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K3: noise reduction performance

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K2QI

K3: noise reduction performance

Hello Elecrafters,

Regarding the issue of NR, I know this can be a touchy subject and most will
say its very subjective. This post isn't intended as a complaint or
criticism. Instead, I hope through constructive discussions, more
improvements to the K3's NR performance will be realized. I'd like to begin
by saying that Lyle and crew have a done a fantastic job to date with the
K3's NR. I've had the privilege of watching the K3's NR function improve
over time. The boys at Aptos should really be commended for listening to
their customers.

With that said, the recent CQSS has made me realize that there is still room
for improvement. During the SS, I used NR extensively in combination with
RF gain and filter hi-cut/lo-cut/shift settings. NR when used in
combination with the aforementioned K3 adjustments can and does work well.
The problem that I believe remains however is the algorithm used still
seems too broad in its rejection calculations; what I mean is that SSB
settings (i.e. F5-1 and higher) don't seem to be selective enough to reduce
noise while allowing speech patterns to remain unaffected. In other words,
the DSP sounds like its reducing everything within its passband. To my
ears, the NR doesn't seem to make speech "pop out" quite as effectively has
other NR implementations. This can be seen by a not-so-subtle reduction in
speech volume whenever the NR is turned on. The NR behavior is consistent
regardless of AGC slope or threshold settings.

Below are several links to audio recordings of a product I used to own. It
is called the BHI ANEM (Mk. II). Sadly, I sold it after getting the K3. I
should have hung on to it as it has become my benchmark for NR performance.

These are some sample recordings of the ANEM being turned on and off. These
recordings are found on W4RT's website

20 m SSB <http://www.w4rt.com/BHI/20Mband-ssb.wav>
80 m SSB <http://www.w4rt.com/BHI/80conv-ssb.wav>
80 m SSB <http://www.w4rt.com/BHI/80Mconv2-ssb.wav>

I've also compared the K3's NR performance to that of the Icom 756 Pro 3
which has similar NR reduction properties - albeit not as effective - as the
ANEM.

Perhaps I am being subjective or overly critical, but one thing you can
easily notice with the ANEM recordings is that speech volume doesn't get as
affected as the K3s. This is really surprising to me as the NR for the ANEM
is AF rather than IF like what's used in our radios. This leads me to
believe that the ANEM's NR algorithms are more effective in reducing
background noise while leaving speech unaffected.

What do you guys think?

Sorry for the long email. Many thanks in advance for your ideas/suggestions.
<http://www.w4rt.com/BHI/20Mband-ssb.wav>
--
73 de James K2QI
President UNARC/4U1UN
______________________________________________________________
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Post: mailto:[hidden email]

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--... ...-- -.. . .--- .- -- . ...

Johnny Siu

Re: K3: noise reduction performance

Hi James

I concur with your observations and let us have an open minded discussion here.

