MODULE19D902782G3,G4 & G7(19D904768 Sh.2 Rev. 6)LBI-38673F9

SCHEMATIC DIAGRAMRECEIVER FRONT END MODULE19D902782G3(19D903498, Rev. 7)LBI-38673F10

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LBI-38674FTABLE OF CONTENTSDESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1CIRCUIT ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1POWER AMPLIFIER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Exciter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Small Signal Gain Stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Low Level Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Power Amplifier Finals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1POWER CONTROL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Signal Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2TROUBLESHOOTING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,3BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1POWER AMPLIFIER READINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3ASSEMBLY DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5,6,7PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8PRODUCTION CHANGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9,10IC DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11OUTLINE DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10,12SCHEMATIC DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11,12LOW PASS FILTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7,13MAINTENANCE MANUAL FOR450-470 MHz, 110 WATT POWER AMPLIFIER19D902797G3425-450 MHz, 90 WATT POWER AMPLIFIER19D902797G7403-425 MHz, 90 WATT POWER AMPLIFIER19D902797G6380-400 MHz, 75 WATT POWER AMPLIFIER19D902797G8470-494 MHz, 90 WATT POWER AMPLIFIER19D902797G9492-512 MHz, 90 WATT POWER AMPLIFIER19D902797G10410-430 MHz, 90 WATT POWER AMPLIFIER19D902797G11ericssonzEricsson Inc.Private Radio SystemsMountain View RoadLynchburg, Virginia 245021-800-528-7711 (Outside USA, 804-592-7711) Printed in U.S.A.

DESCRIPTIONThe UHF Power Amplifier Assembly is a wide band RFpower amplifier operating over the 380-400, 410-430, 403-425, 425-450, 450-470, 470-494, and 492-512 MHz rangewithout tuning. Its main function is to amplify the 10 mW FMsignal from the Transmitter Synthesizer to the rated RF outputat the antenna port. The output of the Power Amplifier Assem-bly is adjustable from rated power to 3dB lower at the PAoutput J104.The assembly consists of a printed wiring board (A1) andassociated components, including a power module and threeRF power transistors, mounted to the heat sink assembly. Theprinted wiring board (A1) contains both the power amplifiercircuitry and the power control circuitry.Unfiltered supply voltage, A+, for the power amplifiercircuits enters the assembly via feedthrough capacitor, C1.Power cable W4 routes the A+ from C1 to J103 on the PWB.Filtered A+ voltage for the power control circuit enters theassembly via control cable W13 which connects to the PWB atJ201.The Power Control circuitry sets the output power level byadjusting the PA Power Set level. It keeps the output powerconstant despite variations in input power, power amplifiergain, or temperature through the use of a feedback control loopin the PA assembly.CIRCUIT ANALYSISPOWER AMPLIFIERThe power amplifier section of the PA Board consists ofan Exciter, a Small Signal Gain Stage, a Low Level Amplifier,a Driver, and the Power Amplifier Finals. All these gain stageshave an input and output impedance of 50 ohms. Figure 1 is ablock diagram showing the signal flow within the Power Am-plifier Assembly.Exciter (U101)The Exciter stage uses a broadband silicon monolithicmicrowave integrated circuit (MMIC) amplifier. The signalfrom transmitter synthesizer, typically 10 dBm (10 mW), isinput to the Exciter through a 10 dB resistive pad (R1, R2, andR31). The Exciter amplifies the resulting 0 dBm (1 mW)signal to 12 dBm (16 mW).The MMIC requires a 5 volt supply source. The 8 voltregulator (U100) provides the 5 volts to the MMIC via adropping resistor R30.Small Signal Gain StageThe Small Signal Gain Stage consists of Q7 and itsassociated bias and matching circuitry. Collector voltage isfed through R39, R40, and L23. Resistor R33 sets the quies-cent bias of the part. The transistor input impedance ismatched to the 50 ohm output of the Exciter by C59, C61,C62, and C63. L24 provides the necessary output matching.The stage provides 14 dB of gain to amplify the signal fromthe Exciter to 26 dBm (400 mW).Low Level Amplifier (U102)The Low Level Amplifier (LLA) stage uses a 50 ohmthick film RF Power Module to amplify and control of theoutput power. Internally, the module is a three stage ampli-fier. The power control circuitry controls the gain of the firstand second stages by varying the collector voltage level ofQ203. The third stage gain remains constant with A+ provid-ing the DC supply voltage.The signal from the Small Signal Gain stage, typically26 dBm (400 mW), is input into the LLA. Under typicalPower Set conditions, the LLA amplifies the signal to atypical output level of 40.5 dBm (11.2 W).Driver (Q1)The driver is a 6 dB RF amplifier consisting of transistorQ1 and its associated circuitry. The signal from the LLA,typically 40.5 dBm (11.2 W), is amplified to 46.5 dBm (45.0W). The transistor input is matched to 50 ohms by C65, C66,C27, C67, and a piece of printed transmission line. The drivesignal is then split with a printed in-phase Wilkenson splitter,providing equal power to each of the final devices.Power Amplifier Finals (Q2, Q3)Each of the Power Amplifier Final devices is capable ofproducing 5 to 6 dB of gain. The output signal from theSplitter is impedance matched to each of the finals. Underoptimum conditions each final amplifies the input signal tobetween 50 and 70 watts output power (depending on bandsplit). The outputs are then impedance matched to the inputof the Combiner. The Combiner is a printed in-phase Wilkin-son type which combines (sums) the output power of thefinals. This produces an output power of approximately100W, (depending on band split) which is coupled to thedirectional coupler (part of A1 PWB) and on to the antennacircuits. In addition, the directional coupler samples bothforward and reverse power and sends this sample to thePower Control circuitry.Copyright © July 1992, Ericsson GE Mobile Communications Inc.Table 1 - General SpecificationsITEM SPECIFICATIONFREQUENCY 450 MHz - 470 MHz (G3)403 MHz - 425 MHz (G6)425 MHz - 450 MHz (G7)380 MHz - 400 MHz (G8)470 MHz - 494 MHz (G9)492 MHz - 512 MHz (G10)410 MHz - 430 MHz (G11)OUTPUT POWER (RF) 65 watts - 130 watts (G3)55 watts - 110 watts (G6, G7, G9, G10 & G11)45 watts - 90 watts (G8)INPUT POWER (RF) 10 mW min. into ≤ 2:1 VSWR.TEMPERATURE RANGE -30°C TO +60°C (Ambient air)SUPPLY VOLTAGE 13.4 VdcCURRENT 29 Amps max. (26 A typical @ rated power, 13.4V) (G3)29 Amps max. (21 A typical @rated power , 13.4V)(G6, G7, G9, G10 & G11)29 Amps max. (20 A typical @ rated power, 13.4V) (G8)DUTY CYCLE ContinuousSTABILITY Stable into 3:1 VSWR; all temp.,voltage,freq. 55 watts - 110 watts (G3) or 45 watts - 90 watts (G6, G7, G9, G10 & G11) or 45watts - 90 watts (G8)RUGGEDNESS AT HIGH VSWR No damage into open or shorted load.Figure 1 - Block DiagramLBI-38674F1

