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Support & FAQs

Have a question or need technical support?

If you have any questions about our noise cancelling products or require some support please don’t hesitate to contact us.  Also, have a look at bhi's most commonly asked questions, as they may help you...

Q. Do bhi DSP noise cancelling products work with SSB transmissions?

A. Yes, they work with SSB transmissions and on all other radio bands as the DSP noise cancelling works with any signal that contains speech and is able to differentiate the speech from the noise.

Q. What adjustments do I need to make during use on the NES10-2MK4?

A. The volume control on the top of the speaker should be set at a quarter turn up from the minimum. You can make fine adjustments to this depending on the volume of the normal listening level from your radio in bypass mode. Once the NES10-2 is configured to your own personal settings, the only adjustments needed are to select the suitable filter level for the current operating conditions (see user guide for details).

Q. Can I connect more than one radio to my bhi unit?

A. Yes, you can connect more than one radio to your bhi unit. There are several ways to do this depending on your set-up. Read our in-depth blog post about connecting different radios to your bhi unit to find out the best way to do this.

Q. I sometimes hear some audio artefacts/waterfall sounds when listening to the unit?

A. If you listen to bhi DSP noise cancelling products with no audio signal present or a very low speech signal with high noise present, you may hear some DSP processing noise. This is normal and part of the DSP doing its work trying to process the signal. If you lower the filter level, then the audio artefacts will be less, but the noise will be louder. It is a trade-off in this instance. 

Q. Can I use a switch mode power supply with the speakers and in-line units?

A. Yes, you can use a switched mode power supply, but just be aware that the cheaper, lower cost switched mode power supplies have been known to generate noise and cause interference.

Q. When transmitting, the signal can be heard through the speaker on the radio or in my headphones?

A: bhi DSP noise cancelling products have plenty of RF protection inside and are not causing the issue. The two main reasons are:

  • A poorly matched antenna which results in RF being reflected back into the radio room.
  • A difference in ground currents between pieces of equipment.  
Firstly check that all your coax connections are secure and that your antenna system is matched up as best it can be at the antenna feed point. Also, make sure that all your cables are routed as far away from the RF as possible. Having an elevated SWR on the coax leading to your transceiver can cause transmit audio to be present. Try to match your antenna system up at the antenna feed point, and you shouldn’t hear any audio on transmit. If this is not possible due to your setup and location, then the following should help in eliminating this issue. 
  1. Try using on a separate DC power supply to power your bhi unit. We sell a number of different power supplies to suit our various DSP noise cancelling products
  2. Use one of our new bhi GroundBreaker audio isolation units to get rid of the feedback. This new audio product totally isolates the grounds of your ancillary equipment from those of the radio system. It is easy to install and simply plugs in between your radio and ancillary audio equipment. There are a number of versions to suit most connections and impedances.
  3. Look at both help sheets below for a solution. 

Additional Help

bhi has published the following documents to answer any further questions you may have.

RF Breakthrough/Earth Loop FAQ
RF breakthrough Help Sheet 1
RF breakthrough - power supply Help Sheet 2