Johnny vr2xmc

Sent from my iPhone 4

"James Sarte (K2QI)" <[hidden email]> 於 2010年11月27日下午8:16 寫道：

> Hello Elecrafters,
>
> Regarding the issue of NR, I know this can be a touchy subject and most will
> say its very subjective. This post isn't intended as a complaint or
> criticism. Instead, I hope through constructive discussions, more
> improvements to the K3's NR performance will be realized. I'd like to begin
> by saying that Lyle and crew have a done a fantastic job to date with the
> K3's NR. I've had the privilege of watching the K3's NR function improve
> over time. The boys at Aptos should really be commended for listening to
> their customers.
>
> With that said, the recent CQSS has made me realize that there is still room
> for improvement. During the SS, I used NR extensively in combination with
> RF gain and filter hi-cut/lo-cut/shift settings. NR when used in
> combination with the aforementioned K3 adjustments can and does work well.
> The problem that I believe remains however is the algorithm used still
> seems too broad in its rejection calculations; what I mean is that SSB
> settings (i.e. F5-1 and higher) don't seem to be selective enough to reduce
> noise while allowing speech patterns to remain unaffected. In other words,
> the DSP sounds like its reducing everything within its passband. To my
> ears, the NR doesn't seem to make speech "pop out" quite as effectively has
> other NR implementations. This can be seen by a not-so-subtle reduction in
> speech volume whenever the NR is turned on. The NR behavior is consistent
> regardless of AGC slope or threshold settings.
>
> Below are several links to audio recordings of a product I used to own. It
> is called the BHI ANEM (Mk. II). Sadly, I sold it after getting the K3. I
> should have hung on to it as it has become my benchmark for NR performance.
>
> These are some sample recordings of the ANEM being turned on and off. These
> recordings are found on W4RT's website
>
> 20 m SSB <http://www.w4rt.com/BHI/20Mband-ssb.wav>
> 80 m SSB <http://www.w4rt.com/BHI/80conv-ssb.wav>
> 80 m SSB <http://www.w4rt.com/BHI/80Mconv2-ssb.wav>
>
> I've also compared the K3's NR performance to that of the Icom 756 Pro 3
> which has similar NR reduction properties - albeit not as effective - as the
> ANEM.
>
> Perhaps I am being subjective or overly critical, but one thing you can
> easily notice with the ANEM recordings is that speech volume doesn't get as
> affected as the K3s. This is really surprising to me as the NR for the ANEM
> is AF rather than IF like what's used in our radios. This leads me to
> believe that the ANEM's NR algorithms are more effective in reducing
> background noise while leaving speech unaffected.
>
> What do you guys think?
>
> Sorry for the long email. Many thanks in advance for your ideas/suggestions.
> <http://www.w4rt.com/BHI/20Mband-ssb.wav>
> --
> 73 de James K2QI
> President UNARC/4U1UN
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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Please help support this email list: http://www.qsl.net/donate.html

Geoffrey Mackenzie-Kennedy

Re: K3: noise reduction performance

In reply to this post by K2QI

Hello James,

I use a BHI ANEM Mk II with my K2, and get similar results.

My K2 does not have the Noise Blanker installed nor the DSP, one reason
being that man-made noise at this quiet rural location was never a problem.
But, about two years ago some new neighbours arrived armed with some device
that generates RFI, which I think is something used in their kitchen, maybe
a blender - hence the purchase of the BHI which solved this noise problem
when using the K2.

The NR in my Perseus SDR performs well, but not quite as well as the BHI -
but that is an impression.

The usual disclaimers apply.

73,

Geoff
GM4ESD

On November 27, 2010, at 12:16 PM, James Sarte (K2QI) wrote:

<snip>

> Below are several links to audio recordings of a product I used to own.
> It
> is called the BHI ANEM (Mk. II). Sadly, I sold it after getting the K3. I
> should have hung on to it as it has become my benchmark for NR
> performance.
>
> These are some sample recordings of the ANEM being turned on and off.
> These
> recordings are found on W4RT's website
>
> 20 m SSB <http://www.w4rt.com/BHI/20Mband-ssb.wav>
> 80 m SSB <http://www.w4rt.com/BHI/80conv-ssb.wav>
> 80 m SSB <http://www.w4rt.com/BHI/80Mconv2-ssb.wav>
>
> I've also compared the K3's NR performance to that of the Icom 756 Pro 3
> which has similar NR reduction properties - albeit not as effective - as
> the
> ANEM.
>
> Perhaps I am being subjective or overly critical, but one thing you can
> easily notice with the ANEM recordings is that speech volume doesn't get
> as
> affected as the K3s. This is really surprising to me as the NR for the
> ANEM
> is AF rather than IF like what's used in our radios. This leads me to
> believe that the ANEM's NR algorithms are more effective in reducing
> background noise while leaving speech unaffected.

k6rb

Re: K3: noise reduction performance

In reply to this post by K2QI

I'm still getting my sea legs on the K3 but NR seems to work really great
on CW but on SSB, I can't use it. With it on, regardless of setting, it
makes the channel sound "watery" (for lack of a better term). I have two
K3s, and both sound alike on phone with NR invoked. Maybe I don't have
them adjusted properly, but I find the sound very disconcerting.