POWER CONTROLThe Power Control circuitry performs three basic func-tions. It keys and unkeys the PA, sets the PA output power,and protects the PA against adverse conditions.Keying and Unkeying the PATo key the PA, the digital controller places 5 volts on thePA key line, J201-2. Zero volts on the PA key line causes thePA to unkey. If the control cable (W13) is disconnected, withnothing actively driving the PA key line, the PA will remainunkeyed.PA Output Power SetPA output power is set according to the level of thePower Set line. Four (4) volts on this line will produceminimum power. As the voltage increases toward eight (8)volts, the power will increase to its maximum rated output.The PA output power is initially set at the factory. This isdone by adjusting R43 while injecting a 10 mW signal at J1and applying 8 volts to J201-3. After setting the maximumpower level, changing the output power in done by varyingthe voltage applied on the Power Set line.PA ProtectionThe power control also protects the PA against overtemperature and high VSWR conditions.An over temperature condition exists when the flangetemperature of the final output transistor reaches 80°C. Atthis point the output power will drop below its set level. Theoutput power will continue to drop such that when the flangetemperature reaches 125°C the PA output drops at least 10dB below its set level.Reflected power is limited to 25% of the set power. Ifthe output VSWR degrades to worse than 3:1 the forwardpower will be reduced to limit the reflected power to 25% ofthe set power. The Power Sensor line indicates when the PAis operating in a cutback condition. If the PA is keyed andthe power control is cutting back, the Power Sensor line willdrop to zero (0) volts and the PA alarm light on the stationwill turn on.Theory of OperationPower control of the MASTR III Power Amplifier isaccomplished with a feedback control loop. The three possi-ble feedback signals are: representation of forward power,temperature sensitive scaled representation of forwardpower, or representation of reflected power. These threesignals are input to a diode summing junction which selectsthe largest of the three for use as the feedback.The stripline directional coupler samples the outputpower and produces a voltage, Vf, proportional to the for-ward output power. The power control compares the forwardvoltage, Vf, to a reference voltage at U3. The output of U3controls the current flow thru Q5 and the output of Q203.The collector output of Q203 adjusts the control voltage,Vct1 and Vct2. This control voltage is capable of adjustingthe total PA output power since it provides the first two stagesDC supply to the Low Level Amplifier, U1.During over temperature operation, a scaled repre-sentation of the forward power is maintained constant byvarying the control voltage line. Thermal resistor RT1 sens-ing an increase in temperature causes the output of U3.1 toincrease. If the output of U3.1 becomes larger than the otherfeedback lines, the output of U3.4 will begin to decrease.This in turn will cause the output of Q203 to decreasereducing the supply voltage to U1. Since the scaling is afunction of temperature the power is reduced as the tempera-ture increases.Under VSWR cutback operation the reverse voltage, Vr,representative of the reflected output power is held below athreshold by reducing the control voltage as necessary. If Vrincreases at U3.1 beyond the preset threshold an increase atU3.4 will result. This causes a subsequent reduction in thecontrol voltage to U1. Thus the power control circuit reducesthe output power in order to limit the reflected power to 25%of the set power.Signal InterfaceThe signal interface to the MASTR III Power Amplifieris supported by a six position feedthrough connector, J201,with the following pinout:1–PWR Sensor2–PA Key3–PA PWR Set4–NC5–Ground6–Fil A+Pwr SensorThis line indicates when the PA is experiencing adverseconditions. Under normal operation, while the PA is keyed,this line will be proportional to forward power. Minimumpower (zero watts) corresponds to 2.5 volts while maximumpower corresponds to 4.5 volts. This voltage is not tempera-ture compensated and no effort is made to calibrate thissignal to an absolute power level. It is intended to provide arelative indication of forward power and to discriminatebetween normal and cutback operation.Zero volts on this line, when the PA is keyed, indicates theforward power is cutback. This power cutback may be due tohigh reflected power or may be due to high PA temperatures.This fault condition may indicate a problem with the PA or mayindicate a system problem external to the Power Amplifier.High VSWR may be due to a poor antenna and high tempera-ture may be due to a blocked cabinet vent. Zero volts on thisline, when the PA is keyed, does not indicate zero forwardpower. Zero volts indicates the PA is protecting itself due toadverse conditions. If the adverse condition, either high VSWRor high temperature is eliminated, the power will return tonormal and the PWR SENSOR voltage will rise above 2.5volts.PA Key (Interface Connector pin 2)This line is used to key and unkey the PA. UNKEY = 0volt and KEY = 5 volts. The driver of this line must be capableof supplying 5 volts at 1.0 mA. The appropriate key sequencerequires RF from the transmit synthesizer be input to the PAbefore the KEY line is energized.PA PWR Set (Interface Connector pin 3)This line is used to set the RF Power Output of the PA.Minimum power output equals 4 volts and maximum poweroutput equals 8 volts. The driver of this line must be capableof supplying 8 volts at 1.0 mA.Fil A+ (Interface Connector pin 6)This line provides the filtered supply voltage for the PowerControl. The driver of this line must be capable of supplying13.4 volts ±20% at 100 mA.SYMPTOM AREAS TO CHECK INDICATIONS1. No Power or low Power at 1. Measure the transmitter output The presence of power at this port Antenna Port. power before the duplexer or is an indication of a defective antenna switch (for simplex mode). duplexer, switch, or cables.2. Measure the transmitter output The presence of power at this port power before the low pass filter. is an indication of a defective filter or cables.3. Measure the transmitter output The presene of power at this port power before the optional isolator is an indication of a defective isolatorat the PA output port. or cables.2. No power at PA output port 1. Station is in receive mode.and PA ALARM is OFF.3. No power at PA output port 1. No RF input to PA. Check TX Synthesizer should deliverand PA ALARM is ON. connection between PA and TX a minimum of 10 mWSynthesizer. (10 dBm) to the PA.2. Check the logic or DC inputs tothe PA from the Interface Boardthrough J201.a. J201-2 PA KEY 5volts during transmitb. J201-3 POWER SET 4 volts to 8 volts (4 voltsrepresents zero RF power)c. J201-6 13.8 VF 13.8 Vdc ±20%3. Defective PA Replace PATROUBLESHOOTING GUIDELBI-38674F2

SYMPTOM AREAS TO CHECK INDICATIONS4. Low power at PA output port 1. Low RF input to PA from TX Power should be a minimum of 10 and PA ALRAM is OFF. Synthesizer. mW (10 dBm).2. Check the voltage on J201-3 For minimal output power, this (POWER SET). voltage should be above 7 volts.3. Check the power supply voltage Voltage should be minimal 13.4 on the collector of Q1, Q2 Vdc.and Q34. One of the two final PA Replace the defective transistor.transistors (Q2 or Q3) isdefective.5. Low power at PA output port 1. Check for over temperature and/ The power control circuit protectsand PA ALARM is ON. or a high VSWR condition due to the PA by cutting back the power. a mismatch at the output port. In case of a mismatch, refer tosymptom 1.TROUBLESHOOTING GUIDE (cont’d)PARAMETER REFERENCE READINGS(50 ohm, -30°C to +60°C) SYMBOL (volts DC)SUPPLY VOLTAGE A+ 13.4 V ±20%CONTROL VOLTAGE Vct1 0 - 12 VFORWARD VOLTAGE Vf 3 - 7 VREVERSE VOLTAGE Vr 2 - 6 VPOWER SENSE J201-1 2.5 - 4 VPA KEY J201-2 5 VPOWER SET J201-3 4 - 8 V13.8 VF J201-6 13.8 V ±20%UHF POWER AMPLIFIER VOLTAGE CHARTGroup Low Mid HighFrequency G3G6G7G8G9G10G11450 MHZ403 MHZ425 MHZ380 MHZ470 MHZ492 MHZ410 MHZ460 MHZ414 MHZ437 MHZ390 MHZ482 MHZ502 MHZ420 MHZ470 MHZ425 MHZ450 MHZ400 MHZ494 MHZ512 MHZ430 MHZVct 1 (Volts DC) G3G6G7G8G9 & G10G117 - 10 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts4 - 6 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 VoltsVf (Volts DC) G3G6G7G8G9 & G10G115 - 7 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts5 - 7 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts5 - 7 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 VoltsVr (Volts DC) G3G6G7G8G9 & G10G112 - 3 Volts2 - 3 Volts2 - 3 Volts2 - 3 Volts2 - 3 Volts2 - 3 Volts2 - 3 Volts2 - 3 Volts2 - 3 Volts2 - 3 Volts2 - 3 Volts2 - 3 Volts2 - 3 Volts2 - 3 Volts2 - 3 Volts2 - 3 Volts2 - 3 Volts2 - 3 VoltsJ201 - 1 (Volts DC) G3G6G7G8G9 & G10G112.5 - 4 Volts2.5 - 4 Volts2.5 - 4 Volts2.5 - 4 Volts2.5 - 4 Volts2.5 - 4 Volts2.5 - 4 Volts2.5 - 4 Volts2.5 - 4 Volts2.5 - 4 Volts2.5 - 4 Volts2.5 - 4 Volts2.5 - 4 Volts2.5 - 4 Volts2.5 - 4 Volts2.5 - 4 Volts2.5 - 4 Volts2.5 - 4 VoltsJ201 - 3 (Volts DC) G3G6G7G8G9 & G10G116 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 Volts6 - 8 VoltsJ201- 6 (Volts DC) G3G6G7G8G9 & G10G1113.4 Volts13.4 Volts13.4 Volts13.4 Volts13.4 Volts13.4 Volts13.4 Volts13.4 Volts13.4 Volts13.4 Volts13.4 Volts13.4 Volts13.4 Volts13.4 Volts13.4 Volts13.4 Volts13.4 Volts13.4 VoltsUHF POWER AMPLIFIER TYPICAL VOLTAGE READINGS(50 ohm, room temperature, 13.4 Vdc supply voltage, and rated output)LBI-38674F3

FREQUENCY STANDARD ADJUSTABLE WITH WITH WITH DUPLEXERMHz @J2 RANGE DUPLEXER ISOLATOR AND ISOLATOR@J104450-470 110W 65-130W 75W 100W 70W425-450 90W 55-110W 60W 82W 55W403-425 90W 55-110W 60W 82W 55W380-400 75W 45-90W 50W 68W 47W410-430 90W 55-110W 60W 82W 55W470-494 90W 55-110W 60W 82W 55W492-512 90W 55-110W 60W 82W 55WRATED POWER FOR MASTR III UHF BASE STATIONLBI-38674F4

ASSEMBLY DIAGRAMPOWER AMPLIFIER ASSEMBLY19D902797G3, G6, G7, G8, G9, G10 & G11(19D902797 Sh. 3, Rev. 10)LBI-38674F5

ASSEMBLY DIAGRAMPOWER AMPLIFIER ASSEMBLY19D902797G3, G6, G7, G8, G9, G10 & G11(19D902797 Sh. 2, Rev. 10)COVER ASSEMBLY19B801659G3(19B801659, Sh. 2, Rev. 3)LBI-38674F6

