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NEDSP1962-KBD User Installation Manual 

 

1.

 

Introduction 
 

The NEDSP1962-KBD amplified DSP noise cancelling module can be retrofitted inside many types of 
extension speaker or older style radios and transceivers.  It incorporates unique Digital Signal 
Processing (DSP) technology which can identify speech from within a noisy signal and can provide up 
to 40 dB of noise reduction and 65 dB of tone reduction.  The module comes pre-wired and with an 
on-board power amplifier enabling it to be easily incorporated into existing equipment.  All the 
module functions are controlled by the pre-wired keyboard switch assembly.   The 

NEDSP1962-KBD 

uses a  powerful programmable DSP audio processing chip with DSP noise cancelling technology 
inside

. This high−performance chip delivers exceptional sound quality and incorporates a full audio 

signal chain with 16−bit A/D converters and di

gital interfaces utilising fully flexible digital processing 

architecture.  The audio amplifier stage is provided by a Texas Instruments TPA3111D1PWPP Mono 
Class-D audio power amplifier chip which is 94% efficient, eliminating the need for heatsinks.

 

 

1.1 The NEDSP1962 Module features:

 

 

Fully adaptable noise cancellation 9 to 40dB (8 filter levels) 

 

Up to 65% heterodyne tone reduction  

 

Overall Gain control 

 

Input level overload indicator 

 

Easy to install between input and loudspeaker 

 

Frequency Response (50 Hz to 5 kHz) 

 

Up to 7.5 Watts output (4

 

Noise Reduction can be preset or remotely set during operation 

 

10 to 18 Volts DC supply range 

 

Adjustable audio indicator 

“beep” tones 

 

 

Pcb Mounting Holes 

 

Audio bypassed when power removed 

 

Small Size 70 mm x 50 mm x 12 mm 

 

The NEDSP1962-KBD DSP noise cancelling module is supplied with 1 x 1030-FPL fused DC power 
lead, full mounting kit with bhi labels and installation user guide. 

 

1.2

 

Limitations 

 

This module is designed to pass speech.  Other signals such as data, music and morse (CW) will pass 
through to some degree depending on the filter level setting, but the integrity of these signals 
cannot be guaranteed. This module is designed to be driven from a High-Level signal source capable 
of operating into a load of 62

 impedance.  

Important Note:

  

The Audio Output Amplifier is ‘Class D’ and therefore neither of the output wires 

should have any connection to ground, they should only be connected to a speaker or a fully 
isolated socket for headphones.  

 

1.3

 

Module connection and mounting  

 

The module comes pre-wired with a  2.1 mm power socket fitted (centre pin +ve). The 

audio in

 

and 

“audio 

out

 connections are pre-wired pairs of wires, ready to be connected into the audio path 

Содержание NEDSP1962-KBD

Страница 1: ...9 to 40dB 8 filter levels Up to 65 heterodyne tone reduction Overall Gain control Input level overload indicator Easy to install between input and loudspeaker Frequency Response 50 Hz to 5 kHz Up to...

Страница 2: ...y the label see figure 3 above Do not over tighten the mounting screw If the enclosure is too thin to use a countersunk screw such as fitting into sheet metal then an Instrument Head type screw may be...

Страница 3: ...3 2 1 Block Diagram of module Figure 4 NEDSP1962 block diagram...

Страница 4: ...switch assembly 2 1mm power socket with retaining nut and washer Power socket hole diameter 8mm Audio output wires White to speaker ve Blue to speaker ve Audio input wires Yellow audio input Black Si...

Страница 5: ...there is an Audio Overload or Fault condition There is also an overload LED on the main pcb LED Status Indicator A Tri colour LED is provided on the keyboard PCB indicates the various module modes 2...

Страница 6: ...from this module it should be set up such that the output level sounds the same whether the module is switched On or Off The input sensitivity has a range of 70mW to 3 Watts to provide a 7 Watt outpu...

Страница 7: ...give you increased audio output Bear in mind that if the user may get a bit of a shock when the module is powered and the volume suddenly changes from a normally acceptable level to one that s quite l...

Страница 8: ...0 Functions 4 1 Keyboard switch assembly The keyboard has 2 push buttons a Tri coloured LED and a Red LED Overload Fault Indicator Red Power On Off button Mode button Mode Indicator Tri colour M3 Moun...

Страница 9: ...dule Off With the power connected and the module switched Off the circuit will still draw approximately 6mA 4 1 2 DSP Level Button This function button is used to set the following DSP filter On Off D...

Страница 10: ...be heard indicating that the module is in the set up mode followed by three sets of two beeps then followed by 4 beeps and then 8 beeps Keep your finger on the mode button until you want to select eit...

Страница 11: ...to 18 V 70 80 mA Current at Maximum Audio 400mA Audio Characteristics Parameter Test Conditions Min Typ Max Units Output Power Vs 10 V to 18 V 5 7 W Input Sensitivity 4 Load f 1kHz Po 0 5 W 100 mV p p...

Страница 12: ...0 Physical Dimensions The following diagrams detail the physical dimensions of the module All dimensions are 6 1 Main PCB Physical dimensions 6 2 Keyboard hole drilling detail below drawing not to sc...

Страница 13: ...ed or that one of the speaker wires has been grounded Check the speaker and or wiring for faults before trying to switch the module on again If the speaker works when the module is switched Off i e th...

Страница 14: ...14 bhi Ltd 22 Woolven Close Burgess Hill West Sussex RH15 9NR England Telephone 44 0 1444 870333 Email sales bhi ltd com Web www bhi ltd com...

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