LBI-38865A Maintenance Manual Monogram Series UHF MOBILE RADIO MODEL MGM 450 ericssonz
LBI-38865 NOTICE! This manual covers Ericsson and General Electric products manufactured and sold by Ericsson Inc. NOTE 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 the manufacturer could void the user’s authority to operate the equipment in addition to the manufacturer’s warranty.
MONOGRAM SERIES LBI-38865 TABLE OF CONTENTS TABLE OF CONTENTS SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 GENERAL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 RECEIVER (PER EIA RS-204-C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MONOGRAM SERIES LBI-38865 TABLE OF CONTENTS ELECTRICAL PARTS LIST. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 PRINTED CIRCUIT BOARDS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 TOP VIEW 406136-F ISSUE: H / RF BOARD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32.
MONOGRAM SERIES LBI-38865 SPECIFICATIONS SPECIFICATIONS GENERAL Frequency Range A Band 400-440 MHz C Band 450-470 MHz E Band 470-512 MHz Channels 16 maximum Channel Spacing 25 kHz Programmable (In 6.25 kHz Steps) Input Voltage 13.8 VDC Negative Ground Current Drain Standby 0.15 Amp Receive 0.5 Amp Transmit 8 Amp Temperature Range -30° to + 60° C Dimensions 2 x 6 x 8.25 inches (51 x 152 x 210 mm) Weight 4 lbs., 3 oz. (1.9kg) With Mic.
MONOGRAM SERIES LBI-38865 SPECIFICATIONS RECEIVER (PER EIA RS-204-C) RF Input Impedance 50 Ohms Nominal Sensitivity: (EIA 12 dB SINAD) 0.35 uV 20 dB Quieting 0.50 uV Squelch Sensitivity 0.20 uV Threshold Selectivity -80 dB Intermodulation -70 dB Modulation Acceptance Bandwidth ±7.5 kHz Spurious and Image -70 dB Audio Power Output 5 W (@10% Dist. into 40 W Load) Frequency Stability ± 0.
MONOGRAM SERIES LBI-38865 SPECIFICATIONS TRANSMITTER (PER EIA RS-152-C) RF Power Output 40 Watts (adjustable) RF Output Impedance 50 Ohms Spurious and Harmonics -70 dBc Modulation 16KOF3E FM Hum and Noise -45 dB Nominal Audio Distortion < 3 % @ 1000Hz Frequency Stability 0.0005% Operational Bandwidth 20 mHz ( 3dB degradation at band limits) UHF PROGRAMMING CHART TRANSMIT Frequency Spread Band Width Factory Programmed Freq.
MONOGRAM SERIES LBI-38865 SPECIFICATIONS OPTIONS AND ACCESSORIES CONTROL STATION OPTIONS: Desk Microphone MGMC5H External Speaker MGZM7C Power Supply MGPS5V NOT SHOWN: Antenna - MGAN1A Relay Kit - MGSU1C Noise Suppression Kit - MGPD1A Page-4Nov.
MONOGRAM SERIES LBI-38865 UNPACKING UNPACKING Check the carton and packing material carefully for the following items: 1. Transceiver Unit 2. Microphone 3. DC power cord 4. Mobile Mounting Bracket 5. Assembly Hardware 6. Operating Guide Styrofoam not used Inner Packing is now cardboard tray box. Figure 1 - Unpacking Diagram Page-5Nov.
MONOGRAM SERIES LBI-38865 INTRODUCTION INTRODUCTION The Conventional Monogram Series Radio is a rugged two-way FM mobile radio which operated in the 400-440 MHz, 450-470 MHz or the 470-512 MHz band split. The Monogram is a synthesized radio utilizing microcomputer technology to provide reliable high quality simplex two-way mobile communications. Its transmitter output power level is 40 watts over the wide bandwidth, with an allowable 10 MHz maximum receive channel separation.
MONOGRAM SERIES LBI-38865 DESCRIPTION OF CONTROLS DESCRIPTION OF CONTROLS FRONT PANEL CONTROLS 1. Squelch Control: The squelch control will silence the receiver when no signal is being received. 2. ON/OF/VOLUME Control: This is the main power switch and volume control. 3. Monitor Button (2): This button performs three functions: a. Disables tone or digital squelch options when in receive mode. b. Returns to normal radio operation from the programming mode. c. Controls display intensity. 4.
