LBI-38435B Maintenance Manual MLS 29.7-42 MHz, 42-50 MHz 60 WATTS TWO-WAY FM MOBILE RADIO COMBINATION INCLUDES TRANSMITTER/RECEIVER ..................................................LBI-38436 SYSTEM CONTROL/SYNTHESIZER....................................LBI-38437 FRONT PANEL/CONTROL UNIT ..........................................LBI-38424 SERVICE SECTION ..............................................................
LBI-38435B NOTICE! The software contained in this device is copyrighted by Com-Net Ericsson Critical Radio Systems, Inc. Unpublished rights are reserved under the copyright laws of the United States. This manual is published by Com-Net Ericsson Critical Radio Systems, Inc., without any warranty.
LBI-38435B TABLE OF CONTENTS SPECIFICATIONS..................................................................................................................................................4 DESCRIPTION........................................................................................................................................................6 OPERATION .................................................................................................................................................
LBI-38435B SPECIFICATIONS* SYSTEM Radio Type FCC# MLSL161 (29.7-42 MHz) MLSL261 (42-50 MHz) Frequency Range: Transmitter Receiver Transmitter Receiver 29.7 to 42 MHz, 42 to 50 MHz 29.7 to 42 MHz, 42 to 50 MHz Two Frequency Spread 1 MHz Two Frequency Spread 1 MHz Battery Drain: Receiver (13.8 VDC) Off Squelched Unsquelched 0.03 Amperes 0.70 Amperes nominal 1.15 Amperes (4 Watt audio) Transmitter (13.6 VDC) 20.
LBI-38435B SPECIFICATIONS* (Continued) Distortion Less than 3% (1000 Hz) Less than 5% (300 Hz to 3000 Hz) Deviation Symmetry + 0.5 kHz (maximum) RF Output Impedance 50 ohms Carrier Attack Time 30 milliseconds (maximum) Audio Attack Time 50 milliseconds (maximum) RECEIVER Audio Ampl Output (4-ohm speaker) 4 Watts (less than 5% distortion) EIA Sensitivity 12 dB SINAD (EIA method) 20 dB (Quieting method) 0.35 microvolts 0.
LBI-38435B DESCRIPTION The Com-Net Ericsson MLS series mobile radio is a synthesized, wide-band radio, utilizing microcomputer technology to provide high reliability, high quality, and high performance in two-way, FM, mobile communication. The MLSL161 and MLSL261 radios operate in the 29.7 to 42 MHz and the 42 to 50 MHz frequency ranges respectively and provide an RF power output of 60 watts with an allowable channel separation of 1 MHz transmit and 1 MHz receive.
LBI-38435B Figure 1 – MLS Mobile Two-Way FM Radio 7
LBI-38435B There are five (5) different optional interchangeable control panels available for selecting a two channel radio, an eight (8) or sixteen (16) channel radio.
LBI-38435B MONITOR CHANNEL A momentary type switch to allow you to monitor the selected channel before transmitting a message. It disables Channel Guard and squelch and will allow you to hear noise if the channel is not busy. This may be convenient when setting the volume to the desired listening level. Two momentary type switches. Press CHAN 1 (up arrow) to select channel 1; press CHAN 2 (down arrow) to select channel 2. The selected channel number will be illuminated on the control module.
LBI-38435B • When scan is off, the selected channel is shown. • When scan is on, the last pre-scan selected • channel is shown when no signal is being received. When a scan channel is being received and audio is present in the speaker, the received channel is shown.
LBI-38435B USING THE RADIO (2 CHANNEL) 2. Select the desired channel by pressing either the ADD or DELETE switch. To Receive a Message: 3. Press and hold MONITOR switch and then adjust the VOLUME controls for the desired listening level. Release MONITOR switch. 4. Radio is now ready to receive a message. 1. Turn the radio on (channel indicator lit). If not, press POWER switch. 2. Select the desired channel by pressing either the 1 or 2 switch. 3.
LBI-38435B channels. The scan rate will be faster when fewer channels are programmed into scan memory. • Radio is in scan mode but there is no carrier activity to top the scan on any channel. Removing the microphone from its hookswitch will stop the scanning activity and the radio will revert to the pre-scan selected channel. Replacing the microphone will enable the scan mode after a few seconds delay. • Radio is in scan mode and carrier activity on a channel has caused scan to stop.
LBI-38435B 2. Press and hold SCAN switch then press the ADD switch twice. The selected channel will now become the Priority 2 channel and the “P2” indicator will light to indicate that the channel is now in the scan program as Priority 2. 3. Release SCAN switch. USING THE OPTIONAL EIGHT (8) OR SIXTEEN (16) CHANNEL RADIO (WITH SCAN) Perform the procedure listed in the paragraph “Using the Optional Eight (8) or Sixteen (16) Channel Radio (Without Scan).” Priority 1 (P1)** 1. 2. 3.
LBI-38435B • Receiver Voltage Readings • IC and Chip Component Replacement Procedures 6. Also provided in the Maintenance Manuals for each circuit board are IC DATA SHEETS with information about each IC package used on that particular circuit board. DTMF MICROPHONE MODIFICATION 1. Remove the top radio cover and locate the System Control/Synthesizer board (A801). 2.
INTERCONNECTION DIAGRAM LBI-38435B 15
LBI-38435B 16 ILLUSTRATED MECHANICAL PARTS BREAKDOWN
MECHANICAL PARTS LIST LBI-38435B 17
INTERCONNECTION KIT 18 LBI-38435B
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Com-Net Ericsson Critical Radio Systems, Inc. P.O. Box 2000 Lynchburg, Virginia 24501 1-800-528-7711 (Outside U.S.A. 804-592-7711) Printed in U.S.A.
ADDENDUM NO. 1 TO LBI-38435B (PCML) This addendum covers connection changes when using External Speaker Option LS1D with MLS Mobile Radios. It also covers a part number change for the radio Front Cabinet. EXTERNAL SPEAKER OPTION LS1D The MLS radio is normally configured for internal speaker operation. When an external speaker is used, J551 jumper connections on the Transmitter/Receiver board must be changed.