Rob K6RB

> Hello Elecrafters,
>
> Regarding the issue of NR, I know this can be a touchy subject and most
> will
> say its very subjective. This post isn't intended as a complaint or
> criticism. Instead, I hope through constructive discussions, more
> improvements to the K3's NR performance will be realized. I'd like to
> begin
> by saying that Lyle and crew have a done a fantastic job to date with the
> K3's NR. I've had the privilege of watching the K3's NR function improve
> over time. The boys at Aptos should really be commended for listening to
> their customers.
>
> With that said, the recent CQSS has made me realize that there is still
> room
> for improvement. During the SS, I used NR extensively in combination with
> RF gain and filter hi-cut/lo-cut/shift settings. NR when used in
> combination with the aforementioned K3 adjustments can and does work well.
> The problem that I believe remains however is the algorithm used still
> seems too broad in its rejection calculations; what I mean is that SSB
> settings (i.e. F5-1 and higher) don't seem to be selective enough to
> reduce
> noise while allowing speech patterns to remain unaffected. In other
> words,
> the DSP sounds like its reducing everything within its passband. To my
> ears, the NR doesn't seem to make speech "pop out" quite as effectively
> has
> other NR implementations. This can be seen by a not-so-subtle reduction
> in
> speech volume whenever the NR is turned on. The NR behavior is
> consistent
> regardless of AGC slope or threshold settings.
>
> Below are several links to audio recordings of a product I used to own.
> It
> is called the BHI ANEM (Mk. II). Sadly, I sold it after getting the K3. I
> should have hung on to it as it has become my benchmark for NR
> performance.
>
> These are some sample recordings of the ANEM being turned on and off.
> These
> recordings are found on W4RT's website
>
> 20 m SSB <http://www.w4rt.com/BHI/20Mband-ssb.wav>
> 80 m SSB <http://www.w4rt.com/BHI/80conv-ssb.wav>
> 80 m SSB <http://www.w4rt.com/BHI/80Mconv2-ssb.wav>
>
> I've also compared the K3's NR performance to that of the Icom 756 Pro 3
> which has similar NR reduction properties - albeit not as effective - as
> the
> ANEM.
>
> Perhaps I am being subjective or overly critical, but one thing you can
> easily notice with the ANEM recordings is that speech volume doesn't get
> as
> affected as the K3s. This is really surprising to me as the NR for the
> ANEM
> is AF rather than IF like what's used in our radios. This leads me to
> believe that the ANEM's NR algorithms are more effective in reducing
> background noise while leaving speech unaffected.
>
> What do you guys think?
>
> Sorry for the long email. Many thanks in advance for your
> ideas/suggestions.
> <http://www.w4rt.com/BHI/20Mband-ssb.wav>
> --
> 73 de James K2QI
> President UNARC/4U1UN
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>

AC7AC

Re: K3: noise reduction performance

In reply to this post by Johnny Siu

CONTENTS DELETED

The author has deleted this message.

Guy, K2AV

Re: K3: noise reduction performance

In reply to this post by K2QI

Hi James,

I'd have to say that your post and the links to what you consider
improvement firmly make the case for how subjective this is. Some folks
simply cannot stand to listen to the "warbling" effect caused by the NR
algorithm moving around the center of the "passband" to match the speech
centers and reject the bands with noise only. What you are asking for is
what they can't stand... K2 NR has that sound.

The great problem of noise reduction design is the difference in the
individual GOALS of using NR. For some, this is to remove the IRRITANT of
noise, and for others to remove the UNINTELLIGIBILITY caused by noise. The
latter goal produces different methods than the former. The former is
doomed from the start because people's hearing range differs with SOME wide
hearers intensely annoyed by high frequency noise, others used to listening
to 80 meter QRN in the summer may want reduction with ZERO loss of weak
signal, and others are very ANNOYED by reduction ARTIFACTS.