MONOGRAM SERIES LBI-38865 DESCRIPTION OF CONTROLS BACK PANEL CONNECTORS 1. External Speaker Connector: This 3.5mm diameter jack is provided for a 4 ohm external speaker. The internal speaker is silenced when the external speaker is connected. 2. Auxiliary Speaker Connector: This 3.5mm diameter jack is provided for an auxiliary speaker (Option MGSU1C Relay Kit is required). 3. Antenna Connector: An SO-239 type connector. The output load must be 50 ohms. 4. DC 13.8V Connector: Polarized plug for 13.
MONOGRAM SERIES LBI-38865 OPERATION OPERATION • NOTE: The following description briefly outlines the operation of your UHF synthesized mobile radio. Consult the operators manual for a complete description of all the modes of operation for which the radio is capable. RADIO ON/OFF, POWER UP 1. Turn the radio on by turning the VOLUME control one-half turn clockwise. After 4000 appears in the display and the power up alert tone is generated, the display will change to the #1 priority channel.
MONOGRAM SERIES LBI-38865 OPERATION DIGITAL CHANNEL GUARD Channel Guard provides a means of restricting calls to specific radios through the use of a continuous tone coded squelch system (CTCSS), or a multi-code digital squelch system (DCG). tone frequencies range from 67Hz to 250.3Hz. There are 83 standard programmable digital codes. The Channel Guard tone frequencies and codes are software programmable. Both tone frequencies and digital codes may be mixed on each channel.
MONOGRAM SERIES LBI-38865 CIRCUIT ANALYSIS CIRCUIT ANALYSIS RECEIVER RF Amplifier Incoming signals from the antenna jack are routed backwards through the transmitter lowpass filter in PIN diode switch D16. In receive mode, D16 conducts allowing a low impedance path through the diode to the receiver front end circuitry. The receiver RF amplifier section is comprised of two bandpass filter sections separated by an amplifier based around Q1.
MONOGRAM SERIES LBI-38865 CIRCUIT ANALYSIS Squelch The presence of an RF carrier is determined by noting the level of ultrasonic noise at the detector output (pin9) of IC2. When a carrier is present, the noise level drops. The audio at pin 9 of IC2 is filtered by a two-pole bandpass filter formed around L17, L18, C68 and C69. This filter passes audio at and near an audio frequency of 50 kHz. This frequency is high enough that voice audio and its harmonics will not cause improper squelch operation.
MONOGRAM SERIES LBI-38865 CIRCUIT ANALYSIS counter, a phase/frequency comparator and a frequency lock detector. The operation of this integrated circuit is controlled by the radio’s microprocessor through a serial data line. Reference Oscillator Crystal X2, varactor D122, a thermistor/resistor network and the oscillator stage of IC118 form a temperature compensated 12.8 MHz oscillator. This frequency is divided by 2048 to generate the 6.25 kHz frequency for the PLL frequency synthesizer.
MONOGRAM SERIES LBI-38865 PREVENTIVE MAINTENANCE PREVENTIVE MAINTENANCE To ensure high operating efficiency and to prevent mechanical and electrical failures from interrupting system operations, routing checks should be made of all mechanical and electrical parts at regular intervals. Preventive maintenance should include the following checks: CONNECTIONS Ground connections to the voltage source should be periodically checked for tightness.
MONOGRAM SERIES LBI-38865 DISASSEMBLY DISASSEMBLY TOP AND BOTTOM COVERS There are no screws used to secure the top and bottom covers. Both top and bottom covers are removed with a flat blade screwdriver or similar tool. On each side of the radio there are two small slots (one at the top and one at the bottom). Insert the screwdriver into the slot and gently pry the lip of the cover out from the radio. without removing the screwdriver from the slot and in the same motion, pry the cover up.
MONOGRAM SERIES LBI-38865 DISASSEMBLY DIGITAL BOARD 1. Remove the (6) M3 x 18 machine screws that secure the top panel shield to the chassis. 2. Unplug and remove the Auxiliary Relay PCB at PL5. 3. Remove the (6) machine screws (3 on top and 3 on bottom) that secure the front panel to the chassis. • The following steps detail the removal of the RF shield which is necessary before continuing with the removal of the digital board. 4.
MONOGRAM SERIES LBI-38865 PROGRAMMING INSTRUCTION PROGRAMMING INSTRUCTION The UHF synthesized mobile radio is equipped with a personality EEPROM. All customer information such as the customer frequencies, customer tones and customer options are stored in the EEPROM. The EEPROM contains all information to tailor the operation of the radio to the user’s requirements. The EEPROM is programmed by using an IBM compatible personal computer with MSDOS, Programming Cable TQ-3376 and Programming software TQ-3375.
