Ericsson LBI-38653 Maintenance Manual
LBI-38653
Maintenance Manual
TABLE OF CONTENTS
MAIN BOARD ASSEMB LY........................................... LBI-38760
FRONT PANEL ASSEMBLY ..................................... .... .LBI-38757
POWER AMPLIFIER ASSEMBLY.................................LBI-38761
SERVICE SECTION ...................................... ..................LBI-38759
MDS
440-512 MHz MOBILE RADIO
COMBINATION
Mobile Communications
Printed in U.S.A.
Copyright© February 1992, Ericsson GE Mobile Communications Inc.
TABLE OF CONTENTS
Page
SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
PACKAGE NUMBERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
OPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
RADIO DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
MAIN BOARD ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
FRONT PANEL ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
POWER AMPLIFIER ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
PC PROGRAMMABLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
BATTERY POWER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
EXTERNAL SPEAKER (Optional) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
EASY A CCESSIBILITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
DETAILED TYPE 99 OPERATION AND PROGRAMMING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
GE TYPE 99 FORMAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
MOTOROLA FORMAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
MECHANICAL PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
MECHANICAL PARTS BREAKDOWN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
FIGURES
Figure 1 - MDS Conventional Radio Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
TABLES
Table 1 - Channel Guard Tone Frequencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Table 2 - Primar y Dig ital and E quivalent Digital Codes (OCTAL) . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Table 3 - T o n e Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Table 4 - Tone Generator Frequencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Table 5 - Motorola Type Coder Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Table 6 - Motorola G roup C all Tone Groups (TG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Table 7 - Motorola G roup C all Tone Groups (TG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
SPECIFICATIONS
GENERAL
Frequency Range Transmit: 440-470 MHz (UHF MID SPLIT)
470-512 MHz (UHF HI SPLIT)
Receive: Same as Transmit
Channel Spacing 25 kHz
Frequency Stability ±5.0 ppm
Operating T e m p er at ur e Ran ge -30 to +60°C
Battery Volta ge 13.6 volts ±10% (meets specs)
±20% (operational)
Radio Current Drain OFF: 0.01 amps
RX Squelched: 0.9 amps
RX On: 1.5 amps
TX On: 10.0 amps
Size 170mm W x 216mm L x 53mm H
TRANSMITTER
TX Two Frequency Sprea d Full Band split
RF Power Output 40 watts min (+146 dBm)
Maximum Deviation ±5% kHz peak
TX Duty Cycle 20% Intermittent (EIA)
FM Hum and Noise (EIA) -45 dBc maximum
Audio Distortion 5% @ 300 Hz, 3% @ 1 kHz, 5% @ 3 kHz
RF Load Impedance 50 ohms
Audio Sensitivity 80 mV ±3 dB
Audio Frequency Response Within +1,-3 dB of a 6 dB/octave pre-emphasis,
300-3000 Hz (EIA)
Spurious Emissions
Conducted -16.5 dBm max (Meets DOC & FCC)
Radiated -13 dBm max (FCC)
RECEIVER
Receiver coverage 440-470 MHz, 470-512 MHz
Factory Tuned 450-462 MHz, 470-482 MHz
RX Two Freq Spread 12 MHz (No degradation)
Channel Spacing ±25 kHz
Sensitivity (12 dB SINAD) -117 dBm (.30 µV)
LBI-38653 LBI-38653
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INTRODUCTION
The Ericsson GE Conventional MDS Radio is a rugged
two-way FM mobile radio which operates in the 440-470
MHz and 470-512 MHz frequency bands. The MDS is a w id e
band 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 of each split. The receiver has an allowable 12 MHz maximum receive channel separation. There are
two versions available for each split, a 2-channel and an 8channel. The basic radio package includes the following features:
• Microprocessor Control
• Synthesized RF Channel selection (frequency control)
• 7-Segment LED Channel Display
• Multi-tone Channel Guar d (C TCSS) Encode/Decode
• Multi-code Digital Channel Guard (DCG) Encode/De-
code
• Automatic Hook Switch Channel guard Disable
• Channel Activity Sensing (CAS)
• Carrier Control Timer (CCT)
• ±5 ppm frequency stability
• Talkaround, radio to radio direct Communicat ion
• Type 99 Tone Decode
• Field Programmable with PC
• Fixed Squelch, threshold programmable
• Internal 4-watt Speaker, with volume control
• Front Mounted Microphone Connector
• Rear Mounted Antenna TNC Connector
• Rear entry power connections
• ANI Encode
The small size of the MDS radio makes it ideal for front
mounting in conventional vehicles. Th e r ad io i s oper ated with a
simple hand held microphone in combination with the f ollowing
operating controls, all located on the front panel.
