BHI NEDSP1061-KBD User manual

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NEDSP1061-KBD Operating Manual
Important Information
Copyright
Thispublication,includingallphotographsandillustrations
isprotectedunderinternationalcopyrightlaws,withallrights
reserved. Neitherthismanual,noranyofthematerialwithin,
may be copied or reproduced without the written consent
ofbhi Ltd.
Disclaimer
Theinformationinthisdocumentissubjecttochangewithout
notice. bhi Ltd. makes no representations or warranties
with respect to the contents hereof and specifically
disclaims any implied warranties of merchantability or
fitness for any particular purpose. Furthermore, bhi Ltd.
reserves the right to revise this publication and to make
changes from time to time in the content hereof without
obligationofbhiLtd.tonotifyanypersonofsuchrevisionor
changes.
ThefittingofthebhiNEDSP1061-KBDmodulemayinvolve
the removal of small surface mount components and the
drilling out of the transceivers’ case. This should only be
carried out by a qualified engineer. bhi accepts no
responsibilityforthefittingorinstallationoftheNEDSP1061-
KBD module and are not liable for any damage to
equipment caused by its fitment. Fitting this module may
invalidateyourwarranty.
Allattemptshavebeenmadetoensurethatthisinformation
is up to date. It is possible that these instructions contain
errors,ortheequipmentisslightlydifferent totheoneused
tocompilethisinformation.Inallcasesitisuptotheinstaller
toensurethatthe module isfittedcorrectly.

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NEDSP1061-KBD Operating Manual
Packing List:
Please check the contents of the box.
•Operating manual
•NEDSP1061-KBD assembly
•‘Z’ bracket
•Self adhesive mounting pads
•bhi NEDSP keyboard label
Toinstallthismoduleyouwillneedthefollowingadditional
items:
•service manual/circuit diagram of the equipment in
which the module is to be installed.
•all the appropriate tools to disassembling the
equipment
•suitable soldering iron and bits for working with
surface mount devices.
Before attempting to fit this module study this manual
thoroughly along with the service manual for your
equipment.

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NEDSP1061-KBD Operating Manual
1. Introduction
1.1 NEDSP1061-KBD features 6
1.2 Limitations 6
1.3 Audio DSP noise cancellation 7
2. Module description
2.1 Module layout 8
2.2 Connections 8
2.3 Electricalcharacteristics 9
2.4 Controls 9
2.4.1Input level 9
2.4.2Output level 9
2.4.3Beep volume level 9
2.4.4Overload LED 9
2.5 Modulemounting 10
3. Installation 11
3.1 Introduction 11
3.2 Circuit location 11
3.3 Fitting 12
3.3.1Audio connections 12
3.3.2Powerconnections 13
4. Setup 14
5. Troubleshooting 15
6. Operation 16
6.1 Introduction 16
6.2 Operation 16
6.3 Demonstration mode 17
6.4 Notes about noise reduction 18
6.5 Noise reduction level 18
Contents

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NEDSP1061-KBD Operating Manual
7. Machining drawings 19
Appendices
AppendixA
Yaesu FT-817 fitting instructions 20
Appendix B
Kenwood TS-50 fitting instructions 26
Appendix C
Icom 706 MKII G fitting instructions 30
Appendix D
Other bhi products 34

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NEDSP1061-KBD Operating Manual
The NEDSP1061-KBD is a modular solution to noise
reduction. It incorporates DSP technology to provide up
to 35dB of noise cancellation. The module is controlled
by a single pushbutton with LED indication for ease of
use.
1.1 NEDSP1061-KBD module features:
•Fully adaptive to changing noise environments
•Input and output level controls
•Input overload indication
•Virtually no distortion to speech signal
•Up to 35dB of noise cancellation
•4or8levelsofnoisereductionselectableonpowerup
•5 – 15V supply range
•4.6dB on board gain
•Single key operation of all functions
•LED indication of DSP level and status
•Small size 26mm x 37mm
1.2 Limitations.
This module is designed to pass speech. Other signals
such as data and music will to some degree pass
through, but the integrity of these signals
cannot be guaranteed.
Thismodule isdesignedto beplacedin alow level audio
path only. The module will not drive a loudspeaker or
other high power load (see bhi NEDSP1062-KBD
amplified DSP module).
The unit is single channel (mono).
1. Introduction.
1. Introduction.

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NEDSP1061-KBD Operating Manual
This module is designed for communication type
applications. The upper frequency limit is 4.5KHz and
therefore not suitable for hi fidelity applications.
1.3 Audio DSP Noise cancellation.
The bhi DSP processes the incoming audio signal and
then differentiates the speech from the noise. The
unwanted noise and interference is then attenuated to
leave only the speech.
The following diagrams are taken from actual audio
signals and illustrate how the audio signal is being
processed.
Figure 1. Noise cancellation.
Original signal.
Speech with a lot of
background noise
Processed speech.
Speech with reduced
noise
Speech Noise
Reducednoise
1. Introduction.