MONOGRAM SERIES LBI-38865 TEST EQUIPMENT SETUP TEST EQUIPMENT SETUP * * * = OPTIONAL TEST EQ. Page-18Nov.
MONOGRAM SERIES LBI-38865 ALIGNMENT PROCEDURE ALIGNMENT PROCEDURE SUGGESTED TEST EQUIPMENT • WARNING: Any repairs or adjustments should be made under the supervision of a certified technician. The following equipment, or its equivalent, is required for proper alignment of the UHF synthesized mobile radio: 1. Termaline watt meter or Through-line watt meter with termination into 50 ohm dummy load. 2. AC/DC VOM with a minimum of 1 Megohm input impedance. 3. SINAD Meter. 4. FM Communications Monitor. 5.
MONOGRAM SERIES LBI-38865 ALIGNMENT PROCEDURE 4. The middle RX/TX frequencies should be halfway between the lowest and the highest frequencies. • NOTE: There should be 4 channels programmed with a total of 3 different frequencies. 5. The highest transmit frequency can typically be only 10 MHz above the lowest receiver frequency. PLLALIGNMENT 1. Connect an RF dummy load or power attenuator (50 watt minimum rating) to the antenna receptacle. 2.
MONOGRAM SERIES LBI-38865 ALIGNMENT PROCEDURE • WARNING: To prevent damage to the radio, avoid keying the radio for periods longer than 1 minute. Allow a 5 minute cool down period after keying the radio for 1 minute. 7. Check the power output at the lowest, middle and highest transmit channels and adjust RV2 if necessary, to maintain 40 watts at all frequencies. 8. Press PTT and adjust TC11 for the correct frequency. DCS Modulation Balance Adjustment 1.
MONOGRAM SERIES LBI-38865 ALIGNMENT PROCEDURE Modulation Deviation Adjustment 1. Connect an RF deviation meter to the radio through a power attenuator. 2. Set the CHANNEL selector to a transmit channel which has a DCS code pre-programmed (should be a mid-frequency channel). 3. Press the PTT switch. 4. Adjust RV3 for proper deviation, typically 750Hz. Release the PTT switch. 5. Set the CHANNEL selector to a transmit channel which has a low-frequency CTCSS tone (67.0Hz) pre-programmed. 6.
MONOGRAM SERIES LBI-38865 ALIGNMENT PROCEDURE Receiver Squelch Adjustment 1. Set the channel selector for the mid frequency receive channel. 2. Connect an RF signal generator or communications service monitor to the antenna receptacle. The modulation should be set fot ±3 kHz FM modulation of a 1kHz tone. The RF output level should be at a minimum. 3. Adjust the SQUELCH control to the threshold point (the point where the speaker audio disappears). 4.
MONOGRAM SERIES LBI-38865 RF BOARD ALIGNMENT AND TEST POINTS RF BOARD ALIGNMENT AND TEST POINTS Page-24Nov.
MONOGRAM SERIES LBI-38865 DIGITAL BOARD ALIGNMENT AND TEST POINTS DIGITAL BOARD ALIGNMENT AND TEST POINTS Page-25Nov.
MONOGRAM SERIES LBI-38865 PERFORMANCE TEST PERFORMANCE TEST TRANSMITTER PERFORMANCE TEST Power Output 1. Set the power supply voltage to 13.8 VDC (measured at the radio during transmit). 2. Connect an RF watt meter and dummy load to the antenna receptacle. 3. Press the PTT switch. 4. Verify that the output is at least 40 watts. 5. Reduce the power supply voltage to 11 volts. 6. Verify that the output is at least 15 watts. 7. Release the PTT switch. Audio Response 1.
MONOGRAM SERIES LBI-38865 PERFORMANCE TEST Spectrum Test 1. Connect a spectrum analyzer to a sampled RF output of the radio. 2. Press the PTT switch. Observe the output spectrum on the spectrum analyzer. 3. All spurious and harmonics should be at least 60 dB below the carrier level. 4. Release the PTT switch. RECEIVER PERFORMANCE TESTS SINAD Sensitivity 1. Connect the FM signal generator of communication service monitor to the antenna jack. 2. Connect a SINAD meter across the speaker leads. 3.
MONOGRAM SERIES LBI-38865 PERFORMANCE TEST Audio Output 1. Increase the RF signal generator or service monitor RF level to 1000 uV. 2. Connect a 4 ohm audio dummy load to the AUXILIARY speaker jack. 3. Connect a true RMS audio voltmeter (the audio distortion analyzer may include this function) to the speaker leads. 4.