• Power ON/OFF Switch
• Channel UP/DOWN Selector
• Volume UP/DOWN Control
• Monitor Switch for Channel Guard Disable
• Type 99 Tone RESET Switch , to reset the t one deco de r.
Refer to the Operator’s Man ual LBI-38651 for a complete
description of the operating procedures.
RADIO DESCRIPTION
MAIN BOARD ASSEMBLY
A sturdy aluminum casting houses the Main Board Assembly (N29/85154001220 for the 440-470 MHz band
N29/85154001250 for the 470-512 MHz band). There is complete accessibility to the Main Board with the radio’s top and
bottom covers removed. The Main Board contains the following
circuits:
• Microprocessor and associated Logic
• Frequency Synthesizer
• Transmitter Excite r
• Receiver
• Audio Processing (for both transmit and receive paths)
• Tone and Squelch Processing (for both transmit and
receive paths)
• Voltage Regulators
Logic Circuitry
The radio’s logic circuitry includes the 80C535 microprocessor with associated EPROM and Electrically Er as able PROM
(EEPROM) memory and latch circuitry. The Microprocessor
controls the functions of the transmitter, the receiver, the inputs
from the operator and the outpu ts to the op er ator.
Synthesizer
A programmable Synthesizer generates both transmit and
receive operating frequencies. It includes a synthesizer chip, a
dual modulus counter, a temperature compensated reference
oscillator (TCXO) a nd a v oltag e co ntrol led o sci llator ( VCO); a ll
part of an operating phase lock loop, with its requisite loop filte r.
Transmitter
The radio transmitter includes the Synthesizer’s m odulate d
VCO and the fixed tuned exciter amplifiers. The exciter amplifiers are wideband, covering both splits in the UHF band without
retuning. The exciter output is fed to the Power Amplifier Board
through a coax cable. The exciter provides 35 dB of gain to drive
the Power Amplifier with 3 watts. Th e tra nsmitter output level
at the antenna connector is factory set for a rated output power
of 40 watts. The power control circuit detects the power output
of the Power Amplifier. Using the error signa l, the power con trol
circuit varies the DC supply voltage to the first stage of the
exciter. This will hold the transmitter output level constan t.
SPECIF IC AT I O NS ( Co n t .)
Spurious Emissions
Radiated Meets FCC requirements
Conducted -57 dBm maximum
RX Spurious Response 70 dB minimum
Adj Ch(2-Sig) Selectivity -70 dB max @ 25 kHz (EIA)
Intermodulation Attenuati on -70 dB minimum
RX Modulation Acceptance ±7 kHz minimum
Audio Distortion 2% maximum @ 0.5 Watt (EIA)
10% maximum @ 4 Watts and 1 kHz
Audio Frequency Response Within +2, -8 or a 6 dB/octave de-emphases,
300-3000 Hz (EIA)
RX Hum and Noise
Unsquelched -45 dB maximum
Squelched -70 dB maximum
Audio Output Power 4 watts, @ < 10% Distortion
Speaker Impedance 4 ohms
MDS RADIO PACKAGE NUMBERS
MDS RADIO PACKAGE NUMBERS
PACKAGE NUMBER DESCRIPTION
TLU22 UHF MID-SPLIT 2 CHANNEL, 40 WATT
TLU28 UHF MID-SPLIT 8 CHANNEL, 40 WATT
TLU32 UHF HI-SPLIT 2 CHANNEL, 40 WATT
TLU38 UHF HI-SPLIT 8 CHANNEL, 40 WATT
OPTIONS
OPTION NUMBER DESCRIPTION
MC3G DESK TOP MIC
AN1R 1/4 WAV E, ROOF MT ANTENNA W/TNC CONNECTOR
ZM3L EXTERNAL WEATHERPROOF SPEAKER AND CABLE
LS1F MIL SPEC SPEAKER, 4 OHMS, 5 x 5
CD1E SPEAKER CABLE
PD1A NOISE FILTER KIT
SU1C ALARM RELAY KIT
EC1A DOC POWER SET
MA1L DESK T OP RADIO MOUNTING WEDGE
PS1D 240 VAC-12 VDC, 13A 50/60 Hz Power Supply
PS5K 120 VAC-12 VDC, 13A 50/60 Hz Power Supply
LBI-38653 LBI-38653
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