DSP Noise Cancellation bhi Ltd 22 Woolven Close Burgess Hill West Sussex RH15 9RR tel: +44 (0)845 217 9926 fax: +44 (0)845 217 9936 sales@bhi-ltd.co.uk www.bhi-ltd.co.
Important Information 6.5 Other products. NCH Noise Cancelling Headphones BBRP Banner Badge Get the message across Easy to program using push buttons on back: no cords, no wires, no software needed. Enter your message and watch it scroll across. These headphones feed an inverted copy of the ambient noise to cancel it out. The headphones effectively remove noise such as blower noise, ambient noise, jet engine noise or music from another room.
Contents 1042 Switch box Allows connection of up to 6 pieces of equipment to one bhi noise elimination speaker or any other extension speaker. (Includes 2 free ALD001 3.5mm audio leads) 6. Other bhi products. 6.4 Audio Adapters and Accessories. Power adapters: 1030-UKPA 12V DC UK power adapter 1030-EUPA 12 VDC European adapter 1030-VEPL Fused vehicle power adapter Audio leads: ALD-001 1.2m 3.5mm - 3.5mm mono lead ALD-002 2.5m 3.5mm - 3.5mm mono lead ALD-003 phono -phono plug ALD-004 3.
6.3 The ANEM is a compact, easy to use amplified DSP inline 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. 1. Introduction. The ANEM is suited to customers who prefer simple controls and operation.
6. Other bhi products Features: 6.1 NES10-2 MKII Noise Eliminating speaker. 6. Other bhi products. DSP noise cancellation built into a compact speaker unit. the unit provides an easy to install solution to noise reduction Features: • Fully adaptive noise cancellation 9 -35dB • 8 user selectable noise cancellation levels • Mono earpiece socket • Input sensitivity control • Noise cancellation On/Off switch • LED indication of power and noise cancellation • 12-24VDC operation • On/Off audio bypass switch.
Increase supply voltage No Yes DSP function button DSP function LED Reduce input level Finish Yes Audio out? Increase output level P1 No Increase input signal P2 Yes No SP Speaker/ Headphone switch Figure 3. Controls Page 6 Input signal Start Power on/off bypass button Overload LED on Yes Apply audio signal Figure 2. Connectors No Audio In (from equipment) ANEM Operating Manual ANEM Operating Manual Page 23 5. Troubleshooting.
4.4 Driving from a low signal source. 2.3 The input to the module has a low impedance. This is to provide correct loading to any power circuits driving it. If the module needs to be driven from a low power signal then it must be modified in the following manner. The case must first be removed, as described in section 4.2. Note: Wiring and heatsink omitted for clarity. The ANEM can be used on the bench, or attached to your loudspeaker using the velcro strips supplied.
+ Audio Source Audio In Audio Out ANEM - 2. Module Overview. Figure 5. Block diagram Speaker or headphones Power Connect the 3.5mm mono lead supplied to the extension speaker socket of your equipment and the audio in socket on the ANEM. Connect a loudspeaker or headphones to the audio out socket on the ANEM. Warning: The 3.5mm mono Audio Out socket provides variable audio output for an external speaker (4 ohm - 8 ohm impedance) or earphones.
4.3 Module setup. The module is factory set but both the input and output levels are adjustable on the module. This allows easy integration into target systems. If you need to adjust the module follow the instructions below. 4.3.1 Overview. To obtain the best results from the noise reduction the module should be set up to give optimum 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.
3.2 Set up. The following flow chart shows the functions of the DSP button. Power up DSP button pressed Turning the potentiometers clock wise will decrease the levels. These potentiometers do not have end stops, so it is possible to set them in a position where the audio will be lost. 2 tone sound Releasing the DSP button at this point the module goes in to demonstration mode 1 DSP button pressed No Demonstration 1 Yes 3. Module Operation.
4. Technical Information. 4.1 Module Layout. In order to access the printed circuit board the case needs to be removed. To do this, ensure the module is Off. Press and hold the DSP level button. Turn on the module and a 2 tone beep will be heard indicating that the module is in the set up mode. Releasing the button after the first 2 tone beep will enter demonstration mode 1. Figure 13. ANEM case dis-assembly detail. The following diagram shows the internal layout of the ANEM printed circuit board.
3.3 Demonstration modes. Start Start Noise cancellation On Noise cancellation On Wait 3 Seconds Wait 1.5 Seconds Noise cancellation off Noise cancellation off Wait 3 Seconds Increase DSP noise cancellation level DSP button pressed? Yes 3. Module Operation. 2 tone beep Figure 8. Demonstration modes. No Highest Level? 4. Technical Information. No This page is left blank Yes Normal operation Normal operation Demonstration 1. The module switches the noise cancellation on for 1.
3.4 Figure 11. Sensitivity. Output power (W) VS = 16V f = 1KHz RL = 8W 1.5 L evel (4) 1 RL = 4W 0.5 1 0 0 50 100 150 200 2 Input voltage (mV) 3 3. Module Operation. 4 L evel (8) Tone Reduction White Noise Reduction 1 4dB 9dB 2 5dB 11dB 3 6dB 13dB 4 8dB 15dB 5 16dB 17dB 6 21dB 20dB 7 25dB 24dB 8 65dB 35dB Table 2. Tone and noise reduction levels. Section 4 contains information on adjusting the operation of the ANEM.
3.5 Electrical characteristics. Figure 9. Frequency response 5 ELECTRICAL CHARACTERISTICS i (Vs=16V, Tamb= 25 C unless otherwise stated) 0 0 Symbol Parameter Test Conditions Min. Typ. Max. Units 12 16 18 V Vs Supply voltage Iqs Quiescent current V s = 12V V s = 16V V s = 18V 4.6 6.8 7.
