LBI-39181 Maintenance Manual DTMF Microphone 344A4611P1 & P2 ericssonz
LBI-39181 TABLE OF CONTENTS INFORMATION TO USERS........................................................................................................................... GENERAL........................................................................................................................................................ FEATURES ...................................................................................................................................................... SPECIFICATIONS.....
LBI-39181 GENERAL Model 344A4611 is a hand-held, amplified, condenser DTMF communications microphone with an illuminated keypad. The microphone is ideal for upgrading existing twoway radios for use with advanced telephone interconnect systems or for new installations. It is designed for rugged and reliable operation in any mobile communications application. The microphone has an omni-directional pickup pattern and provides extremely clear transmission, even in noisy environments.
LBI-39181 SPECIFICATIONS (Test conditions unless otherwise specified: audio output measured between pin 2 and ground; PTT switch depressed; no hang-up button connection; mic and DTMF level trimmers full clockwise; dc VTVM 10 MΩ or greater input impedance; ac VTVM 1 MΩ or greater input impedance.
LBI-39181 Figure 2 - Overall Dimensions IMPORTANT: The microphone hang-up button is connected to the blue cable conductor for radios with microphone hang-up sensing. MICROPHONE CABLES Figure 4 - Equipment End Cable Wiring The cable is attached to the microphone by inserting the modular telephone-type plug in the microphone jack until it locks.
LBI-39181 SERVICE INSTRUCTIONS CAUTION These microphones contain static-sensitive semiconductor devices. All work must be performed at a static-free work station using properly grounded equipment. Soldering operations must be performed using a fine-pointed low-wattage soldering iron. Figure 5 - Microphone Case Rear OPERATION Operation of all microphone and DTMF functions requires that the microphone is connected to the communications equipment and that the equipment power is turned on.
LBI-39181 TO SEPARATE THE CENTER BOARD FROM THE FRONT BOARD 1. Observe that a flexible ribbon cable connects the center board to the front board. To detach this cable, with the case front still face down on the table and the cable entry still toward you, carefully unsolder the tabbed leads. 2. Rotate the case front so the voice entry port is toward you. Use the two cylindrical posts at diagonal corners of the board to lift the center board away from the front board.
LBI-39181 REPLACEMENT PARTS Cable and Modular Plug (Figure 4A) 344A4611P21 Cable and Modular Plug (Figure 4B) 344A4611 P22 OPTIONAL ACCESSORY Mounting Bracket Figure 7 - Parts Layout 344A4611 8 344A4678P1
SCHEMATIC DIAGRAM LBI-39181 (98E401-11-2) 9
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.
