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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
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Mode Configuration The 3M Noise Reduction Board can be configured in several different modes by setting DIP switch, SW2. Following is a brief description of each mode and a DIP switch setting table. Noise Reduction: With SW2 number 1 ON, the inbound microphone voice signal is digitized. The noise is digitally removed from the voice and converted back to an analog voice signal. The analog voice signal is then sent to the microphone input of the intercom. Echo Reduction: With SW2 num
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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. The echo should increase. Turn SW2 number 2 back ON. The echo should decrease. 3. Set SW2 number 3 for appropriate level of noise reduction. Set SW2 number 3 OFF for restaurant mode . Set SW2 number 3 ON for truck stop mode. 4. Set SW2 number 4 (Hi Frequency Equalization) to customer’s preferen
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Figure 2. Wiring for 3M C760/960/1060 Base Station with Interconnect Module 4
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A121 Noise Reduction Module MENU INTERCOM 3M Base Station 1 MIC IN MIC OUT 1 2 MIC IN MIC OUT 2 MIC 3 SHLD SHLD 3 MIC MENU MENU 4 4 SHIELD SPKR SPKR MENU MENU 55 MENU SPKR SPKR SPKR MENU SPKR Menu Post MIC OUT COM MENU SPEAKER MENU MIC OUT AUDIO OUT SPKR ALT ALERT SHLD SHLD VEH DET VEH DET MIC IN MENU MIC COM MIC IN ALERT OUT COM AUDIO IN 12V UNREG 3M Audio-Level Control To Vehicle Detector Figure 3. Wiring for 3M C760/960/1060 Base Station with 3M Audio-Level Control Module 3M D15/D30 I
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A300 Audio Greeter Optional Service Timer C921AA Base Station 12 MIC TIMER TRIG 11 MIC COM 10 SHIELD MSG4 TRIG COM 9 MENU SPKR VEH DET- 8 VEH DET VEH DET+ 7 MENU SPKR 6 MON SPKR COM 5 MUSIC COM 4 AUDIO IN MUSIC 3 AUDIO OUT COM _____ 2 ALT ALERT TALK AUDIO IN 1 VEH DET AUDIO OUT J9 ALERT OUT 10 MENU SPKR COM INTERCOM SPKR 9 MENU SPKR INTERCOM SPKR 12V UNREG 8 COM A121 Noise Reduction Module 7 MIC INTERCOM MIC 6 MIC INTERCOM MIC Menu Post MENU INTERCOM 5 MENU SPKR MENU SPKR 1 MIC IN MIC OUT 1 4 ME
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SP/MIC SP DET 12VAC MIC Panasonic WX-C510/WX-C1010 Base Station H C GND C H H A121 C Noise Reduction Module Menu Post H MENU INTERCOM 1 MIC IN MIC OUT 1 COM MENU MIC 2 MIC IN MIC OUT 2 GND 3 SHLD SHLD 3 AC MENU MENU 4 4 SPKR SPKR AC MENU SPKR MENU MENU 55 SPKR SPKR Figure 6. Wiring for Panasonic WX-C510/WX-C1010 Base Station HME SYS2500/DS/DSL Base Station MIC/SPKR MIC/SPKR SHIELD OUTSIDE SPKR A121 Noise Reduction Module OUTSIDE SPKR MENU INTERCOM 1 MIC IN MIC OUT 1 MIC IN MIC OUT 2 2
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VEHICLE ** Note: DETECTOR Set A300 vehicle detector 5 HME trigger polarity to negative (set 3M A300 6 SW2 number 3 OFF and SYS2500D/DS/DSL Audio Greeter JMP1 to Position B). GND 7 Base Station OUTPUT * 8 12 Terminals 6 and 9 may also TIMER TRIG be used for a contact-closure 9 11 COM connection. 10 10 MSG4 TRIG ** VEH DET SIG 11 9 VEH DET- 12 8 SHLD VEH DET+ 13 7 BLACK SPKR/MIC VEH DET GND 14 6 RED COM J1 5 MUSIC 4 MUSIC 4 3 COM _____ 5 2 VEH DET SIG TALK 6 1 VEH DET GND AUDIO OUT J9 7 RED 8
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VEHICLE DETECTOR 5 HME HME MR100A 6 SYS2500D/DS/DSL Message Repeater GND 7 Base Station OUTPUT 8 6 MENU SPKR MENU SPKR 9 7 MENU SPKR MENU SPKR 10 8 GND (SHIELD) 11 9 MIC OUT MENU MIC 12 MIC OUT 10 SHLD MENU MIC 13 11 WHITE BLACK BASE SPKR CONN SPKR/MIC 14 12 GREEN BASE SPKR CONN RED J1 13 SHLD GND (SHIELD) 14 RED BASE MIC CONN 4 15 BLACK BASE MIC CONN 16 VEH DET SIG 5 VEH DET IN VEH DET SIG 6 17 VEH DET GND VEH DET OUT 7 18 RED ENABLE/DISABLE 8 19 BLACK EXT PLAY CANCEL 9 20 VEH DET GND GND WHITE
