CONFIGURATION 14:
DTMF MICROPHONE ZONE PAGING
This section will describe the configuration for the use of a Shure microphone Model 885TT with DTMF dialing capabilities and the MODULINK five- conductor
In addition to the PCM2000 system and associated amplifiers, the model numbers and components required for this configuration are:
1- Shure Microphone model 885TT
1- Shure MODULINK coil cord model
1- 680 ohms
Paging with a DTMF Shure condenser microphone is a
Note:The Shure microphone model 885TT requires a modification in order to operate properly with the PCM2000 zone paging modules.
SHURE 885TT MODIFICATION: STEP 1: Disassembling the Microphone
•Remove the cable, if attached, to the microphone using a paper clip.
•Remove the four
•Hold the microphone with its back toward you and the cable connector down, and 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.
STEP 2: Detaching the Case Back and Rear Printed Circuit Board
•With the partially disassembled microphone face down on a flat surface and with the cable entry toward you, locate the
•Carefully pry the rear board away from the connector on the centerboard.You may need a small flathead screwdriver to separate the terminal pins connected to the rear board and the connector attached to the center board.
•Lift the microphone case back and the rear board away from the center board.
STEP 3: Modification
• Locate pin 5 on the solder side of the J303 phone jack (cable entry) and cut the trace around pin 5, disconnecting it from ground.
•Locate the black wire connected from the microphone switch to the first printed circuit board and unsolder it from the board.
•Solder the black wire disconnected previously from the first P.C. board to pin 5 on the soldered side of the J303 phone jack (cable entry).
•Locate transistor Q303 on the component side and clip or unsolder the collector lead.
STEP 4: XLR Connector Setup
•An XLR connector (not included) is recommended.
•Solder the XLR connector to the Shure microphone coil cord MODULINK model
•Solder a
•
STEP 5: Reassembling
•Reassemble the microphone by reversing the steps of disassembly.
OPERATION:
•Connect the XLR connector to MIC socket.
•Press and keep pressed the microphone switch.
•Dial the two digits to access the zone desired or dial 00 for
•Make a page.
•Release the microphone switch.
•Repeat procedure to page again.
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