For me it's just like anything else going on in firmware, I hope Wayne works
on the stuff I want first, and that he keeps working on stuff. My list does
not have NR improvement near the top. That's because there is a limit to
what NR can do that does not mask very weak signals when it's on. NB is
another story, and the t3-7 or t2-7 with sharp skirts effect on key clicks
has allowed me to copy many signals where copy was not otherwise possible.

I will have to agree with you on the volume issues, because I always NOTICE
it. BUT, that falls in the IRRITANT category, not the INTELLIGIBILITY
category. So I walk on by and wait for Lyle to figure out how to nullify
plasma noise. I'm not holding my breath, but there really is a part of me
that thinks he might.

BTW, I turn NR *OFF* in contests, period. There is not a single NR setting
that I cannot demonstrate a very weak signal loss, that occurs where the NR
starts to blend with the noise. My ears, and everyone else's, will do a
better job than the NR at that point. And particularly, now that we have
APF for CW, hearing that tiny peep is all the clue I need to zero in the APF
and get it out of the noise. NR on, and I don't even know it is there.

I don't think anyone really knows (federal court worthy peer-reviewed
scientific proof) how our ears hear discrete signals that are blending in
the noise, but I have a suspicion. How many reading this have been driving
home after a weekend CW contest and hear CW in the road noise? Our brains
have some kind of heuristic anticipatory mechanism. It's the very one that
allows me to copy the "QRP" in DL5QQ/QRP and struggle with the rest to my
utter annoyance as he sends the /QRP over and over again. (Talk about
irritating.)

However it works, it is more effective than anything electronic by some
orders of magnitude, and NR strips out what makes it work at the very point
that the brain/ear makes the greatest difference. Others may disagree in a
contest, just because they want to operate in comfort. That's fine by me,
just don't apply for a seat in our WFO NY4A efforts, where our getting ALL
the very weakest stuff is our score differential over the competion. If you
work 2K+ contacts on 40m in the ARRL DX CW, you can be guaranteed that three
or four or five HUNDRED of those contacts are too-far-away QRP, radio-trash
crap antenna weak, or at the very edge of propagation where they hear your
1.5 kW above their noise, but their 100w and built-in -12 dB disadvantage
puts them firmly IN the noise. Turning on NR in a CW contest can cost you
hundreds of QSO's at a competitive station. ANYONE can work loud and medium
stations. Try hard and most can work moderately weak. The last layer is
only solved by the human brain, and the SOUND of it is irritating and
tiring.

Our in-the-noise hearing is likely honed by millions of years hearing the
movement or breathing of a sabre-tooth tiger before it could spring. In
that environment the "false positive" of my hearing CW in the road noise,
e.g. hearing a sabre-tooth when there really wasn't one, was easily
tolerated in favor of having one or two steps moving away before a real
tiger charged.

What a noise reduction designer is up against is nature honing something
absolutely essential for millions of years, vs analysis in a very limited
computing environment. And up against a wild variation in customer taste
and tolerance for things audio.

I'd say that if a box makes something sound like you like it, don't toss it
until the new thing demonstrates what you like. There is no natural law
that states that superior results for all problems will always be obtained
processing at IF in a K3. They're doing it there because it fits in the
scheme of all they're trying to do, and the means is commercially limited.
On whole they've succeeded brilliantly, but there simply MUST be SOME things
they can't do as well that way.

73, Guy.