ASSEMBLY DIAGRAMSLOW PASS FILTER MODULE19D902856G3(19D902856 Sh. 1, Rev. 0)LBI-38674F7

PARTS LIST & PRODUCTION CHANGESLOW PASS FILTER MODULE19D902856G3 & G9ISSUE 2SYMBOL PART NO. DESCRIPTION R8thruR1019B800607P103 Metal film: 10K ohms ±5%, 1/8 w.R11 19B800607P223 Metal film: 22K ohms ±5%, 1/8 w.R12thruR1819B800607P103 Metal film: 10K ohms ±5%, 1/8 w.R19andR2019B800607P472 Metal film: 4.7K ohms ±5%, 1/8 w.R21thruR2319B800607P102 Metal film: 1K ohms ±5%, 1/8 w.R24thruR2619B800607P103 Metal film: 10K ohms ±5%, 1/8 w.R27 19B800607P822 Metal film: 8.2K ohms ±5%, 1/8 w.R28andR2919A143832P6 Power: 100 ohms ±5%, 40 w.R30 19B800607P750 Metal film: 75 ohms ±5%, 1/8w. R31 19B800607P330 Metal film: 33 ohms ±5%, 1/8 w.R32 19A700050P17 Wirewound: 2.2 ohms ±10%, 2 w. (Used in G3, G9, and G10).R33 19B800607P392 Metal film: 3.9K ohms ±5%, 1/8 w.R34 19B801486P100 Metal film: 10 ohms ±5%, 1/2 w.R35 19A700050P17 Wirewound: 2.2 ohms ±10%, 2 w. (Used in G3, G9).R36 19B801486P101 Metal film: 100 ohms ±5%, 1/2 w. (Used in G40, G3, and G6).R37 19B801486P331 Metal film: 330 ohms ±5%, 1/2 w. (Used in G3, G6-G9, G11).R38 19B800607P223 Metal film: 22K ohms ±5%, 1/8 w.R39andR4019B800607P100 Metal film: 10 ohms ±5%, 1/8 w.R41 19A702931P333 Metal film: 21.5K ohms ±1%, 200 VDCW, 1/8 w.R42 19A702931P293 Metal film: 9090 ohms ±1%, 200 VDCW, 1/8 w.R43 19A700109P5 Variable, cermet: 25 ohms to 10K ohms ±20%, 1/4 w.R44thruR4619B801486P101 Metal film: 100 ohms ±5%, 1/2 w.R47andR4819B801486P750 Metal film: 75 ohms ±5%, 1/2 w.R49 19B801486P101 Metal film: 100 ohms ±5%, 1/2 w. (Used in G3, G6-G9, G11).R50 19B800607P1 Metal film: Jumper. (Used in G8, G9, G10 and G11).R51 19B801486P331 Metal film: 330 ohms ±5%, 1/2 w.(Used in G3, G6-G9, G11).R52 19B801486P100 Metal film: 10 ohms ±5%, 1/2 w.R53 19B800607P1 Metal film: Jumper.R54 19B800607P472 Metal film: 4.7 ohms ±5%, 1/8 w.R55 19B800607P103 Metal film: 10K ohms ±5%, 1/8 w.R56 19B800607P330 Metal film: 33 ohms ±5%, 1/8 w.R57 19B800607P222 Metal film: 2.2 ohms ±5%, 1/8 w.R58andR5919A700113P7 Composition: 4.7 ohms ±5%, 1/2 w (Used in G10).- - - - - - - - - - - - - - THERMISTOR - - - - - - - - - - - - - - RT1 19A705813P2 Thermistor: sim to AL03006-58.2K-97-G100.- - - - - - - - - - - VOLTAGE REGULATORS - - - - - - - - - - -VR1andVR219A700083P102 Silicon: 5.1 Volt Zener; sim to BZX84-C5V1.- - - - - - - - - - - - - - CAPACITORS - - - - - - - - - - - - - -C1 19A116708P2 Ceramic feedthru: 0.01 µF -0 +100%, 500 VDCW; sim to Erie327-050-X5W0103P.SYMBOL PART NO. DESCRIPTION - - - - - - - - - - - - - - JACKS - - - - - - - - - - - - - -J1 Part of W1.J104 7777145P5 Receptacle: sim to Amphenol 82-97.- - - - - - - - - - - - - - TRANSISTORS - - - - - - - - - - - - - -Q1 344A3948P1 Silicon, NPN: UHF Amplifier; sim to Motorola MRF 650.Q2andQ3344A4134P1 Silicon, NPN: UHF Amplifier.Q203 19A700055P1 Silicon, PNP: Darlington; sim to TIP-125.- - - - - - - - - - - - - - RESISTORS - - - - - - - - - - - - - -R28andR2919A143832P6 Power: 100 ohm 5%, 40 w.- - - - - - - - - - -INTEGRATED CIRCUITS - - - - - - - - - - - -U1 19A705457P2 PA module: 440-470 MHz; sim to M57704H. (Used in G3).U1 19A705457P1 PA module: 400-450 MHz; sim to M57704M. (Used in G7).U1 19A705457P3 PA module: 470-512 MHz; sim to M57704SH. (Used in G9and G10).U1 19A705457P7 PA module: 380-400 MHz; sim to M57704UL. (Used in G8).U1 19A705457P4 PA module: 400-420 MHz; sim to M57704L. (Used in G6).U2 19A702293P3 Linear: Dual Op Amp; sim to LM358D.U3 19A701789P4 Linear: Quad Op Amp; sim to LM224D.U7 344A3907P1 Monolithic microwave IC (MMIC): sim to Avantek MSA-1105.U100 19A705532P2 Integrated Circuit, Linear (Positive Voltage Regulator): sim toMC78T15CT.- - - - - - - - - - - - - - - - CABLES - - - - - - - - - - - - - - - -W1 19B801529G4 RF Input Cable. Includes the following:19B800560P2 RF Cable.19A705512P3 Connector, RF SMB series: sim to AMP 228213-1.19A115938P1 Connector, coaxial: (BNC Series); sim to Amphenol 31-318.W4 19B801695G11 Power Cable. Includes the following:19B209268P115 Solderless terminal.19B209260P11 Solderless terminal.19A115959P2 Wire, stranded.19A701503P2 Cable: battery, red.19A701503P10 Cable: battery, black.19B209268P116 Solderless terminal.W10 19B801937P1 Power cable.W13 19B801739P1 Power control cable.- - - - - - - - - - - - - MISCELLANEOUS - - - - - - - - - - - -2 19D902420P6 Heatsink.5 19A702381P510 Screw, thread forming: TORX DRIVE No. M3.5 0.6 x 10.6 7139898P3 Nut, hex, brass: No. 1/4-28.11 19A702364P310 Machine screw, TORX Drive: No. M3-0.5 x 10.14 19B209268P113 Terminal, solderless: sim to AMP 2-34835-4. (Used in G11).19A115959P2 Wire, stranded. (Used in G11).19B209268P116 Solderless terminal. (Used in G11).15 7147306P2 Insulator.16 19A700136P7 Insulated sleeving.21 19A701863P27 Clip, loop.22 19A701312P5 Flatwasher: M3.5.28 19A702364P316 Machine Screw: Pan Head, Steel.29 19A700034P4 Nut, hex: No. M3 x 0.5MM.30 19A700033P5 Lock washer, external tooth: No. 3.SYMBOL PART NO. DESCRIPTION 35 19A705469P1 Insulator Plate, TO-220.36 19A700068P1 Insulator, bushing.37 19A134455P3 Flat washer.38 19B801659G3 Cover (see separate parts list).41 19A700033P6 Loackwasher, external tooth, M3.5.45 N405P5B6 Lockwasher.46 19A701312P4 Flatwasher: 3.2 ID.50 19A702381P408 Tap screw, TORX Drive, M3-0.5 x 8.51 19A705106P1 Resistor Spacer.COVER19B801659G32 19D902421P1 Power Amplifier Cover.4 19A702381P522 Screw, thread forming:5 19A701365P4 Washer.11 19A149969P3 Shield.13 5493477P9 Axial fan.14 5493477P10 Grille.15 N80P13028B6 Machine screw.16 N210P21B6 Machine nut.17 19A701312P5 Flatwasher: M3.5.18 19A701863P10 Clip, loop.20 19A702364P410 Machine screw.24 N405P37B6 Lock washer.25 L401P23B6 Split washer.26 19A700034P5 Hex nut.SYMBOL PART NO. DESCRIPTION - - - - - - - - - - - - - JACKS - - - - - - - - - - - - -J1andJ27777145P5 Receptacle: sim to Amphenol 82-97.- - - - - - - - - - - - - MISCELLANEOUS - - - - - - - - - - - -2 19D903063P1 Casting.3 19D903064P1 Casting.5 19A702381P513 Screw, thread forming: TORX, No. M3.5 - 0.6 X 13.6 19A702364P210 Machine screw, metric: M2.5-.45 x 10.7 19A134455P3 Flatwasher.8 19A700032P3 Lockwasher, tooth, steel, metric: 2.5.UHF FILTER BOARD19D902853G3- - - - - - - - - - - - - CAPACITORS - - - - - - - - - - - - -C1thruC319A700006P2 Mica: 5.6 pF ±10%, 100 VDCW; sim to Underwood3HS0020.C4 19A700006P1 Mica: 4.7 pF ±10%, 100VDCW.C5 19A700006P2 Mica: 5.6 pF ±10%, 100 VDCW; sim to Underwood3HS0020.- - - - - - - - - - - - - INDUCTORS - - - - - - - - - - - - -L1andL219C320618P7 Coil.SYMBOL PART NO. DESCRIPTION L3thruL619B227929P1 Coil.UHF FILTER BOARD19D902853G9- - - - - - - - - - - - CAPACITORS - - - - - - - - - - - -C1 19A700006P1 Mica: 4.7 pF ±10%, 100 VDCW.C2andC319A700006P3 Mica: 6.8 pF ±10%, 100VDCW.- - - - - - - - - - - - INDUCTORS - - - - - - - - - - - -L1thruL419C320617P17 Coil.- - - - - - - - - -MISCELLANEOUS - - - - - - - - - -11 19A702455P5 Nut, self clinching.PRODUCTION CHANGESChanges in the equipment to improve performance or to simplifycircuits are identified by a "Revision Letter" which is stamped afterthe model number of the unit. The revision stamped on the unitincludes all previous revisions. Refer to the Parts List for thedescriptions of parts affected by these revisions.REV. A POWER AMPLIFIER 19D902797G3POWER AMPLIFIER BOARD 19D902794G3To make unit ETS compliant.C17, C44, C45 were 19A702052P33.C50 was 0.068 µF (19A702052P24).C61 was 8.2 pF (19A702061P12).C62 was 27 pF (19A702061P33).C84 was 1000 pF (19A705108P40).D1, D2, D3 were (19A700047P3)L15 thru L17 were (19A700024P37).L24 was 15nH (19A705470P3).R33 was 5.6K (19B800607P562).R34 was 3.9 ohms composition (19A700113P5).L26 and L27 were removed.C48, C49, C63, C74 were removed.C1, (19A702052P26) was added.C25, C26 (344A3126P38) were added.R37, R51 (19B801486P331) were added.R52 (19B801486P100) was added.Q7 was 19A701940P1.RT1 (19A705813P2) was added.VR2 (19A700083P102) was added.REV. B POWER AMPLIFIER 19D902797G3POWER AMPLIFIER BOARD 19D902794G3To update PWB for new split.PWB changedC26 was 100 pF (344A3126P38).C81 was 100 pF (344A3126P38).C27 thru C29 added: 8.2 pF (344A3126P11).C34 and C35 added: 12 pF (344A3126P15).R36 was 150 ohms (19B801486P151).R44 thru R46 were 150 ohm (19B801486P151).R47 and R48 were 39 ohm (19B801486P390).R32 and R35 added: 2.2 ohm (19A700050P17).* COMPONENTS, ADDED, DELETED OR CHANGED BY PRODUCTION CHANGESLBI-38674F9

