LBI-38864B Maintenance Manual Monogram Series VHF MOBILE RADIO MODEL MGM 148 & 160 ericssonz
MONOGRAM SERIES LBI-38864B TABLE OF CONTENTS TABLE OF CONTENTS SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 Receiver (PER EIA RS-204-C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Transmitter (PER EIA RS-152-B). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MONOGRAM SERIES LBI-38864B TABLE OF CONTENTS Suggested Test Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Pre-Alignment Notes: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Programming For Alignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MONOGRAM SERIES LBI-38864B SPECIFICATIONS SPECIFICATIONS GENERAL Frequency Range VHF Low Band 136-150 MHz VHF Mid Band 148-165 MHz VHF High Band 160-174 MHz Channel Capability 16 max Channel Spacing 25 or 30 kHz Input Voltage 13.8 VDC negative ground Current Drain Standby 0.4 Amps (max) Receive 0.8 Amps (max) Transmit 9.5 Amps (max) Temperature Range -30° to +60° C Dimensions 2 x 6 x 8-1/4 in (51 x 152 x 210 mm) Weight 4 lbs, 3 oz (1.
MONOGRAM SERIES LBI-38864B SPECIFICATIONS RECEIVER (PER EIA RS-204-C) RF Input Impedance 50 ohms nominal Sensitivity EIA 12 dB SINAD 0.30 mV 20 dB QUIETING 0.50 µV Squelch Sensitivity 0.25 mV threshold Selectivity -70 dB Inter modulation -70 dB Modulation Acceptance Bandwidth ± 7.5 kHz Spurious and Image 70 dB mx Audio Power Output 5 Watts @ % distortion into 4 ohm load) Frequency Stability ± 0.
MONOGRAM SERIES LBI-38864B SPECIFICATIONS TRANSMITTER (PER EIA RS-152-B) RF Power Output 40 W (adjustable) RF Output Impedance 50 ohms Spurious and Harmonics -70 dBc Modulation 16 K0F3E FM Hum and Noise -45dB nominal Audio Distortion < 3 % @ 1000 Hz Frequency Stability ± 0.0005% Operational Bandwidth 10 MHz (3 dB degradation at band limits) VHF PROGRAMMING CHART TRANSMIT Frequency Spread Band Width Factory Programmed Freq.
MONOGRAM SERIES LBI-38864B SPECIFICATIONS OPTIONS AND ACCESSORIES CONTROL STATION OPTIONS: Power Supply MGPS5V External Speaker MGZM7C Desk Microphone MGMC5H NOT SHOWN: Antenna - MGAN1A Relay Kit - MGSU1C Noise Suppression Kit - MGPD1A Page -4Nov.
MONOGRAM SERIES LBI-38864B 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-38864B GENERAL DESCRIPTION GENERAL DESCRIPTION Introduction The Conventional Monogram Series Radio is a rugged, two-way FM mobile radio which operates in either the 148-165 MHz band split or the 160-174 MHz band split. The Monogram is a synthesized radio utilizing microcomputer technology to provide reliable high-quality simplex two-way mobile communications.
MONOGRAM SERIES LBI-38864B 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/OFF/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-38864B 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-38864B GENERAL OPERATION GENERAL OPERATION • NOTE: The following description briefly outlines the operation of your VHF synthesized mobile radio. Consult the operator’s manual for a complete description of all the modes of operation. 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-38864B GENERAL OPERATION DIGITAL CHANNEL GUARD Channel Guard provides a means of restricting calls to specific radios through the use of a CTCSS (Continuous Tone Coded Squelch) or DCS (Digitally Coded Squelch). The tone frequencies range from 67 Hz to 250.3 Hz and there are 83 programable codes. Channel Guard tone frequencies and codes are software programmable. Both tone frequencies and digital codes may be mixed on each channel. The frequencies and codes are shown in Tables 1 and 2.
MONOGRAM SERIES LBI-38864B 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 D12. In receive mode, D12 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-38864B CIRCUIT ANALYSIS Squelch The presence of an RF carrier is determined by noting the level of ultrasonic noise at the detector output (pin 9) 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 L5, L6 C48 and C50. This filter passes 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-38864B CIRCUIT ANALYSIS Reference Oscillator Crystal X3, varactor diode D119, a thermistor/resistor network and oscillator stage of IC108 from a temperature compensated 10.24 MHz oscillator. This frequency is divided by 2084 to generate the 5 kHz reference frequency for the PLL frequency synthesizer. This reference determines the frequency stability of the overall radio.
MONOGRAM SERIES LBI-38864B 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-38864B 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-38864B 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 Auxillary Relay P.C.B. 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-38864B PROGRAMMING INSTRUCTIONS PROGRAMMING INSTRUCTIONS The VHF 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-38864B TEST EQUIPMENT SETUP TEST EQUIPMENT SETUP * * Figure 4 - Test Equipment Setup * Optional Test Equipment Page -18Nov.
MONOGRAM SERIES LBI-38864B ALIGNMENT PROCEDURE ALIGNMENT PROCEDURE • WARNING: Any repairs or adjustments should be made under the supervision of a certified technician. SUGGESTED TEST EQUIPMENT The following equipment, or its equivalent, is required for proper alignment of your VHF 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 MΩ input impedance. 3. SINAD Meter. 4. FM Communications Monitor. 5.
