BHI ANEM DSP Noise Eliminator

So, I’ve had this device for about two years now and have mentioned it to several people on the air, describing just how effective it is.

What is it? This is an active DSP audio noise eliminator filter manufactured by BHI Ltd.. As simply as possible, it wipes out background hash band noise. It isn’t a pulse noise eliminator like a noise blanker, though it will drastically soften the edge of pulse noise as well.

This is an AF (audio frequency stage) DSP unit. It plugs into the audio output of anything you want to feed through it and you in turn loop it’s output into the speaker or other destination audio feed of your choosing.

The unit has either 4 or 8 steps of increasing DSP elimination effects. In stronger conditions you can back it off easily so it isn’t as heavy handed on processing the signals, or in lousy conditions with weaker signals, you can really clamp it down for the maximum effect.

The best way to show you what this does is simply an mp3 file I created to demonstrate its effectiveness.

Here is a 40m SSB clip with the filter being toggled in and out

The clip was made with some high noise levels and relatively low signal levels at or below the noise peaks, using my vertical on 40m SSB.

The DSP setting was on maximum 8/8 so there is some minimal artifact on the audio signal and a very slight audio level drop. Keep in mind the completely annoying original signal. With the DSP engaged it would be easily possible to maintain a pleasant extended contact with any of the stations in the recording, vs only wanting a brief ‘in and out’ style contact before getting sick and tired of the noise level. A slight bit of the ‘under water’ artifact is much more tolerable.

These units are available in a few configurations from BHI Ltd.. They come in built-in modules designed to be hard wired into the audio circuit of a radio or to be built-in to the internal of a speaker cabinet. They also come in self contained powered speakers with the module included internally. Lastly and my personal favorite are the ‘universal’ inline modules. These allow you to use whatever source or speaker you choose by simply plugging in different inputs and outputs to the unit. It’s the most flexible option.

These modules aren’t cheap, but they are worth every cent if you like to spend a lot of time listening. is one source in the US for this product.

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13 February 2010