PRODUCTION CHANGES AND OUTLINE DIAGRAMPOWER AMPLIFIER BOARD A119D902856G3, G6, G7, G8, G9, G10 & G11(19D902794 Sh. 2, Rev. 14)COMPONENT SIDEPRODUCTION CHANGES - CONT.REV. C POWER AMPLIFIER 19D902797G3POWER AMPLIFIER BOARD 19D902794G3To update PWB for new band splits.REV. D POWER AMPLIFIER 19D902797G3POWER AMPLIFIER BOARD 19D902794G3To update PWB for new band splits and add powermonitor circuitry. Added U2, C48, R54, R53, R55.REV. A POWER AMPLIFIER 19D902797G6To update PWB to new band splits.REV. A POWER AMPLIFIER 19D902797G7POWER AMPLIFIER BOARD 19D902794G7To update PWB to new band splits and add powermonitor circuitry. Added U2, C48, R54, R53, R55.REV. A POWER AMPLIFIER 19D902797G8, G9, G11POWER AMPLIFIER BOARD 19D902794G8, G9, G11REV. B POWER AMPLIFIER 19D902797G6, G7POWER AMPLIFIER BOARD 19D902794G6, G7REV. E POWER AMPLIFIER 19D902797G3POWER AMPLIFIER BOARD 19D902794G3To update PWB to new band splits for 492-512 MHz.REV. B POWER AMPLIFIER BOARD 19D902797G11Improve reliability.C67 was 39 pF (19A700006P50).LBI-38674F10

SCHEMATIC DIAGRAMPOWER AMPLIFIER ASSEMBLY19D902797G3, G6, G7, G8, G9, G10 & G11(19D903622 Sh. 1, Rev. 11)LBI-38674F11

OUTLINE AND SCHEMATIC DIAGRAMSLOW PASS FILTER MODULE19D902856G3(19D903623 Sh.1, Rev. 1)(19D902853, Sh. 2, Rev. 0)(19D903638, Component Side, Rev. 0)COMPONENT SIDE(19D902853, Sh. 2, Rev. 0)(19D903638, Solder Side, Rev. 0)SOLDER SIDEREF. DES. 380-400 MHz403-425 MHz 425-450 MHz 450-470 MHz 470-494 MHz 492-512 MHz 410-430 MHzC27 10.0 pf 12.0 pf 10.0 pf not used not used not used 12.0 pfC28 15.0 pf 12.0 pf 8.2 pf not used not used not used 10.0 pfC29 15.0 pf 12.0 pF 8.2 pF not used not used not used 10.0 pfC30 12.0 pF not used not used 8.2 pF 8.2 pF 8.2 pF not usedC31 12.0 pF not used not used 8.2 pF 8.2 pF 8.2 pF not usedC32 not used not used not used 3.3 pF not used not used not usedC33 not used not used not used 3.3 pF not used not used not usedC34 not used 15.0 pF 15.0 pF not used not used not used 15.0 pFC35 not used 15.0 pF 15.0 pF not used not used not used 15.0 pFC36 3.9 pF 4.7 pF not used not used not used not used 4.7 pFC58 12.0 pF 12.0 pF 12.0 pF 8.2 pF 5.6 pF 5.6 pF 12.0 pFC65 not used not used not used 8.2 pF 4.7 pF 4.7 pF not usedC66 47.0 pF 39.0 pF 39.0 pF 33.0 pF 27.0 pF 27.0 pF 39.0 pFC67 47.0 pF 47.0 pF 39.0 pF 36.0 pF 27.0 pF 27.0 pF 47 pFC68 47.0 pF 39.0 pF 39.0 pF 33.0 pF 27.0 pF 22.0 pF 39.0 pFC69 47.0 pF 47.0 pF 39.0 pF 36.0 pF 27.0 pF 22.0 pF 43.0 pFC87 56.0 pF 47.0 pF 43.0 pF 39.0 pF 33.0 pF 33.0 pF 47.0 pFC88 51.0 pF 51.0 pF 43.0 pF 39.0 pF 33.0 pF 33.0 pF 51.0 pFC89 51.0 pF 51.0 pF 43.0 pF 39.0 pF 33.0 pF 33.0 pF 51.0 pFC90 56.0 pF 47.0 pF 43.0 pF 39.0 pF 33.0 pF 33.0 pF 47.0 pFC91 51.0 pF 47.0 pF 36.0 pF 33.0 pF 33.0 pF 33.0 pF 43.0 pFC92 51.0 pF 43.0 pF 39.0 pF 33.0 pF 27.0 pF 27.0 pF 43.0 pFC93 51.0 pF 43.0 pF 39.0 pF 33.0 pF 27.0 pF 27.0 pF 43.0 pFC94 51.0 pF 47.0 pF 36.0 pF 33.0 pF 33.0 pF 33.0 pF 43.0 pFL2 BEAD BEAD BEAD not used not used not used BEADL3 AIR COIL AIR COIL AIR COIL not used not used not used AIR COILL5 BEAD BEAD BEAD not used not used not used BEADL6 AIR COIL AIR COIL AIR COIL not used not used not used AIR COILR32 not used not used not used 2.2 pF 2.2 pF not used not usedR35 not used not used not used 2.2 pF 2.2 pF not used not usedC37 2.2 pF not used not used not used not used not used not usedR53 not used 0 0 0 not used not used not usedR50 0 not used not used not used 0 0 0C41 not used not used not used not used not used not used 100.0 pFC46 not used not used not used not used 8.2 pF 10.0 pF not usedC47 not used not used not used not used 8.2 pF 10.0 pF not usedR58 not used not used not used not used not used 4.7 pF not usedR59 not used not used not used not used not used 4.7 pF not usedR49 100 100 100 100 100 not used 100R37 330 330 330 330 330 not used 330R51 330 330 330 330 330 not used 1200 pFC84 1200 pF 1200 pF 1200 pF 1200 pF 1200 pF not used 1200 pFL1 3 turn 3 turn 3 turn 3 turn 3 turn 1 turn 3 turnPOWER AMPLIFIER ASSEMBLY19D902797G3, G6, G7, G8, G9,G10 & G11(19D903622 Sh.2 Rev. 11)TABLE ILBI-38674F12

SCHEMATIC DIAGRAM & IC DATAU119A705457P1, P2 AND P4PA Amplifier ModuleU319A701789P4Quad Op-AmpU10019A705532P2Voltage RegulatorU7344A3907P1MMIC AmplifierLOW PASS FILTER MODULE470 - 512 MHz19D902856G9(19B804157, Rev. 0)LBI-38674F13

LBI-38675EMaintenance ManualMASTR® IIIRF PACKAGE, UHF380-512 MHzTABLE OF CONTENTSTRANSMIT SYNTHESIZER . . . . . . . LBI-38671RECEIVE SYNTHESIZER . . . . . . . . LBI-38672RECEIVE RF MODULE . . . . . . . . . . LBI-38673 LBI-39129IF MODULE . . . . . . . . . . . . . . . . LBI-38643 LBI-39123POWER AMPLIFIER . . . . . . . . . . . LBI-38674ericssonz

Copyright© July 1992, Ericsson GE Mobile Communications, Inc.TABLE OF CONTENTSPageCONVENTIONALOPTIONS AND ACCESSORIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3ADDITIONAL OPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3TONE & DC REMOTE CONTROLLED STATIONS . . . . . . . . . . . . . . . . . . . . . . . 3REGULATORY DATAEDACS AND CONVENTIONAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5TRANSMITTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6RECEIVER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6MODULE NUMBERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7ANTENNA SWITCH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9ILLUSTRATIONSFIGURE 1 - 69" & 37" CABINET MOUNT . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8This manual covers Ericsson and General Electric products manufactured and sold by Ericsson Inc.NOTICE!This manual is published by Ericsson Inc., without any warranty. Improvements and changes to this manual necessitatedby typographical errors, inaccuracies of current information, or improvements to programs and/or equipment, may bemade by Ericsson Inc., at any time and without notice. Such changes will be incorporated into new editions of this manual.No part of this manual may be reproduced or transmitted in any form or by any means, electronic or mechanical, includingphotocopying and recording, for any purpose, without the express written permission of Ericsson Inc.The software contained in this device is copyrighted by the Ericsson Inc. Unpublished rights are reserved under thecopyright laws of the United States.NOTICE!Repairs to this equipment should be made only by an authorized service technician or facility designated by the supplier.Any repairs, alterations or substitution of recommended parts made by the user to this equipment not approved by themanufacturer could void the user’s authority to operate the equipment in addition to the manufacturer’s warranty.NOTICE!LBI-38675E2

CONVENTIONAL OPTIONS and ACCESSORIESProgrammable Options• Transmit Frequencies• Receive Frequencies• Channel Spacing• Channel Guard Digital and Tone• Channel Guard Disable• Repeater Disable• Intercom Function• Type 90• DTMF Decode• Morse Code ID• Squelch Tail Elimination (STE)• Carrier Control Timer• Station Control• DC Control• Tone Control• Repeater• DC/Repeat•Tone/Repeat• 2 or 4 Wire Audio• Scan Additional Options• Service Microphone• Antenna Multicoupler• 50 Hz Power Supply• Duplexer• Antenna Relay (VHF/UHF)• Combiner• Isolator• Squelch Operated Relay• Remote Controllers• Battery Standby (VHF/UHF)• Battery Charger (VHF/UHF)• Gel Cell Battery (VHF/UHF)• Voice Guard Encryption• Aegis DigitalCONVENTIONAL TONE & DC REMOTE CONTROLLED STATIONSAUDIO (Line to Transmitter)Line Terminating Impedance: 600 WLine Level (Adjustble): -20 dBm to +7 dBmFrequency Response: ± 3 dB @ 300-3000 HzTONE CONTROLFunction Tones: 1050,1150,1250,1350,1450,1550,1650, 1750,1850,1950 & 2050 HzSecur-it Tone & Transmit Tone: 2175 HzTransmitted 2175 Hz Tone Level: 20 dB Below VoicePermissible Control Line Loss@2175 Hz: 30 dB ContinuedLBI-38675E3