MONOGRAM SERIES LBI-38864B 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. PLL ALIGNMENT 1. Connect an RF dummy load or power attenuator (50 watt minimum rating) to the antenna connector. 2. Connect a VOM or DVM to TP1, accessed through a hole in the VCO cover. 3. Set the CHANNEL selector to the highest transmit frequency. 4.
MONOGRAM SERIES LBI-38864B 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. Repeat step 6 above for the lowest, middle, and highest frequency transmit channel with the goal to achieve the least variation in power output across the band. 8. Increase the power supply voltage to 13.8 VDC measured at the radio during transmit. DCS Modulation Balance Adjustment 1.
MONOGRAM SERIES LBI-38864B 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 750 Hz. Release the PTT switch. 5. Set the CHANNEL selector to a transmit channel which has a low-frequency CTCSS tone (67.0Hz) preprogrammed. 6.
MONOGRAM SERIES LBI-38864B ALIGNMENT PROCEDURE 9. Adjust T6 and T7 for maximum sensitivity. These adjustments have a very broad range where little change in sensitivity is noted while the adjustment is being made. The slugs should be set in the middle of this range. 10. Check the sensitivity at the lowest and highest receive frequencies. If necessary, repeat steps (8) and (9) above at the lowest middle and highest frequencies for the best overall sensitivity. Receiver Squelch Adjustment 1.
MONOGRAM SERIES LBI-38864B ALIGNMENT POINTS 406041-F Issue:H DIGITAL BOARD ALIGNMENT POINTS 406041-F Issue:H DIGITAL BOARD Page -24Nov.
MONOGRAM SERIES LBI-38864B ALIGNMENT POINTS 406039-E Issue:H RF BOARD ALIGNMENT POINTS 406039-E Issue:H RF BOARD Page -25Nov.
MONOGRAM SERIES LBI-38864B 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 wattmeter and dummy load to the antenna connector. 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-38864B 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-38864B PERFORMANCE TEST Audio Output 1. Increase the RF signal generator/service monitor RF level to 1000 µV. 2. Connect a 4 ohm audio dummy load to the AUXILIARY speaker jack. 3. Connect a true RMS audio volmeter (the audio distortion analyzer may include this function) to the speaker leads. 4.
MONOGRAM SERIES LBI-38864B 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 VHF synthesized mobile radio.
MONOGRAM SERIES LBI-38864B COMPONENT REPLACEMENT SURFACE MOUNT COMPONENT REPLACEMENT 1. "Tin" one terminal end of the new component and the corresponding pad of the PCB. Use as little solder as possible. 2. Place the component on the PCB pads, observing proper orientation for capacitors, diodes, transistors, etc. 3. Simultaneously touch the "tinned" terminal end and the "tinned" pad with the soldering iron. Slightly press the component down on the board as the solder liquefies.
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.
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PRINTED CIRCUIT BOARD LAYOUT Page -32.0Nov.
MONOGRAM SERIES LBI-38864B TOP VIEW 406041-F ISSUE: H / DIGITAL BOARD TOP VIEW 406041-F ISSUE: H / DIGITAL BOARD Page -32.1Nov.
MONOGRAM SERIES LBI-38864B BOTTOM VIEW 406041-F ISSUE: H / DIGITAL BOARD BOTTOM VIEW 406041-F ISSUE: H / DIGITAL BOARD Page -32.2Nov.
MONOGRAM SERIES LBI-38864B TOP VIEW 406039-E ISSUE: H / RF BOARD TOP VIEW 406039-E ISSUE: H / RF BOARD Page -32.3Nov.
MONOGRAM SERIES LBI-38864B BOTTOM VIEW 406039-E ISSUE: H / RF BOARD BOTTOM VIEW 406039-E ISSUE: H / RF BOARD Page -32.4Nov.
MONOGRAM SERIES LBI-38864B PRINTED CIRCUIT BOARDS PRINTED CIRCUIT BOARDS DISPLAY BOARD TOP VIEW DISPLAY BOARD BOTTOM VIEW VOLUME BOARD BOTTOM VIEW VOLUME BOARD TOP VIEW Page -32.5Nov.
MONOGRAM SERIES LBI-38864B PRINTED CIRCUIT BOARDS 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-38864B VOLTAGE CHARTS VOLTAGE CHARTS Page -32.7Nov.
MONOGRAM SERIES LBI-38864B VOLTAGE CHARTS VOLTAGE CHARTS Page -32.8Nov.
MONOGRAM SERIES LBI-38864B VOLTAGE CHARTS VOLTAGE CHARTS Page -32.9Nov.
MONOGRAM SERIES LBI-38864B VOLTAGE CHARTS 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 - 33.0 Oct.
MONOGRAM SERIES LBI-38864B EXPLODED VIEW PARTS LIST EXPLODED VIEW PARTS LIST Page - 33.1 Oct.
MONOGRAM SERIES LBI-38864B EXPLODED VIEW PARTS LIST EXPLODED VIEW PARTS LIST Page - 33.2 Oct.
MONOGRAM SERIES LBI-38864B MGM-148 / MGM-160 EXPLODED VIEW MGM-148 / MGM-160 EXPLODED VIEW Page - 33.3 Oct.
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-38864B RF BOARD R29/406039-E 34.
LBI-38864B DIGITAL BOARD R29/406041-F 34.