On Sat, Nov 27, 2010 at 7:16 AM, James Sarte (K2QI) <[hidden email]>wrote:

> Hello Elecrafters,
>
> Regarding the issue of NR, I know this can be a touchy subject and most
> will
> say its very subjective. This post isn't intended as a complaint or
> criticism. Instead, I hope through constructive discussions, more
> improvements to the K3's NR performance will be realized. I'd like to begin
> by saying that Lyle and crew have a done a fantastic job to date with the
> K3's NR. I've had the privilege of watching the K3's NR function improve
> over time. The boys at Aptos should really be commended for listening to
> their customers.
>
> With that said, the recent CQSS has made me realize that there is still
> room
> for improvement. During the SS, I used NR extensively in combination with
> RF gain and filter hi-cut/lo-cut/shift settings. NR when used in
> combination with the aforementioned K3 adjustments can and does work well.
> The problem that I believe remains however is the algorithm used still
> seems too broad in its rejection calculations; what I mean is that SSB
> settings (i.e. F5-1 and higher) don't seem to be selective enough to reduce
> noise while allowing speech patterns to remain unaffected. In other words,
> the DSP sounds like its reducing everything within its passband. To my
> ears, the NR doesn't seem to make speech "pop out" quite as effectively has
> other NR implementations. This can be seen by a not-so-subtle reduction in
> speech volume whenever the NR is turned on. The NR behavior is consistent
> regardless of AGC slope or threshold settings.
>
> Below are several links to audio recordings of a product I used to own. It
> is called the BHI ANEM (Mk. II). Sadly, I sold it after getting the K3. I
> should have hung on to it as it has become my benchmark for NR performance.
>
> These are some sample recordings of the ANEM being turned on and off.
> These
> recordings are found on W4RT's website
>
> 20 m SSB <http://www.w4rt.com/BHI/20Mband-ssb.wav>
> 80 m SSB <http://www.w4rt.com/BHI/80conv-ssb.wav>
> 80 m SSB <http://www.w4rt.com/BHI/80Mconv2-ssb.wav>
>
> I've also compared the K3's NR performance to that of the Icom 756 Pro 3
> which has similar NR reduction properties - albeit not as effective - as
> the
> ANEM.
>
> Perhaps I am being subjective or overly critical, but one thing you can
> easily notice with the ANEM recordings is that speech volume doesn't get as
> affected as the K3s. This is really surprising to me as the NR for the
> ANEM
> is AF rather than IF like what's used in our radios. This leads me to
> believe that the ANEM's NR algorithms are more effective in reducing
> background noise while leaving speech unaffected.
>
> What do you guys think?
>
> Sorry for the long email. Many thanks in advance for your
> ideas/suggestions.
> <http://www.w4rt.com/BHI/20Mband-ssb.wav>
> --
> 73 de James K2QI
> President UNARC/4U1UN
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

Dave Perry N4QS

Re: K3: noise reduction performance

In reply to this post by k6rb

Rob,

NR can be very effective on SSB depending on conditions, but it takes some
careful adjustments. Try F7 through F8 settings and I also have to adjust
Hi/Lo settings to improve readability of the audio. You can often reduce
the watery effect and greatly improve overall readability on a noisy night.
Doesn't work all the time -- depending on QRN conditions. I would say about
80% of the time I can achieve a noticeable improvement using NR on SSB when
the noise is high. You're not trying to achieve best fidelity with this
technique -- just improved readability.

Dave, N4QS

----- Original Message -----
From: <[hidden email]>
To: "James Sarte (K2QI)" <[hidden email]>
Cc: "Elecraft" <[hidden email]>
Sent: Saturday, November 27, 2010 10:07 AM
Subject: Re: [Elecraft] K3: noise reduction performance