CONVENTIONAL TONE & DC REMOTE CONTROLLED STATIONS - Cont.AUDIO (Receiver-to-Line)Audio Amplifier Input Impedance: 10 KΩ Input Level: 1 V RMS (For 5 kHz Deviation)Output Impedance to Line: 600 ΩOutput Level to Line Voice (1 kHz ref): +7 dBm (Adjustable) Tone (1 kHz ref): +7 dBm (Ref. 7 dBm)Freqency Response: +1 dB and -3dB @ 300-3000 HzHum and Noise, Noise Squelch: -55 dB (Ref. 7 dBm) Tone Squelch: -30 dB (Ref. 7 dBm)DC CONTROL Control Control Currents: -2.5, ± 6 & ± 11 mALine Loop Resistance (maximum): 11 KΩ (Includes 3K Termination)REGULATORY DATA EDACS and CONVENTIONALFCC FILING DATA (for cabinet or open rack mounting)FREQUENCYBAND POWER OUTPUT(Internally Adjustable)FREQ. STABILITYAND MODULATIONTYPEAPPLICABLE TO FCC RULES PARTNUMBERSFCC FILLING NUMBER403-430 45 to 90 W (Freq. Mod. PLL Exc.)1.0 PPM 22,90,80,74 AXATR-307-A425-450 45 to 90 W (Freq. Mod. PLL Exc.)1.0 PPM 22,90,80,74 AXATR-307-A2450-470 50 to 100W (Freq. Mod. PLL Exc.)1.0 PPM 22,90,80,74 AXATR-307-B2470-494492-512 45 to 90 W (Freq. Mod. PLL Exc.)1.0 PPM 22,90,80,74 AXATR-307-C2AXATR-307-D2DOC FILING DATAFREQUENCYBAND TYPE NUMBER APPLICABLE SPEC403-430 TR-307 RSS-119425-450 TR-307 RSS-119450-470 TR-307 RSS-119470-494, 492-512 NA NALBI-38675E4

GENERALCABINET INDOOR CABINET (Floor Mount)37" (CNV) 69"SIZE [in. (mm)]Height:Width:Depth:Weight (min) [(lb. (Kg)] Continuous Duty Packed , Domestic ShippingNumber of Rack UnitsMaximum Units w/Power SupplyMaximum Units w/o Power Supply37.0 (940)21.5 (550)18.25 (460)150 (68)165 (75)172269.1 (1750)23.1 (590)21 .0 (533)300 (136)317 (147)3334SERVICE SPEAKER: 1 Watt @ 8ΩSERVICE MICROPHONE: Transistorized DynamicDC 5A @ 120 VAC or 3A @ 230 VACDUTY CYCLE (EIA) Continuous: Transmit/Receive - 100%AMBIENT TEMPERATURE: -30oC to +60oC(or full spec performance per EIA) (-22oF to +140oF)HUMIDITY (EIA): 90% @ 50oC (122oF)INPUT POWER SOURCE: 120 VAC (± 20%) orOptional: 230 VAC (± 15%), 50 HzStandby Battery Source: 13.8 VDC, 100 AH (min.)ANTENNA CONNECTIONS: Type NLENGTH OF AC POWER CABLE: 10 ft (3048mm)METERING: Provided through Handset or TQ0619 Utility Software.ALTITUDEOperable: Up to 15,000 ft (4,570 m)Shipable: Up to 50,000 ft (15,250 m)SOURCE POWER DRAIN UHFFrequency Range(MHz) 380-400 403-430 425-450 450-470 470-494 492-512AC Input Power: 5A @ 120 VAC or 3A @ 230 VACDC Input Power: VDCTx (full / half power): 13.8Rx only: 13.8Tx (full / half power): 26.4EDACS Applications: 13.833/25A2 A2 A33/25A2 A2 A33/25A2 A2 A33/25A2 A2 A33/25A2 A2 A33/25A2 A2 ANOTE: One Rack Unit equals 1.75 inches, Stations occupy 8 rack units of cabinet space. LBI-38675E5

TRANSMITTERUHFFREQUENCY RANGE (MHz)RATED POWER OUTPUT (Watts):RF OUTPUT IMPEDANCE (W):CONDUCTED SPURIOUS & HARMONIC EMISSION (dBm):FREQUENCY STABILITY (%):MODULATION DEVIATION (kHz): 16F3 & 16F9 20F5Y & 20F9Y (VHF & UHF)FM NOISE (dB):CHANNEL STEPS (kHz)FREQUENCY SPREAD Full Spec (MHz)380-400 403-430 425-450 450-470 470-494 492-5127550-36±0.00010 to ± 5-556.25209050-36±0.00010 to ± 5-556.25229050-36±0.00010 to ± 5-556.252510050-36±0.00010 to ± 5-556.25209050-36±0.00010 to ± 5-556.25249050-36±0.00010 to ± 5-556.2520RECEIVERUHFFREQUENCY RANGE (MHz)RF INPUT IMPEDANCE (W):CHANNEL SPACING (kHz):SENSITIVITY (dBm) EIA 12 dB SINAD: Threshold Squelch (dBm):SELECTIVITY EIA 2-Signal (dB) 12.5 kHz: 25 kHz: 380-400 403-430 425-450 450-470 470-494 492-5125012.5/25-115(0.40 µV)-118(0.28 µV)-80-905012.5/25-116(0.35 µV)-119(0.25 µV)-80-905012.5/25-116(0.35 µV)-119(0.25 µV)-80-905012.5/25-116(0.35 µV)-119(0.25 µV)-80-905012.5/25-116(0.35 µV)-119(0.25 µV)-80-905012.5/25-116(0.35 µV)-119(0.25 µV)-80-90ContinuedAUDIO DISTORTION (@ 1 kHz): Less than 3%NUMBER OF CHANNELS (Conventional): up to 16AUDIO RESPONSE (pre-emphasis): Within +1 and -3 dB of 6dB/octave, 300 to 3000 Hz per EIA.NOTE: Rated power output is measured at the transmitter power amplifier output connector per FCC Type Acceptance fillinginformation. Any customer- required optional items such as power measuring devices and/or duplexers will introduce lossbetween the transmitter output connector and the station cabinet output connector. This loss will reduce the available powerat the station connector.LBI-38675E6

RECEIVER - Cont.UHFFREQUENCY RANGE (MHz)FREQUENCY STABILITY (%):SIGNAL DISPLACEMENTBANDWIDTH (kHz):INTERMODULATION (dB) 12.5 kHz: 25 kHz: 30 kHz: ETSISPURIOUS & IMAGE REJECTION (dB):FREQUENCY SPREAD Full Specs. (MHz): 3 dB Degradation in Sensitivity (MHz):380-400 403-430 425-450 450-470 470-494 492-512±0.0001±2-80-85-1002.03.0±0.0001±2-80-85-1002.03.0±0.0001±2-80-85-1002.03.0±0.0001±2-80-90-85-1002.03.0±0.0001±2-80-90-1002.03.0±0.0001±2-80-90-1002.03.0AUDIO RESPONSE (de-emphasis): Within +2 and -8 dB of 6 dB/octave (@ Local Speaker), 300 to 3000 Hz per EIA.Within +1 and -3 dB of 6 dB/octave (@ Line Output), 300 to 3000 Hz per EIA.AUDIO OUTPUT: 1 Watt at less than 3% distortion @ 1000 Hz, 25 kHz ChannelMODULE NUMBERSTRANSMIT SYNTHESIZER (450-470 MHz) ........................................19D902780G3(425-450 MHz) ........................................19D902780G7(403-425 MHz, 410-430MHz)................19D902780G6(380-400 MHz) ........................................19D902780G8(470-494 MHz) ........................................19D902780G9(492-512 MHz) .......................................19D902780G10RECEIVE SYNTHESIZER (450-470 MHz, 403-425 MHz,410-430 MHz)..........................................19D902781G3(425-450 MHz, 470-494 MHz)...............19D902781G7(380-400 MHz) ........................................19D902781G8(492-512 MHz) .......................................19D902781G10RX FRONT END MODULE (450-470 MHz) ........................................19D902782G3(425-450 MHz) ........................................19D902782G7(403-425 MHz) ........................................19D902782G6(410-430 MHz) .......................................19D902782G11(380-400 MHz) ........................................19D902782G8(470-494 MHz) ........................................19D902782G9(492-512 MHz) .......................................19D902782G10IF MODULE ...................................................................19D902783G1(470-494 MHz, 492-512 MHz)...............19D902783G7ContinuedLBI-38675E7

MODULE NUMBERS - Cont.POWER AMPLIFIER (450-470 MHz).........................................19D902797G3(425-450 MHz).........................................19D902797G7(403-425 MHz).........................................19D902797G6(410-430 MHz.........................................19D902797G11(380-400 MHz).........................................19D902797G8(470-494 MHz).........................................19D902780G9(492-512 MHz)........................................19D902780G10LOW PASS FILTER ...................................................................19D902856G1(470-512 MHz).........................................19D902780G9ANTENNA SWITCH ................................................................... 19B235897P2DUPLEXER (440-470 MHz).......................................... 344A4047P1Fig 1 - 69" & 37" Cabinet Mount8

ACCESSORIESANTENNA SWITCH19B235897P2LBI-38675E9

Ericsson Inc.Private Radio SystemsMountain View RoadLynchburg, Virginia 245021-800-528-7711 (Outside USA, 804-592-7711) Printed in U.S.A.LBI-38675E

