On the subject of BHI, I once had an ambitious project to build a switch box 
incorporating some SO2R functions plus two BHI DSP single channel units. Before 
I had finished wiring the unit (starting with just one BHI channel unit) my 
understanding of SO2R requirements grew to the point that I abandoned my build 
and went with a commercial MicroHam SO2R box. At this point I am no longer 
motivated to get a second BHI unit and deploy them. If anyone is inerested in 
buying the one I have, please email me directly and we can discuss a deal. To 
be clear: This is a unit for integration in other equipment, and not a 
standalone box ready to place on your desk. It does incorporate an AF power amp 
for driving a speaker, and the input may be driven from the radio speaker 
output.
73,
Erik K7TV

-----Original Message-----
From: elecraft-boun...@mailman.qth.net <elecraft-boun...@mailman.qth.net> On 
Behalf Of Erik Basilier
Sent: Saturday, January 12, 2019 1:11 PM
To: 'Walter Underwood' <wun...@wunderwood.org>; 'Elecraft Reflector Reflector' 
<elecraft@mailman.qth.net>
Subject: Re: [Elecraft] Query for new DSP features

The noise level at my QTH is not nearly as bad as many of you have. The K3 
S-meter tends to read around S4 on the background noise noise (SSB bandwidth, 
20m preamp off, atten off). When it comes to engaging NR, like many others I 
have in the past tended to crank up the aggressiveness etc and noted a loss of 
apparent volume on the wanted signal, and apparent loss of the higher frequency 
voice components. I have compensated by cranking up the volume and widening the 
passband (which helped little as the received station had insufficient boost of 
highs). I have admired the apparently better results from other DSP 
implementations such as BHI and other radios. Lately I have modified my 
approach to using the K3 DSP, and found much better results. For ssb I now have 
NR engaged full time and like it. The setting is the least aggressive possible: 
F1-1. I used to have the impression that this setting did little to help, but I 
have changed my opinion. The sound with this weak NR on now s
 eems very normal and comfortably intelligible. If I turn NR off, I can still 
read the signal, but it sounds harsh and tiring. I can't say the NR makes an 
unreadable signal readable, but it makes the copy more comfortable. My old 
brain seems to, slowly, adjust its own filtering to fit what is being heard, 
not just to focus on the wanted cw signal in a wider passband, but also when 
listening to voice when switching between NR on/off. This may be just my 
speculation, but subjectively, even with no radio involved, I seem to need an 
adjustment period also when listening to different adult voices, and especially 
when going between an adult voice and that of a small child. The existing K3 
DSP seems to be optimized based on objectively measurable criteria that are 
somewhat at odds with the strange workings of the human auditory system. 
Perhaps the addition of a tone control that alters the low/high tonal balance 
would be a helpful new resource for those who feel the NR makes signals
  sound weak or too bassy. The tone control setting could be automatically 
engaged with an emphasis on the highs when NR is engaged. It could also be 
helpful as a manual control for adapting to stations that have not adjusted 
their transmit equalizer to fit the operator's voice. Besides a low/high tilt, 
a peak/notch function might be helpful.
73,
Erik K7TV
e delivered to ebasil...@cox.net

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