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LBI-39181

6

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. Power application can be verified by observing
keypad LED backlighting.

VOICE TRANSMISSION

1.

Hold the microphone comfortably in the hand,
positioned so that the Top-Talk Sound Channels at the
top of the case are near the mouth. The clearest sound is
often obtained with the microphone at the corner of the
mouth, with the cable away from the face.

2.

Press the push-to-talk button and make sure the
equipment is in the transmit mode before speaking.

3.

Release the push-to-talk button before dialing.

DIALING

1.

Do not depress the push-to-talk button.

2.

Press the desired keypad buttons in sequence. A high-
pitched tone will confirm that the code has been
transmitted.

3.

When the first keypad button is pushed, the transmitter
is automatically keyed. The transmitter will remain
keyed for approximately 1.5 seconds after the button is
released.

SERVICE INSTRUCTIONS

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.

CAUTION

TO DISASSEMBLE THE MICROPHONE

1.

Disconnect the microphone and remove the cable.

2.

Remove the four Phillips-head screws from the back of
the microphone.

3.

Hold the microphone with its back toward you and the
cable connector down. Carefully separate the case back
slightly from the front. Pivot the case back to the right
taking care not to damage any internal leads or
components. Observe that four leads attach the leaf
switch to the boards, and one blue lead attaches the rear
board to the terminal in the center of the case back.

TO DETACH THE CASE BACK AND REAR
PRINTED CIRCUIT BOARD

1.  With the partially disassembled microphone face down

on a flat surface and with the cable entry toward you,
locate the multipin connector on the left side between
the center board and the rear board. Carefully pry the
rear board away from the connector on the center board.
(To start the process, the flat blade of a small
screwdriver can be inserted between the terminal pins
connected to the rear board and the connector attached
to the center board.)

2.

Lift the microphone case back and the rear board away
from the center board.

The center board contains static-sensitive
semiconductor devices that can be functionally
damaged by handling. Make certain proper
procedures are followed when working with this
board.

CAUTION

Summary of Contents for 344A4611P1

Page 1: ...LBI 39181 ericssonz Maintenance Manual DTMF Microphone 344A4611P1 P2 ...

Page 2: ...to which the receiver is connected Consult the dealer or an experienced radio TV technician for help Copyright September 1995 Ericsson Inc CREDITS MODULINK ARMO DUR Million Cycle Plus and Top Talk Sound Channels are trademarks of Shure Brothers Inc NOTICE This manual covers Ericsson and General Electric products manufactured and sold by Ericsson Inc NOTICE Repairs to this equipment should be made ...

Page 3: ...gned it fits naturally and comfortably in the hand and is not affected by heat or humidity The rugged ARMO DUR case is immune to oil grease most fumes and solvents salt spray sun rust and corrosion It is outstanding in its ability to withstand mechanical shocks and vibration The Million Cycle PIus leaf type switch is a double pole single throw type designed to resist the effects of severe operatin...

Page 4: ... respect to ground Environmental Conditions Operating Temperature 40 to 60 C 40 to 140 F Storage Temperature 54 to 85 C 65 to 185 F Relative Humidity 0 to 95 non condensing Microphone Connector 6 conductor modular telephone type PTT Switch Assembly Mechanical Double pole single throw leaf type normally open Electronic Open NPN transistor collector to ground positive polarity only maximum on state ...

Page 5: ...all screwdriver supplied with the microphone in rear case hole A just above the cable jack see Figure 5 to unlock the plug and withdraw the plug from the jack ADJUSTMENTS After connection to the communications equipment and with equipment power turned on the microphone sensitivity and DTMF output levels should be adjusted with the supplied screwdriver as follows 1 MICROPHONE SENSITIVITY Press the ...

Page 6: ...nded equipment Soldering operations must be performed using a fine pointed low wattage soldering iron CAUTION TO DISASSEMBLE THE MICROPHONE 1 Disconnect the microphone and remove the cable 2 Remove the four Phillips head screws from the back of the microphone 3 Hold the microphone with its back toward you and the cable connector down Carefully separate the case back slightly from the front Pivot t...

Page 7: ...cable Thread the cable through the slot in the board Lift the board free of the case carefully sliding the whole length of the flexible cable through the slot TO CONCLUDE DISASSEMBLY OF THE MICROPHONE The membrane switch assembly and keypad can now be lifted out of the case 1 To free the rear board from the case back unsolder the leads from the hang up button and leaf switch terminals 2 To remove ...

Page 8: ...LBI 39181 8 REPLACEMENT PARTS Cable and Modular Plug Figure 4A 344A4611P21 Cable and Modular Plug Figure 4B 344A4611 P22 OPTIONAL ACCESSORY Mounting Bracket 344A4678P1 Figure 7 Parts Layout 344A4611 ...

Page 9: ...SCHEMATIC DIAGRAM LBI 39181 9 98E401 11 2 ...

Page 10: ...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 ...

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