> I'm still getting my sea legs on the K3 but NR seems to work really great
> on CW but on SSB, I can't use it. With it on, regardless of setting, it
> makes the channel sound "watery" (for lack of a better term). I have two
> K3s, and both sound alike on phone with NR invoked. Maybe I don't have
> them adjusted properly, but I find the sound very disconcerting.
>
> Rob K6RB
>
>> Hello Elecrafters,
>>
>> Regarding the issue of NR, I know this can be a touchy subject and most
>> will
>> say its very subjective. This post isn't intended as a complaint or
>> criticism. Instead, I hope through constructive discussions, more
>> improvements to the K3's NR performance will be realized. I'd like to
>> begin
>> by saying that Lyle and crew have a done a fantastic job to date with the
>> K3's NR. I've had the privilege of watching the K3's NR function improve
>> over time. The boys at Aptos should really be commended for listening to
>> their customers.
>>
>> With that said, the recent CQSS has made me realize that there is still
>> room
>> for improvement. During the SS, I used NR extensively in combination
>> with
>> RF gain and filter hi-cut/lo-cut/shift settings. NR when used in
>> combination with the aforementioned K3 adjustments can and does work
>> well.
>> The problem that I believe remains however is the algorithm used still
>> seems too broad in its rejection calculations; what I mean is that SSB
>> settings (i.e. F5-1 and higher) don't seem to be selective enough to
>> reduce
>> noise while allowing speech patterns to remain unaffected. In other
>> words,
>> the DSP sounds like its reducing everything within its passband. To my
>> ears, the NR doesn't seem to make speech "pop out" quite as effectively
>> has
>> other NR implementations. This can be seen by a not-so-subtle reduction
>> in
>> speech volume whenever the NR is turned on. The NR behavior is
>> consistent
>> regardless of AGC slope or threshold settings.
>>
>> Below are several links to audio recordings of a product I used to own.
>> It
>> is called the BHI ANEM (Mk. II). Sadly, I sold it after getting the K3.
>> I
>> should have hung on to it as it has become my benchmark for NR
>> performance.
>>
>> These are some sample recordings of the ANEM being turned on and off.
>> These
>> recordings are found on W4RT's website
>>
>> 20 m SSB <http://www.w4rt.com/BHI/20Mband-ssb.wav>
>> 80 m SSB <http://www.w4rt.com/BHI/80conv-ssb.wav>
>> 80 m SSB <http://www.w4rt.com/BHI/80Mconv2-ssb.wav>
>>
>> I've also compared the K3's NR performance to that of the Icom 756 Pro 3
>> which has similar NR reduction properties - albeit not as effective - as
>> the
>> ANEM.
>>
>> Perhaps I am being subjective or overly critical, but one thing you can
>> easily notice with the ANEM recordings is that speech volume doesn't get
>> as
>> affected as the K3s. This is really surprising to me as the NR for the
>> ANEM
>> is AF rather than IF like what's used in our radios. This leads me to
>> believe that the ANEM's NR algorithms are more effective in reducing
>> background noise while leaving speech unaffected.
>>
>> What do you guys think?
>>
>> Sorry for the long email. Many thanks in advance for your
>> ideas/suggestions.
>> <http://www.w4rt.com/BHI/20Mband-ssb.wav>
>> --
>> 73 de James K2QI
>> President UNARC/4U1UN
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
>>
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

N2TK

Re: K3: noise reduction performance

In reply to this post by K2QI

Hi James,
I know some don't agree with me on this, but I concur what you find. I know
it is being picky. But I still like the Icom's DSP set to a very low level.
It is not very aggressive at that setting and reduces the background noise
to make it less tiring on SSB. And yes the SSB NR has significantly improved
over time. Every year at Dayton I ask for something less aggressive than
F5-1and that doesn't reduce the audio.
Maybe I am not setting up the K3 properly that it seems to work for others?
I know I have made enough goofs with operating this rig and others.

I really do like the NR on CW.

And did I say how happy I am with the APF?

73,
N2TK, Tony
#311
#1435

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of James Sarte (K2QI)
Sent: Saturday, November 27, 2010 7:16 AM
To: Elecraft
Subject: [Elecraft] K3: noise reduction performance

Hello Elecrafters,

Regarding the issue of NR, I know this can be a touchy subject and most will
say its very subjective. This post isn't intended as a complaint or
criticism. Instead, I hope through constructive discussions, more
improvements to the K3's NR performance will be realized. I'd like to begin
by saying that Lyle and crew have a done a fantastic job to date with the
K3's NR. I've had the privilege of watching the K3's NR function improve
over time. The boys at Aptos should really be commended for listening to
their customers.