MAINTENANCE MANUAL FOR21.4 MHz RECEIVER IF MODULE12.5/25 kHz CHANNEL SPACING19D902783G7 & G11DESCRIPTIONThe MASTR III Receiver IF Module provides amplifi-cation and demodulation of the 21.4 MHz IntermediateFrequency signal. The IF Module also includes the re-ceiver squelch circuitry. However, it does not include de-emphasis or squelch audio gating circuits. Figure 1 is ablock diagram showing the functional operation of the IFModule.The IF Module circuitry contains the following:•A 50 ohm input impedance IF Amplifier•A chain of two crystal filters and an integratedcircuit IF amplifier•An integrated circuit containing a crystal oscillator,mixer, limiter, and quadrature detector •A variable gain AF amplifier•A squelch circuit•A fault detector circuit•An integrated circuit voltage regulator•An address decoderTABLE OF CONTENTSPageDESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Front CoverGENERAL SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1CIRCUIT ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1INPUT MATCHING NETWORK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1CRYSTAL FILTERS, IF AMPLIFIERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1OSCILLATOR/MIXER/DETECTOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1AUDIO AMPLIFIER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1SQUELCH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Buffer Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Bandpass Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Noise Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2DC Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Schmitt Trigger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2FAULT DETECTOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2VOLTAGE REGULATOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2ADDRESS DECODER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2RECOMMENDED TEST EQUIPMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2ALIGNMENT PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3ASSEMBLY DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3OUTLINE DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4SCHEMATIC DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5IC DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11PRODUCTION CHANGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Back CoverLBI-39123EERICSSONZEricsson Inc.Private Radio SystemsMountain View RoadLynchburg, Virginia 245021-800-528-7711 (Outside USA, 804-592-7711) Printed in U.S.A.PRODUCTION CHANGESChanges in the equipment to improve performance or to simplifycircuits are identified by a "Revision Letter" which is stamped after themodel number of the unit. The revision stamped on the unit includes allprevious revisions. Refer to the Parts List for the descriptions of partsaffected by these revisions.REV. B - RECEIVER IF MODULE 19D902494G7To improve production of Group 7 boards. New schematic (193D1065).REV. A - RECEIVER IF MODULE 19D902494G11To ensure correct operation, U7 (19A701789P4) was replaced.REV. B - RECEIVER IF MODULE 19D902494G11To increase margins on squelch threshold sensitivity and 12 dBSINAD in 12.5 kHz mode. C86 was 0.01 µF (19A702052P14),R6 was 50 ohms (19B800607P510), R97 was 39 ohms(19B801251P390) and R98 and R99 were 150 ohms(19B801251P151). Added L6 (19A705430P24).

CIRCUIT ANALYSISINPUT AMPLIFIER NETWORKThe input amplifier, consisting of Q2 and T1, provides a50 ohm load for the receiver RF module. Capacitor C1 provides AC coupling and a DC block onthe input line (J1). This DC block protects the module in theevent of a failure in a preceding module. C1 and L9 are series-resonant at 21.4 MHz and provide alow-impedance path from J1 to amplifier Q2. C89 and L8are parallel-resonant at 21.4 MHz and provide a path to the50-ohm lead, R105, for mixer products other than 21.4MHz. CRYSTAL FILTERS, IF AMPLIFIERSY1, Y2, U1, and associated circuitry provide IF filteringand amplification at 21.4 MHz. Filters Y1 and Y2 are both 4-pole bandpass filters with a center frequency of 21.4 MHzand a bandwidth of ±6.5 kHz. Amplifier UI is an integrated-circuit amplifier. U1 provides 30 dB of gain. The amplifierand filters have terminal impedances of 50 ohms. In-circuitgain measurements can be made using a high impedanceprobe.Inductors L3, L5 and associated resistors and capacitorsprovide power supply decoupling. R3 provides a path to theinput of the Fault Detector circuit. This input enables theFault Detector circuit to monitor the DC voltage of U1.The RF level detector consists of transistor Q1 alongwith associated resistors and capacitors. This detector playsno role in the normal operation of the IF Module, but aids inunit testing and module troubleshooting.OSCILLATOR/MIXER/DETECTORIntegrated circuit U3 provides several functions includ-ing 2nd mixer, if amplifier and limiter, and quadrature detec-tor.The 20.945 MHz crystal oscillator provides local oscilla-tor injection to the mixer in U3. This mixer converts the 21.4MHz IF signal to 455 kHz. C20 and C21 are oscillator feed-back capacitors and have been chosen to provide the propercapacitance for crystal Y3. The proper oscillator output levelis difficult to measure directly without affecting the oscilla-tion. A preferable measurement is at TP3 which should readabout 10 mV pk. (Measured using a 10 megohm 11 pF oscil-loscope probe.)The mixer is internally connected to the crystal oscillator.Pins 1 and 20 of U3 are the mixer input and output respec-tively. Typical mixer conversion loss is about 2 dB. In the 12.5 kHz mode, the output of the mixer drives theIF amplifier via analog switch U11-2, filter FL1 and analogswitch U11-3. In the 25 kHz mode, the mixer output isrouted through analog switch U11-1 and C85 to the IF am-plifier. The analog switches are controlled by the signal atpoint ’A’; high for 25 kHz, low for 12.5 kHz.The IF amplifier output drives the limiter via the 6-poleceramic filter FL2.A received-signal-strength indicator (RSSI) is providedat U3 Pin 7. This indicator signal is generated within thelimiter circuitry and provides an output current proportionalto the logarithm of the input signal strength. This current de-velops a voltage across R18. The voltage varies from about 1Vdc for noise input, to about 1.4 Vdc for a 12 dB SINADsignal, to a maximum of about 4.8 Vdc for a high signallevel (70 dB stronger than that required for 12 dB SINAD).The quadrature detector provides a demodulated audiofrequency output. The input to the detector is internally con-nected to the limiter and is not externally available. The out-put of the detector is U3 pin 9. C28 provides low-passfiltering to remove 455 kHz feedthrough. Ceramic resonatorY4 provides the frequency selective component needed forFM demodulation. Y4 replaces the typical LC resonant cir-cuit found in most quadrature detectors. In contrast to thetypical LC network, Y4 requires no adjustment.The DC supply to U3 is provided through voltage drop-ping resistor R11 to U3 pin 6. R12 provides a path to the in-put of the Fault Detection circuit. This enables the FaultDetector to monitor the DC voltage on U3.AUDIO AMPLIFIEROperational amplifier U6.3 provides audio frequencyamplification. Its gain is set by its associated resistors, in-cluding variable resistor VR1. VR1 allows for adjusting theAF output level to 1 Vrms with a standard input signal to themodule (1 kHz AF, 3 kHz peak deviation). In the 12.5 kHzmode, the demodulated audio is at a lower level than in the25 kHz mode. The gain of amplifier U6.3 is, therefore, in-creased to give the same 1V rms output with a standard inputsignal to the module of 1.5 kHz deviation. This is done bytransistor switch Q6 connecting R1 across R40. U6.2 isused as a voltage regulator to provide 4 Vdc for biasing theoperational amplifier.Copyright© November 1994, Ericsson GE Mobile Communications Inc.TABLE 1 - GENERAL SPECIFICATIONSITEM SPECIFICATIONI.F. frequencyInput Impedancel2 dB SINADAdj. CH SELImage3rd order Intercept PtVariation of Sensitivity with Signal Frequency2nd I.F. frequency2nd L.O. frequencyAF output (J2 pin 31C)AF output impedanceAF distortionAF response10 Hz300 Hz1000 Hz3 kHzHum & NoiseRSSI output (J2 pin 20C)RSSI time constantSQ Threshold SensitivitySQ Maximum SensitivitySQ ClippingSQ AttackSQ CloseSQ output (J2 pin 26C)Fault output (J2 pin IIC)DC Supply21.4 MHz50 ohm-120 dBm (25 kHz); -119 dBm (12.5 kHz)-90 dB (25 kHz); -80 dB (12.5 kHz)-100 dB23 dBm (25 kHz); 11 dBm *(12.5 kHz) *@ 50 kHz offset2 kHz (25 kHz); 1 kHz (12.5 kHz)455 kHz20.945 MHz1 Vrms adjustable (with standard input signal)1k ohm5% (25 kHz); 5% (12.5 kHz)-3 dB±1 dB0 dB reference±1 dB-55 dB (25 kHz); -50 dB (12.5 kHz)0.7 to 2.7 Vdc prop to log (sig level)5 ms-123 dBm (25 kHz); -122 dBm (12.5 kHz)-110 dBm (25 kHz); -109 dBm (12.5 kHz)3 kHz150 ms250 ms5V logic (low = squelched)5V logic (low = fault)13.8V, 150 mA max.; 12.0V, 18 mA max.This manual is published by Ericsson Inc., without any warranty. Improvements and changes to this manual necessitated by typographical errors,inaccuracies of current information, or improvements to programs and/or equipment, may be made by Ericsson Inc., at any time and without no-tice. Such changes will be incorporated into new editions of this manual. No part of this manual may be reproduced or transmitted in any form orby any means, electronic or mechanical, including photocopying and recording, for any purpose, without the express written permission ofEricsson Inc.LBI-39123E1

