[Elecraft] K3 Noise Reduction..revisited

[Trevor Smithers]

As far as I'm aware there are two companies that produce this technology for the amateur 
market, BHI in the UK and Michels-Engineering in Germany. The german unit is designed 
specifically for the extraction of the speech waveform when surrounded by noise. BHI is similar 
but works with cw as well.

Here are a couple of links to audio samples of both units in operation
http://www.ing-michels.de/audio_demonstrations.html
http://www.radio.bhinstrumentation.co.uk/html/demonstration.html

There is a downside to using these units in that they only work with a mono input so you loose the 
binaural function. To get around this I purchased two of the internal modules (DX21) from 
Michels-Engineering and wired them to each stereo channel. This allows independent control of 
the noise reduction in each ear and retains the AFX/binaural function.

73
Trevor  G0KTN