MONOGRAM SERIES LBI-38865 COMPONENT REPLACEMENT COMPONENT REPLACEMENT SURFACE MOUNT COMPONENTS Surface mount components should always be replaced using a temperature controlled soldering system. The soldering tools may be either a temperature controlled soldering iron or a temperature controlled hot-air soldering station. A hot-air system is recommended for the removal of components on the multi-layered boards used in the UHF synthesized mobile radio.
MONOGRAM SERIES LBI-38865 COMPONENT REPLACEMENT SURFACE MOUNTED INTEGRATED CIRCUIT REPLACEMENT • CAUTION: Some chemicals may damage the internal and external plastic parts of the radio. Soldering and de-soldering techniques of the surface mounted IC’s are similar to the above outlined procedures for the surface mounted chip components. Use extreme care and observe static precautions when removing or replacing the defective (or suspect) IC’s.
ELECTRICAL PARTS LIST NOTE Only those items indicated by shading will be stocked by After Market Services. All other items are for reference only. When ordering parts for your Monogram Series radio, precede all part numbers with the prefix "R29/" Page-31Nov.
Page-31.
Page-31.
Page-31.
Page-31.
Page-31.
Page-31.
Page-31.
Page-31.
Page-31.
Page-31.
Page-31.
Page-31.
Page-31.
Page-31.
Page-31.
Page-31.
Page-31.
PRINTED CIRCUIT BOARD LAYOUT Page-32Nov.
MONOGRAM SERIES LBI-38865 TOP VIEW 406136-E RF BOARD TOP VIEW 406136-E RF BOARD Page -32.1Nov.
MONOGRAM SERIES LBI-38865 BOTTOM VIEW 406136-E RF BOARD BOTTOM VIEW 406136-E RF BOARD Page -32.2Nov.
MONOGRAM SERIES LBI-38865 TOP VIEW 406137-E DIGITAL BOARD TOP VIEW 406137-E DIGITAL BOARD Page -32.3Nov.
MONOGRAM SERIES LBI-38865 BOTTOM VIEW 406137-E DIGITAL BOARD BOTTOM VIEW 406137-E DIGITAL BOARD Page -32.4Nov.
MONOGRAM SERIES LBI-38865 MISC. PRINTED CIRCUIT BOARDS MISC. PRINTED CIRCUIT BOARDS DISPLAY BOARD TOP VIEW DISPLAY BOARD BOTTOM VIEW VOLUME BOARD TOP VIEW VOLUME BOARD BOTTOM VIEW Page -32.5Nov.
MONOGRAM SERIES LBI-38865 MISC. PRINTED CIRCUIT BOARDS MISC. PRINTED CIRCUIT BOARDS 406-969-F (DIG. PCB) BOTTOM 406-969-F (DIG. PCB) TOP 406-968-C (RF. PCB) TOP 406-968-C (RF. PCB) BOTTOM 406-973-A TOP 406-973-A BOTTOM Page -32.6Nov.
MONOGRAM SERIES LBI-38865 VOLTAGE CHARTS VOLTAGE CHARTS Page -32.7Nov.
MONOGRAM SERIES LBI-38865 VOLTAGE CHARTS VOLTAGE CHARTS Page -32.8Nov.
MONOGRAM SERIES LBI-38865 VOLTAGE CHARTS VOLTAGE CHARTS Page -32.9Nov.
MONOGRAM SERIES LBI-38865 VOLTAGE CHARTS Page -32.10Nov.
EXPLODED VIEW AND EXPLODED VIEW PARTS LIST NOTE Only those items indicated by shading will be stocked by After Market Services. All other items are for reference only. When ordering parts for your Monogram Series radio, precede all part numbers with the prefix "R29/" Page-33Nov.
MONOGRAM SERIES LBI-38865 Page -33.1Nov.
MONOGRAM SERIES LBI-38865 Page -33.2Nov.
MONOGRAM SERIES LBI-38865 Page -33.3Nov.
SCHEMATICS Ericsson Inc. Private Radio Systems Mountain View Road Lynchburg,Virginia 24502 1-800-528-7711 (Outside USA, 804-528-7711) Printed in U.S.A. Page-34Nov.
LBI-38865 RF BOARD R29/406136-E 34.
LBI-38865 DIGITAL BOARD R29/406137-E 34.