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NEDSP1061-KBD Operating Manual
2.1 Module Layout.
The following diagram shows the layout of the
NEDSP1061-KBD module.
Figure 2. Module layout.
2.2 Module Connections.
The NEDSP1061-KBD module has five connections.
Red wire: 5 - 15VDC
M3 Tag:0V
Screened Lead:Red Audio In (to module)
Blue Audio Out (from module)
Black Audio Screen
2. Module Description.
Output level
(P1) Input level (P2)
Bi-colour
LED
Beep volume
(P3)
Red wire
(5-15VDC) M3 Ring Tag
(0V)
Overload LED
Push
button
Screened audio
lead
2. Module description.

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NEDSP1061-KBD Operating Manual
2.3 Electrical characteristics.
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Table 1. NEDSP1061-KBD Electrical characeristics
2.4 Controls.
Controls are provided to allow the NEDSP1061-KBD to
be integrated in to the target system. 3 level controls are
provided.
2.4.1 Input Level:
To set the audio level to the optimum level for the DSP.
2.4.2 Output Level:
To match the output level of the DSP module to that of
the following stage.
2.4.3 Beep volume level:
Allows the user to adjust the beep volume control to suit.
The beep volume can be reduced to zero if required.
The modules are factory set to the maximum level.
Turning the potentiometers anti clock wise will increase
the levels.
2. Module Description.

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NEDSP1061-KBD Operating Manual
Note: The potentiometers do not have end stops. It is
possibletosetthepotentiometerina dead bandbetween
the ends, resulting in the audio being lost, continue
rotating and the audio will return.
2.4.4 Overload LED.
The overload LED circuit monitors the amplitude of the
audio level entering the DSP module. The LED will
illuminate when the amplitude exceeds the maximum
permitted level. If the amplitude is increased further the
DSP will clamp the audio signal to prevent damage to
theDSPinput.Thiswillcausetheaudio signal tobecome
distorted. The optimum level is achieved when the
loudest peaks of the input audio, just cause the LED to
glow.
2.5 Module mounting.
The DSP module has four mounting holes that can be
usedto retaintheunit insidetheequipment.Alternatively
a self adhesive pad is supplied to allow the module to be
mounted in a convenient position - without the need for
drilling.
Two holes need to be drilled in the casing of the
equipment for the keyboard. Hole sizes and positions
can be found in section 7 - page 19.
Thekeyboardcan retainedusingthe supplied ‘Z’bracket
oralternatively retainedusing a suitableadhesive,or the
mounting pads supplied.
In some equipment it may be possible to clamp the
bracket under the loudspeaker bracket (e.g. FT-817)
Coverthekeyboardholes withthesuppliedselfadhesive
label.
2. Module Description.

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NEDSP1061-KBD Operating Manual
connection (this screens the cable and acts as a
mechanical fixing for the cable, protecting the capacitor
pads).
3.3.2 Power connections.
5 - 15VDC (9V typically) is required to operate the
module.The lower the voltage, the less heat the module
will have to dissipate.
Locate a convenient point to connect the power. Ensure
that this point is connected after the power switch,
otherwise the DSP module will be drawing power all the
time, and may discharge the batteries (where fitted).
Connect the red wire to this point.
The 0V connection is formed using the M3 ring tag.
Locateasuitable0Vpoint(suchasaPCBretainingscrew
that is fixed into the chassis).
Whenroutingthewires,ensuretheyareawayfromstrong
sources of RF or high voltage.
3. Installation.

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NEDSP1061-KBD Operating Manual
Thelevelscomefactorysettothemaximumposition.This
should be adequate for most applications. However the
modulecanbe adjustedasfollows.
Tunethe equipmenttoastrongsignal.
Switch off the noise reduction (LED should illuminate
orangeor red).
AdjusttheinputP2untiltheoverloadledilluminates.Back
offthepotentiometer approximately a1/4ofa turn.
Adjust P1 to give the correct listening volume, without
distortion.
Adjust P3 to give the desired beep volume level, or off if
required.
4. Setup.
4. Setup