With that said, the recent CQSS has made me realize that there is still room
for improvement. During the SS, I used NR extensively in combination with
RF gain and filter hi-cut/lo-cut/shift settings. NR when used in
combination with the aforementioned K3 adjustments can and does work well.
The problem that I believe remains however is the algorithm used still
seems too broad in its rejection calculations; what I mean is that SSB
settings (i.e. F5-1 and higher) don't seem to be selective enough to reduce
noise while allowing speech patterns to remain unaffected. In other words,
the DSP sounds like its reducing everything within its passband. To my
ears, the NR doesn't seem to make speech "pop out" quite as effectively has
other NR implementations. This can be seen by a not-so-subtle reduction in
speech volume whenever the NR is turned on. The NR behavior is consistent
regardless of AGC slope or threshold settings.

Below are several links to audio recordings of a product I used to own. It
is called the BHI ANEM (Mk. II). Sadly, I sold it after getting the K3. I
should have hung on to it as it has become my benchmark for NR performance.

These are some sample recordings of the ANEM being turned on and off. These
recordings are found on W4RT's website

20 m SSB <http://www.w4rt.com/BHI/20Mband-ssb.wav>
80 m SSB <http://www.w4rt.com/BHI/80conv-ssb.wav>
80 m SSB <http://www.w4rt.com/BHI/80Mconv2-ssb.wav>

I've also compared the K3's NR performance to that of the Icom 756 Pro 3
which has similar NR reduction properties - albeit not as effective - as the
ANEM.

Perhaps I am being subjective or overly critical, but one thing you can
easily notice with the ANEM recordings is that speech volume doesn't get as
affected as the K3s. This is really surprising to me as the NR for the ANEM
is AF rather than IF like what's used in our radios. This leads me to
believe that the ANEM's NR algorithms are more effective in reducing
background noise while leaving speech unaffected.

What do you guys think?

Sorry for the long email. Many thanks in advance for your ideas/suggestions.
<http://www.w4rt.com/BHI/20Mband-ssb.wav>
--
73 de James K2QI
President UNARC/4U1UN
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Johnny Siu

K3: noise reduction performance

In reply to this post by AC7AC

Yes, there have been improvements in the DSP of K3. One of the reasons of
selling my K3#46 was the artifacts of the DSP. I have recently acquired another
K3 in the second hand market with later production. I do notice there have been
improvements.

I am mainly a phone operator with ocassional digital mode at PACTOR 3.
Among the 4 x 8 =32 selections in the NR, I find it difficult to get one
effective among the 32 choices. From my past and present experience of my Icom
families, I know what are the limitations of NR.

I am looking for a simple but effective NR which can cut 'some of the noise'
with least artifacts, and also easy to work with. At this moment, I still
prefer the NR in my Icoms. Having said that, I know the smart guys
in Elecraft will keep on improving the K3 so that hopefully we will have better
performance in later version of firmware.
cheers,

Johnny VR2XMC

----- 郵件原件 ----
寄件人﹕ Ron D'Eau Claire <[hidden email]>
收件人﹕ Elecraft <[hidden email]>
傳送日期﹕ 2010/11/28 (日) 12:14:47 AM
主題： Re: [Elecraft] K3: noise reduction performance

This is a good example of just how subjective "improvement" can be.

Sure, the "hash" is gone, but it's replaced by the "underwater" warbling
sound so common with highly processed audio.

Personally, I find that warbling variation in the audio far less pleasant
than the noise.

