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ANEM  Operating Manual

ANEM  Operating Manual

Page 13

3.4 Noise reduction levels.

4 or 8 levels of noise reduction are available. The amount
of noise and tone reduction is shown in the table below.

l

e

v

e

L

)

4

(

l

e

v

e

L

)

8

(

n

o

i

t

c

u

d

e

R

e

n

o

T

n

o

i

t

c

u

d

e

R

e

s

i

o

N

e

t

i

h

W

1

B

d

4

B

d

9

1

2

B

d

5

B

d

1

1

3

B

d

6

B

d

3

1

2

4

B

d

8

B

d

5

1

5

B

d

6

1

B

d

7

1

3

6

B

d

1

2

B

d

0

2

7

B

d

5

2

B

d

4

2

4

8

B

d

5

6

B

d

5

3

Table 2. Tone and noise reduction levels.

The column marked level (4) shows the noise and tone
reduction when operating the module with 4 levels, and
the level (8) column for 8 levels.

Holding down the DSP select button will continuously
change the DSP level. When the desired level has been
reached, release the button. The module will retain this
level until it is changed.

The 

ANEM

 is factory set up and ready for use. If you are

using the module in an application which requires
adjustment. For the optimum performance refer to section
4 for more information.

3.

Module Operation.

Page 16

Figure 11. Sensitivity.

0

0.5

1

1.5

2

2.5

0

50

100

150

200

Input voltage (mV)

Output power (W)

R

=  8

W

R

=  4

W

V

S

 = 16V

f = 1KHz

Section 4 contains information on adjusting the operation
of the 

ANEM

. The module is supplied factory set and under

normal circumstances no further adjustment is necessary.
The following information is for guidance only and any
adjusments to the DSP circuit should only be carried out
by those who have a technical understanding of what they
are doing.

3.

Module Operation.

Summary of Contents for ANEM

Page 1: ...g Manual DSP Noise Cancellation Products from bhi 1065 102D Issue E bhi bhi bhi bhi bhi Noise Away Page 28 bhi Ltd P O Box 318 Burgess Hill West Sussex RH15 9NR tel 44 0 845 217 9926 fax 44 0 845 217 9936 sales bhi ltd com www bhi ltd com bhi bhi bhi bhi bhi DSP Noise Cancellation Products from bhi DSP Noise Cancellation ...

Page 2: ...e audio level varies according to the volume setting of the equipment that the ANEM is being used with When you plug mono earphones into the Audio Out socket stereo earphones can be used with the bhi audio adapterADP S001 the SP PH Switch MUST BE set to the to PH position to prevent the possibility of injury to your ears Important Information Page 27 NCH2 Noise Cancelling Headphones These headphon...

Page 3: ... socket ADP P002 6 35mm plug 3 5mm mono socket ADP P003 3 5mm stereo plug 3 5mm mono socket ADP P004 Phono plug 3 5mm mono socket ADP P005 2 5mm mono plug 3 5mm mono socket ADP P006 2 5mm stereo plug 3 5mm mono socket ADP P007 6 35mm stereo plug 3 5mm stereo socket ADP P008 3 5mm stereo aircraft adapter ADP S001 3 5mm mono socket 3 5mm mono plug ADP S002 6 35mm socket 3 5mm mono plug ADP S003 6 35...

Page 4: ...amplified DSP in line module and simply connects in between the communications equipment and extension speaker It is suitable for a wide range of applications but is particularly useful for improving voice quality in amateur radio removing unwanted noise and interference to give much improved readability and speech intelligibility across all bands Page 25 6 3 NEIM1031MKII In line module 6 4 NEIM10...

Page 5: ... and illustrate how the signal is being processed 1 2 DSP Noise cancellation Page 24 6 Other bhi products 6 1 NES10 2 MK3 Noise Eliminating Speaker 6 Other bhi products Other noise cancellation products from bhi Visit www bhi ltd com for more information Features Fully adaptive noise cancellation 9 35dB 8 user selectable noise cancellation levels Mono earpiece socket Input sensitivity control Nois...

Page 6: ...ypass button DSP function button DSP function LED Figure 2 Connectors Figure 3 Controls Page 23 Start Increase input level Over load LED illuminates No Yes Reduce input so LED goes out Increase output level P1 Sufficient output volume Supply voltage 13 8 Vdc Input level too low Increase supply voltage Finish Yes Disconnect R6 see section 3 3 Over load LED illuminates Add additional amplification N...

Page 7: ...dspeaker then attach the strip of hook and eye fastener as shown below Page 22 Figure 17 Circuit modification for low power signal drive 4 4 Driving from a low signal source Cut the leg on this resistor 22W OUT 12 Agnd Agnd 9 10 Load V Audio Input R6 IN 11 Circuit modification Figure 16 Physical modification for low power signal drive Note Wiring and heatsink omitted for clarity 4 Technical Inform...

Page 8: ...nector is positive the lead with the white stripe is positive If you require a separate power supply then refer to section 6 4 for details The unit is now ready for use Figure 5 Block diagram 2 Module Overview Page 21 The ANEM requires a signal of 125mV rms or greater for optimum performance Signals lower than this may be used but the noise cancellation performance will decrease as the signal leve...

Page 9: ... performance The input sensitivity control has a range of 0 70mW 3W to provide 2W W output Under certain conditions RF breakthrough can sometimes occur To minimize this the input level P2 may need to be reduced or go to the FAQ page on the bhi website and download the FAQ on RF breakthrough Under certain conditions the DSP can create a small amount of noise you should not be able to hear this nois...

Page 10: ...in to demonstration mode 2 3 Module Operation Page 19 The input to the module is loaded at 22W to provide a dummy load to the preceding circuit This can be removed if required such as using the module in applications where the audio source is provided by a low level low power signal source More information on this can be found in section 3 3 in this operating manual If Vin is less than approx 13 8...

Page 11: ...ired level mode The module will return to normal operation after this The colour of the LED will indicate the mode of operation red for 4 level and orange for 8 level e d o m P S D s l e v e L 4 s l e v e L 8 F F O D E R E G N A R O N O N E E R G N E E R G Table 1 LED mode indication 3 Module Operation Page 18 4 1 Module Layout Figure 14 ANEM PCB and controls Input level set P2 Output level set P1...

Page 12: ...good demonstra tion of the before and after effects of remov ing the noise Demonstration 1 The module switches the noise cancellation on for 1 5 seconds then off for 1 5 seconds It will then move to the next level and repeat the process This mode is particularly effective at demonstrating the different DSP levels Alternatively pass a clean audio signal through the module to see hear how little the...

Page 13: ...continuously change the DSP level When the desired level has been reached release the button The module will retain this level until it is changed The ANEM is factory set up and ready for use If you are using the module in an application which requires adjustment For the optimum performance refer to section 4 for more information 3 Module Operation Page 16 Figure 11 Sensitivity 0 0 5 1 1 5 2 2 5 0...

Page 14: ...K 1 f PO W 5 0 PO W 0 1 PO W 0 2 0 6 0 9 0 3 1 V m Vi y t v i t i s n e s t u p n I 8W W W W W d a o l z H K 1 f PO W 5 0 PO W 0 1 PO W 0 2 1 8 7 1 1 0 8 1 V m B e s n o p s e r y c n e u q e r F B d 3 Po W 1 RL 8 W W W W W 0 5 0 0 3 4 z H d n o i t r o t s i D z H K 1 f PO R W 4 2 2 0 L 8 W W W W W PO R W 4 2 2 0 L 4 W W W W W 8 0 8 0 Ri e c n a t s i s e r t u p n I 1 2 2 2 3 2 W W W W W Gv n i ...

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