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Noise Reduction Module
Model A121
Installation Instructions
Description
The 3M Noise Reduction Module (3M part number 78-9236-6403-7) improves the inbound intelligibility of an
intercom system by reducing environmental background noise from vehicles, airplanes, noisy intersections, etc.
Additional Material Required
•
18 - 22 AWG twisted - shielded pair audio wire
•
2 mounting screws and appropriate wall anchors
Important: The 3M Noise Reduction Module should be mounted no more than 3 feet from the intercom or base
station.
System Requirements
The 3M Noise Reduction Module requires a system with a separate outside microphone and speaker. The A121 will
not function with an intercom system configured to use a single speaker as both the microphone and speaker. The
A121 will work in conjunction with most dynamic microphones and speaker/microphone assemblies.
System Configuration
The 3M Noise Reduction Module configuration is controlled by two jumper switch (JMP1 and JMP2) settings.
JMP1 is used to set the appropriate gain for the MENU MICROPHONE.
JMP2 is used to match the A121 output level to the input of the intercom system.
Jumper
Position
Position A
JMP1
* Separate microphone
& speaker at menu
sign/post
JMP2
* 3M Intercom
Note: * Indicates factory default settings
Table 1. 3M Noise Reduction Module Jumper Settings
Position B
Do not use this position
HME Intercom
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Related Manuals for 3M A121
Summary of Contents for 3M A121
- Page 1 18 - 22 AWG twisted - shielded pair audio wire • 2 mounting screws and appropriate wall anchors Important: The 3M Noise Reduction Module should be mounted no more than 3 feet from the intercom or base station. System Requirements The 3M Noise Reduction Module requires a system with a separate outside microphone and speaker.
-
Page 2: Mode Configuration
Fault Condition Table 3. 3M Noise Reduction Module Status Indication Final Checkout Procedure 1. Turn the ON/OFF switch of the A121 ON. The red LED should blink slowly. Listen for a reduction in the background noise. ON Position Test Mode (Factory use only;... -
Page 3: Troubleshooting
2. If the A121 is in a half-duplex system, set SW2 number 2 OFF and proceed to step 3. If the A121 is in a full-duplex system set SW2 number 2 OFF. Speak into the headset mic or intercom mic. - Page 4 Figure 2. Wiring for 3M C760/960/1060 Base Station with Interconnect Module...
- Page 5 MENU SPKR AUDIO OUT ALT ALERT VEH DET ALERT OUT 12V UNREG To Vehicle Detector Figure 3. Wiring for 3M C760/960/1060 Base Station with 3M Audio-Level Control Module A121 Noise Reduction Module MENU INTERCOM MIC IN MIC OUT MIC IN...
- Page 6 ALT ALERT VEH DET ALERT OUT INTERCOM SPKR INTERCOM SPKR 12V UNREG INTERCOM MIC INTERCOM MIC Figure 5. Wiring for 3M C760/960/1060 Base Station with A300 Audio Greeter TIMER TRIG MSG4 TRIG VEH DET- VEH DET VEH DET+ MUSIC MUSIC...
- Page 7 Noise Reduction Module Menu Post MENU MIC MENU SPKR Figure 6. Wiring for Panasonic WX-C510/WX-C1010 Base Station A121 Noise Reduction Module MENU INTERCOM MIC IN MIC OUT MIC IN MIC OUT SHLD SHLD MENU MENU SPKR SPKR MENU MENU SPKR SPKR Figure 7.
- Page 8 MENU SPKR MENU SPKR MENU SPKR MIC OUT MENU MIC MIC OUT MENU MIC Figure 8. Wiring for HME SYS2500D/DS/DSL Base Station with 3M A300 Audio Greeter VEHICLE DETECTOR OUTPUT 3M A121 Noise Reduction Module MENU INTERCOM MIC IN MIC OUT...
- Page 9 MIC OUT MIC IN MIC OUT SHLD SHLD MENU MENU SPKR SPKR MENU MENU SPKR SPKR 3M A121 Noise Reduction Module © 3M 2006 May SYS2500D/DS/DSL Base Station SHLD BLACK SPKR/MIC VEH DET SIG VEH DET GND BLACK WHITE OUTSIDE SPEAKER GREEN 78-6912-0699-5 Rev.