SQUELCHBuffer AmplifierIntegrated circuit U6.4 is configured as a unity gain bufferamplifier. It provides a high input impedance to minimize load-ing of the previous circuits.Bandpass FilterThe audio frequency bandpass filter consists of U7.1 and itsassociated circuitry. The purpose of this filter is to reject allvoice frequencies and allow only demodulated noise to pass.The functioning of the squelch circuit depends upon the pres-ence or absence of this noise. (When a signal is being received,i.e. the receiver is quiet, the squelch circuit senses the absenceof noise and unsquelches the radio.)Noise DetectorU7.2 along with associated components act as a noise de-tector. The rectified output of U7.2 charges C11/C44 to anearly constant DC voltage.DC AmplifierU7.3 is configured as a basic amplifier with a gain of 3.Schmitt TriggerU7.4 is configured as an amplifier with positive feedback.This arrangement provides hysteresis in the output versus inputcharacteristic. This eliminates the possibility of the squelch cir-cuit repeatedly cutting in and out when the input signal is neara threshold. R56 and R57 act as a voltage divider to provide a 5volt logic level output. (Logic High = unsquelched)FAULT DETECTORU4 and U5 are voltage comparators. These are configuredinto four "window detectors" which sense the presence of volt-ages within specified ranges (windows).The four window detector circuits are U4.1 & U4.2, U4.4& U4.3, U5.1 & U5.2, and U5.4 & U5.3. These monitor DCoperating voltages on U6.2, U1, Q2, and U3 respectively. R29and R30 comprise a voltage divider to provide a 5 volt logiclevel output. A fault is indicated when the output drops to zero.Diode D1 and transistor Q3 monitor the output of the 8Vregulator. DI is a 8.2 volt breakdown diode. If the regulatoroutput voltage should rise above 8.9 V (8.2 + 0.7 base-emitterdrop) Q1will turn on and a fault will be indicated.Transistors Q4 and Q5 are drivers for the front panel LEDCRI. These are powered from the +13.8 Vdc line before the 8Vregulator. Therefore, if the regulator opens, a fault will still beindicated.VOLTAGE REGULATORU8 is a monolithic integrated-circuit voltage regulator pro-viding 8 Vdc. This powers all circuitry in the module with theexception of Q2, the front panel LED and its drivers.ADDRESS DECODERThe address decoder consists of U2, an 8-stage shift regis-ter, and U9, a BCD-to-decimal decoder. When A2, A1 and A0are ’1’, ’1’, ’0’, respectively and the ENABLE line is high, Q7on U9 goes high. This enables data input to U2 to propagatethrough it, controlled by the clock pulses on U2-3. When theENABLE signal goes low, U9-4 goes low, and the shift-registeroutputs are latched. Q1 on U2 is then high for the 12.5 kHzmode, and low for the 25 kHz mode.MAINTENANCERECOMMENDED TEST EQUIPMENTThe following test equipment is required to test the IFModule.1. FM Signal Generator; HP 8640B, HP 8657A, orequivalent2. AF Generator or Function Generator3. Audio Analyzer; HP 8903B, HP 339A, or equivalent4. Oscilloscope5. Frequency Counter; Racal-Dana 9919 or equivalent6. DC Meter for troubleshooting7. Power Supply; 13.8 Vdc @ 150 mA8 Power Supply; 12 Vdc @20 mAALIGNMENT PROCEDURE1. Apply 13.8 Vdc and 12 Vdc supplies to module.2. Verify 13.8 V DC current consumption is between 90and 150 mA, and 12 Vdc current is between 12 and 18mA.3. Verify fault output is 0 to 0.5 Vdc and front panel LEDis off.21.4 MHz IF MODULE - BLOCK DIAGRAMLBI-39123E2

4. Apply a standard input signal to the module input. (-60dBm, 21.4 MHz signal modulated with 1 kHz AF, 3kHz peak deviation)5. Monitor TP5 with a high-impedance probe connected tothe frequency counter. Adjust L10 for a reading of 455kHz ± 100 Hz.6. Set VRI for 1 Vrms ±3% at module output (pin 31C on96 pin connector J2).TROUBLESHOOTINGWhen troubleshooting the module, it is most convenient ifthe standard test fixture is used. The following conditions arewith the module in the 25 kHz mode. This can be set up usinga PC with the necessary software connected to the test fixture.Alternatively, a wire link can be soldered between holes H1and H2 on the PC board.IF amplifier Q2 has a nominal 8 dB gain. U1 has a nominalgain of 30 dB. The mixer has about 2 dB loss with proper LOinjection. The proper crystal oscillator level is 10 mV pk meas-ured at TP3.The following four test points are provided on the PWB foradditional test capability:TP1: 60 mV pk @ 21.4 MHz with -30 dBm input signalTP3: 10 mV pk @ 20.945 MHz independent of input sig-nalTP4: 20 mV pk @ 455 kHz with -60 dBm input signalTP5: 750 mV pk @ 455 kHz with -60 dbm input signalAll RF voltages measured with 10 Megohm, 11 pF probe. ASSEMBLY DIAGRAM TROUBLE SHOOTING GUIDESYMPTOM CHECK(CORRECT READING SHOWN) INCORRECT READINGINDICATES DEFECTIVECOMPONENTFault indicator on Check DC voltages +8V at U8 Pin 1 +4v at U6 Pin 7 5.5V at U1 output pin 6V at U3 Pin 5If DC voltages not correct U8 or associated components U6 or associated components U1 or associated components U3 or associated componentsIf DC voltages correct U4, U5, U6, DI, Q3, Q4, Q5No audio - no noise With no signal applied to module IF input Check for AF noise @ C29 ; 200mV Check for AF noise @ U6 Pin 14:1 VU3 or associated componentsU6 or associated componentsNoise only - nodemodulated audio Check crystal oscillator: TP3 10 mVpk 20.945 MHzApply-30 dBm 21.4 MHz input, check TPl 60 mVpkApply-60 dBm 21.4 MHz input, check TP4 20 mVpkU3, Y3 or associated componentsQ2, Y1, U1 or associated componentsU3, FL1 or associated componentsPoor 12 dB SINAD Check crystal oscillator: TP3 10 mVpk 20.945 MHzApply-30 dBm 21.4 MHz input, check TP1 60 mVpkApply-60 dBm 21.4 MHz input, check TP4 20 mVpkU3, Y3 or associated componentsQ6, Y1, U1 or associated componentsU3, FL1 or associated componentsNo squelchfunction With squelch pot maximum, or with module AUDIO/SQUELCH/HI connected to SQUELCH/ARM inputand with no signal to module IF input:Check Presence of 1 Vpk noise at U6 Pin 14Check presence of 1 Vpk noise U7 at Pin 1Check DC voltage U7 at Pin 8: 7VCheck DC voltage U7 at Pin 14: 0.5VU6 or associated componentsU7 or associated components RECEIVER IF MODULE19D902783G7, G11(19D902783, Sh. 1, Rev. 3)LBI-39123E3

OUTLINE DIAGRAMRECEIVER IF MODULE (EARLIER VERSION)19D902494G7, G11(19D902494, Sh.3, Rev. 6)RECEIVER IF MODULE 19D902494G7 & G11(19D902494, Sh.4, Rev. 6)LBI-39123E4

SCHEMATIC DIAGRAMRECEIVER IF MODULE (EARLIER VERSION)19D902494G7, G11(188D5586, Sh. 1, Rev. 3)LBI-39123E5

SCHEMATIC DIAGRAMRECEIVER IF MODULE (EARLIER VERSION)19D902494G7, G11(188D5586, Sh. 2, Rev. 3)LBI-39123E6

SCHEMATIC DIAGRAMRECEIVER IF MODULE19D902494G7 & G11(193D1065, Sh. 1, Rev. 3)LBI-39123E7

SCHEMATIC DIAGRAMRECEIVER IF MODULE19D902494G7 & G11(193D1065, Sh. 2, Rev. 3)LBI-39123E8

SCHEMATIC DIAGRAMRECEIVER IF MODULE19D902494G7 & G11(193D1065, Sh. 3, Rev. 3)LBI-39123E9

IC DATAU1344A3740P1Silicon Bipolar ICU319A705535P3FM ReceiverU4 & U519A704125P1kQuad ComparatorU6 & U719A701789P4Quad Op-AmpU819A704971P10Voltage RegulatorU11RYT3066018/CBilateral SwitchLBI-39123E10

LBI-39129BTABLE OF CONTENTSPageDESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Front CoverSPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1CIRCUIT ANALYSISPRESELECTOR FILTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1PREAMPLIFIER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1IMAGE REJECTION FILTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1INJECTION AMPLIFIER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1INJECTION FILTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1DOUBLE BALANCE MIXER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1FAULT DETECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1MAINTENANCETEST PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2ALIGNMENT PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2TROUBLESHOOTING PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1TABLE 2 - RETUNING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3PRODUCTION CHANGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3OUTLINE DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4ASSEMBLY DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5SCHEMATIC DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6MAINTENANCE MANUAL FORRECEIVER FRONT END MODULE19D902782G6, G8, G9, G10, G11, G12DESCRIPTIONThe Receiver Front End (RXFE) Module amplifiesand converts the RF signal to the first IF at 21.4 MHz.This is a down conversion process using low side (G9,G10) or high side (G6, G8, G11, G12) injection. TheRXFE module is powered by a regulated 12 volts. TheRXFE printed wiring board contains the following func-tional circuits:•Preselector Filter•Preamplifier•Image Rejection Filter•Injection Amplifier•Injection Filter•Double Balanced Mixer•Fault DetectorAll but the Fault Detector circuit in the RXFEmodule have 50 ohm impedance terminations.ERICSSONZEricsson Inc.Private Radio SystemsMountain View RoadLynchburg, Virginia 245021-800-528-7711 (Outside USA, 804-528-7711) Printed in U.S.A.