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NEDSP1061-KBD Operating Manual
6.1 Introduction.
Allfunctions oftheNEDSP1061-KBD arecontrolledby a
singlebutton.
•Singlepressturnsthenoise cancellationon/off.
•Holdingdownthebutton changestheDSPfilter
level.
The mode of operation is indicated both visually and
audibly.
TheLEDis illuminated redfor4 level mode,ororange for
8 level mode when the noise cancellation is off, and not
illuminated when the noise cancellation is on in 8 level
mode to save on battery life. The LED is green when the
filteris onin 4level mode.
WhenthenoisecancellationlevelischangedtheLEDwill
flashgreentoindicatewhichlevelhasbeenselected,and
simultaneouslytheDSPwillbeeptogiveaudibleindication
ofDSPlevel. This allowstheoperatorto changetheDSP
levelwithout havingto lookat theLED tosee whichlevel
hasbeen selected.
Ashort beepis emittedto acknowledgeabutton press.
ThemodulewillstorethecurrentDSPlevel,andwillreturn
tothislevelwhen theequipmentisswitched on, but
alwaysinthe off position.
6.2 Operation.
Switchontheequipment.
The LED will illuminate red or orange to indicate that the
noisecancellationisoff.Theunitwillflash/beeptoindicate
theDSPfilter levellastused.
6. Operation
6. Operation.

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NEDSP1061-KBD Operating Manual
Noise cancellation on/off: Press and release the
buttonand the LEDwill gooffindicating thatthenoise
cancellationis activated (greenin 4 levelmode).Ashort
beepwill acknowledge thekey press.
Changing the filter level: Holddownthebutton. The
ledwillflashthe filterlevel,andif the buttonisheldit will
stepthroughall the levels(4or8 dependingonwhich
mode you are in), audio beeps also indicate the filter
level.Releasethebuttontoselectalevel. This newlevel
willbestored inmemoryand willbethe defaultsetting
thenexttime theunitispowered up (alwayspowersup
withnoisecancellingoff).
6.3. Demonstration mode.
The NEDSP1061-KBD module features 2 preset
demonstrationmodes, andtheabilityto select4or8 filter
levels.Thesedemonstrate thenoisecancellationabilities
oftheNEDSP1061-KBDmoduleandthefilterlevelselect
mode. To listen to the demonstration modes, or change
thenumberofDSPlevelsitisnecessarytoputthemodule
intothe set upmode:
6.3.1Demonstration 1:
Holddownthebuttonandswitchontheequipment.Aftera
short time the unit will emit a 2 tone beep. Release the
button.Theunitis now indemonstrationmode1.
The module will switch the noise cancellation on for 1.5
seconds, then off for 1.5 seconds. It will then move onto
the next level and repeat this continuously through all 4
levels.
Thismode a particularlyeffective whenthe equipment is
justreceivingstatic, asitdemonstratesthe attenuationof
whitenoiseatallthe levels.
Alternatively tune the equipment into a good quality FM
speechbroadcast.Thisdemonstrationshowshowlittlethe
DSPaltersthe speech,atanyof thelevels.
6. Operation.

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NEDSP1061-KBD Operating Manual
6.3.2 Demonstration 2:
Followtheprocedurefor6.3.1.Waitforthesecond2tone
beep,thenreleasethe key.
Inthismode thefilterlevelis settolevel 3.
Thenoisecancellationis switchedonfor3seconds, then
offfor3seconds.Thisloopsuntiltheuserabortsthismode.
This is a good demonstration for listening noisy SSB
conversationsshowingthebeforeand after.
6.3.3 Filter Level Select:
Afterthe 3rd twotone beepthefilter levelpre-setsat
level4in 8levelmode, releasethebutton toselectthis
mode. Afterthefourth2 tonebeepthe moduleenters
thefilterlevelselectmode. Releasethebuttonafter
either the 4 or 8 beeps to select the desired level mode.
Themodulewillreturnto normal operationafterthis,or
holddownthe button untilthe2tone beepisheard.
Releasethebutton,after ashortdelaythe LEDwillflash
indicatingthestoredlevel, asduringthenormalswitch
on.
6.4 Notes about the noise reduction.
When using the module on level 4/4 or level 8/8 some
distortion maybeheard.Thisisquitenormalwhenlistening
toweaksignals withhighlevels ofnoisepresent.
6.5 Noise reduction levels.
6. Operation.

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NEDSP1061-KBD Operating Manual
Appendix A Yaesu FT-817.
Appendix A
Yaesu FT-817
This document should be read in conjunction with the
relevant Yaesu FT-817 technical supplement.
The bhi NEDSP1061-KBD module is inserted into the
audiopathofthetransceiver,atapointbeforethevolume
control. To access this point it is necessary to remove
the main unit.
Remove any fitted batteries or NiCad pack before
commencing installation.
Remove the top and bottom covers.
Remove the 5 main unit fixing screws.
Disconnect all connections - apart from the front unit
ribbon cable.
Hinge the main unit forward, over the front unit ribbon
cable.