CIRCUIT ANALYSISPRESELECTOR FILTERThe received RF signal (J2) is routed through the Prese-lector Filter (L1 through L5). This filter provides front endselectivity and attenuates the potential spurious signals of thefirst conversion. Typically, the filter has an insertion loss of 3dB and an operational bandwidth of 2 MHz. The filter is atunable, five-pole helical bandpass filter.PREAMPLIFIERThe output from the Preselector is coupled through animpedance matching network consisting of C1, C2 and L6 tothe base of Preamplifier Q1. The Preamplifier stage is suppliedby the regulated +12 Vdc line (VCC1) and draws about 80 mA.It has a low noise figure and high Third Order Intercept point.Transistor Q2 provides Q1 with a constant current source. Thebias on Q1 is monitored by the Fault Detector circuit via R17.Capacitors C20 and C21 prevent any RF from entering the faultcircuit. The preamplifier output signal is coupled to the ImageRejection Filter via an impedance matching network consistingof C4, C11, L8, L15, R5 and R6.IMAGE REJECTION FILTERFollowing the Preamplifier is the Image Rejection Filter.The Image Rejection Filter is a fixed tuned helical bandpassfilter. The Filter has an insertion loss of about 2 dB.INJECTION AMPLIFIERThe local oscillator input (J3) from the Receiver Synthe-sizer is coupled to monolithic amplifier U2, then to the base ofQ8. The Injection Amplifier, consisting of U2, Q8, and associ-ated circuitry, is capable of amplifying the injection signal toapproximately 18 to 22 dBm. The amplifier is powered by theregulated +12 Vdc line (VCC1). Transistor Q7 provides Q8with a constant current source. The bias on U2 and Q8 ismonitored by the Fault Detector circuit via R21 and R31,respectively. Capacitors C22, C23 and C26 prevent RF fromentering the fault circuit. The Injection Amplifier outputsignal is coupled to the Injection Filter via an impedancematching network consisting of C8, L13, and resistors R15and R16.INJECTION FILTERFollowing the Injection Amplifier is the Injection Filter.The injection filter is a fixed, tuned helical bandpass filter.It is used to attenuate harmonics of the Injection Amplifier.The filter has an insertion loss of about 2 dB.DOUBLE BALANCE MIXERThe Double Balance Mixer (DBM) is a broadbandmixer. It converts an RF signal to the 21.4 MHz first conver-sion IF frequency. The mixer uses low side (G9, G10) or highside (G6, G8, G11, G12) injection driven by a local oscillatorsignal. The mixer conversion loss is typically about 7 dB.The IF output signal is then routed through a diplexer circuitto the output connector (J4).FAULT DETECTORThe Fault Detector circuit monitors the operation of thepreamplifier and injection amplifier devices. Operationalamplifiers U1.1 and U1.2 compare the bias on the Preampli-fier Q1 to preset levels, while U1.3 and U1.4 compare thebias levels on Injection Amplifiers U2 and Q8.When the bias for Q1, U2, and Q8 is within the presetwindow limits, the output from the comparators is a logichigh level. This high level signal is sent to the StationController on the FLAG 0 line.If the biasing for the amplifiers is not within the properoperating range, the fault detector circuit will pull the FLAG0 line low.Copyright© November 1994, Ericsson GE Mobile Communications, Inc.Table 1 - General SpecificationsITEM SPECIFICATIONFREQUENCY RANGE 380 - 400 MHz (G8)403 - 430 MHz (G11)470 - 492 MHz (G9)492 - 512 MHz (G10)403 - 425 MHz (G6)370 - 390 MHz (G12)IF FREQUENCY 21.4 MHz3 dB BANDWIDTH >3 MHzIMPEDANCE 50 ohms at RF, LO, and IF PortsCONVERSION LOSS -1.5 ± 1.5dBNOISE FIGURE (NF) <7.5 dBTHIRD ORDER INTERCEPT POINT >20 dBm (G9, G10)>16 dBm (G6, G8, G11, G12)IMAGE REJECTION >100dBINJECTION POWER -1.5 ± 1.5dBTEMPERATURE RANGE -30°C TO +60°CSUPPLY VOLTAGE 12.0 VdcSUPPLY CURRENT 200 mA typical Figure 1 - Block DiagramLBI-39129B1

MAINTENANCETEST PROCEDUREFollowing is a test procedure of the module to verifyproper Conversion Gain :1. Supply 12 Vdc to pin 15A, B, C. (1C is ground.)2. Inject the desired RF Frequency into RF IN at a levelof -10 dBm.3. Inject the desired local oscillator frequency into LOIN at a level of 0 dBm [LO frequency = RF frequency- 21.4 MHz (for groups G9, G10), or, LO frequency= RF frequency + 21.4 MHz (for groups G6, G8,G11, G12)].4. Measure the IF OUT power at 21.4 MHz, the ratio ofRF IN to IF OUT should be -1.5 ±1.5 dB.5. Measure the current drawn by the RXFE module.Typical current drain is 180 to 230 mA.ALIGNMENT PROCEDUREAlignment for the Receiver Front End module consistsof tuning the five-pole Preselector Filter only. The ImageRejection Filter and LO injection filter are not to be tuned.Normally, the RXFE should only need the fine-tuning pro-cedure. For a major receiver frequency change, the RXFEshould be adjusted using the major-retuning procedure.For Fine-Tuning1. Supply 12 Vdc to pin 15A, B, C. (1C is ground.)2. Inject the desired RF Frequency into RF IN (J2) at alevel of -10 dBm.3. Inject the desired local oscillator frequency into LOIN (J3) at a level of 0 dBm [LO frequency = RFfrequency - 21.4 MHz (for groups G9, G10), or, LOfrequency = RF frequency + 21.4 MHz (for groupsG6, G8, G11, G12)].4. Detect IF signal at 21.4 MHz. Slightly adjust L1 toL5 to get maximum power (don’t adjust more than1/4 turn). If an RF Voltmeter is used, connect a LowPass Filter (LPF)to the IF OUT (J4) to attenuate highfrequency components. The corner of the LPF shouldbe set for 40 MHz.5. Repeat Test Procedure steps to verify conversiongain.For Major RetuningThe best way to do a major retuning of the RXFE is withswept frequency tuning. The swept frequency tuning can bedone using a Spectrum Analyzer and Tracking Generator.With proper Injection level the frequency response of thePreselector Filter can be seen by viewing the RF to IF portfeedthrough on the spectrum analyzer. This feedthrough istypically 35 dB down from the input level at the RF port. Usethe following procedure for swept frequency tuning:1. Supply 12 Vdc to pin 15A, B, C. (1C is ground.)2. Inject the Tracking generator output at 0 dBm intothe RF IN connector, (J2).3. Inject local oscillator power at 0 dBm into the LO INconnector, (J3) [LO frequency = RF frequency - 21.4MHz (for groups G9, G10), or, LO frequency = RFfrequency + 21.4 MHz (for groups G6, G8, G11,G12)].4. Preset the height of slugs with respect to the top offive-pole cavity as follows (Table 2):5. Center the spectrum analyzer at the desired frequencyand set the reference at about -30 dBm. Adjust L1 toL5 for best possible response.SYMPTOM AREAS TO CHECK READING (TYP.)LOW CONVERSION GAIN Check Vcc 12 VPreselector Loss 3 dBPreamplifier Gain 11 dBImage Rej. Filter Loss 2 dB1st Mixer Conversion Loss 7 dBFAULT INDICATOR LOW Check Vc of Q1 9 TO 10VCheck Vc of U2 5 TO 6 VCheck Vc of Q8 9 TO 10 VIF FREQUENCY OFF Check L.O. FREQUENCY L.O. frequency=RF frequency - 21.4 MHz (G9,G10) + 21.4 MHz (G6, G8, G11, G12)LOW L.O. POWER* Injection Amplifier Gain approx 20 dB GainInjection Filter Loss 2 dB*NOTE: For troubleshooting the gain or loss, the RXFE needs to be under the normal operating condition:•12 Vdc supply.•Inject L.O. power at a level of 0 dBm into LO IN (J3), [LO freq. = RF freq. - 21.4 MHz (G9, G10) or, LO frequency = RF frequency + 21.4 MHz (G6, G8, G11, G12)].•Inject the desired RF signal at a level of -10 dBm into RF IN (J2).•Terminate the IF OUT (J4) with a good 50 ohm impedance.•Use a Spectrum Analyzer and 50 ohm probe (with good RF grounding) to probe at the input and output ofeach stage to check its gain or loss (see schematic diagram).TROUBLESHOOTING GUIDEG6 & G11 HEIGHT (in inches)Frequency (MHz) L1 L2 L3 L4 L5403 12/64 10/64 12/64 13/64 12/64408 13/64 13/64 14/64 14/64 13/64413 14/64 14/64 14/64 15/64 14/64418 16/64 16/64 15/64 16/64 15/64423 17/64 17/64 16/64 18/64 16/64Table 2G9 HEIGHT (in inches)Frequency(MHz) L1 L2 L3 L4 L5470 12/64 12/64 12/64 12/64 12/64474 13/64 13/64 13/64 13/64 13/64478 14/64 14/64 14/64 14/64 14/64482 15/64 15/64 15/64 15/64 15/64486 16/64 16/64 16/64 16/64 16/64490 17/64 17/64 17/64 17/64 17/64492 18/64 18/64 18/64 18/64 18/64G10 HEIGHT (in inches)Frequency(MHz) L1 L2 L3 L4 L5492 12/64 10/64 10/64 10/64 8/64497 12/64 10/64 12/64 12/64 9/64502 14/64 12/64 13/64 14/64 10/64507 15/64 15/64 16/64 16/64 12/64512 17/64 16/64 17/64 17/64 14/64G8, G12 HEIGHT (in inches)Frequency(MHz) L1 L2 L3 L4 L5380 16/64 16/64 16/64 16/64 16/64385 17/64 17/64 17/64 17/64 17/64390 18/64 18/64 18/64 18/64 18/64395 19/64 19/64 19/64 19/64 19/64400 20/64 20/64 20/64 20/64 20/64370 14/64 14/64 14/64 14/64 14/64375 15/64 15/64 15/64 15/64 15/64LBI-39129B2

OUTLINE DIAGRAMU119A704125P1Quad Operational Amplifier(19D902490, Sh. 7, Rev. 5)RECEIVER FRONT END BOARD19D902490G6, G8 - G12LBI-39129B4

ASSEMBLY DIAGRAMRECEIVER FRONT END MODULE19D902782G6, G8 - G12(19D902782 Sh.2 Rev.3)LBI-39129B5

SCHEMATIC DIAGRAMRECEIVER FRONT END MODULE19D902782G6, G8-G12(188D5789 Sh.1, Rev. 6A)LBI-39129B6

SCHEMATIC DIAGRAMRECEIVER FRONT END MODULE19D902782G6, G8 - G12(188D5789 Sh.2, Rev. 6A)LBI-39129B7

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