Ron AC7AC

-----Original Message-----
>
> Below are several links to audio recordings of a product I used to own.
It
> is called the BHI ANEM (Mk. II). Sadly, I sold it after getting the K3. I
> should have hung on to it as it has become my benchmark for NR
performance.
>
> These are some sample recordings of the ANEM being turned on and off.
These
> recordings are found on W4RT's website
>
> 20 m SSB <http://www.w4rt.com/BHI/20Mband-ssb.wav>
> 80 m SSB <http://www.w4rt.com/BHI/80conv-ssb.wav>
> 80 m SSB <http://www.w4rt.com/BHI/80Mconv2-ssb.wav>
>
> I've also compared the K3's NR performance to that of the Icom 756 Pro 3
> which has similar NR reduction properties - albeit not as effective - as
the
> ANEM.
>
> Perhaps I am being subjective or overly critical, but one thing you can
> easily notice with the ANEM recordings is that speech volume doesn't get
as
> affected as the K3s. This is really surprising to me as the NR for the
ANEM
> is AF rather than IF like what's used in our radios. This leads me to
> believe that the ANEM's NR algorithms are more effective in reducing
> background noise while leaving speech unaffected.
>
> What do you guys think?
>
> Sorry for the long email. Many thanks in advance for your
ideas/suggestions.
> --
> 73 de James K2QI
> President UNARC/4U1UN

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K2QI

Re: K3: noise reduction performance

In reply to this post by K2QI

Hello Group,

I went ahead and ordered another BHI ANEM module, but I still have high
hopes that the K3's NR performance will improve. I believe one of the
biggest issues is related to audio fidelity when the NR is activated. I
find myself having to turn up the AF gain in order to compensate for the
drop in speech volume when NR is on. Doing so however increases the volume
of band noise which sort of mitigates any benefits the NR brought with it.
Think of it sort of as a see-saw where one is always adjusting one variable
to compensate for another.

I hope Lyle will read this and perhaps be able to comment directly.

Mni tnx es vy 73,
James K2QI

On Sat, Nov 27, 2010 at 7:16 AM, James Sarte (K2QI) <[hidden email]>wrote:

> Hello Elecrafters,
>
> Regarding the issue of NR, I know this can be a touchy subject and most
> will say its very subjective. This post isn't intended as a complaint or
> criticism. Instead, I hope through constructive discussions, more
> improvements to the K3's NR performance will be realized. I'd like to begin
> by saying that Lyle and crew have a done a fantastic job to date with the
> K3's NR. I've had the privilege of watching the K3's NR function improve
> over time. The boys at Aptos should really be commended for listening to
> their customers.
>
> With that said, the recent CQSS has made me realize that there is still
> room for improvement. During the SS, I used NR extensively in combination
> with RF gain and filter hi-cut/lo-cut/shift settings. NR when used in
> combination with the aforementioned K3 adjustments can and does work well.
> The problem that I believe remains however is the algorithm used still
> seems too broad in its rejection calculations; what I mean is that SSB
> settings (i.e. F5-1 and higher) don't seem to be selective enough to reduce
> noise while allowing speech patterns to remain unaffected. In other words,
> the DSP sounds like its reducing everything within its passband. To my
> ears, the NR doesn't seem to make speech "pop out" quite as effectively has
> other NR implementations. This can be seen by a not-so-subtle reduction in
> speech volume whenever the NR is turned on. The NR behavior is consistent
> regardless of AGC slope or threshold settings.
>
> Below are several links to audio recordings of a product I used to own. It
> is called the BHI ANEM (Mk. II). Sadly, I sold it after getting the K3. I
> should have hung on to it as it has become my benchmark for NR performance.
>
> These are some sample recordings of the ANEM being turned on and off.
> These recordings are found on W4RT's website
>
> 20 m SSB <http://www.w4rt.com/BHI/20Mband-ssb.wav>
> 80 m SSB <http://www.w4rt.com/BHI/80conv-ssb.wav>
> 80 m SSB <http://www.w4rt.com/BHI/80Mconv2-ssb.wav>
>
> I've also compared the K3's NR performance to that of the Icom 756 Pro 3
> which has similar NR reduction properties - albeit not as effective - as the
> ANEM.
>
> Perhaps I am being subjective or overly critical, but one thing you can
> easily notice with the ANEM recordings is that speech volume doesn't get as
> affected as the K3s. This is really surprising to me as the NR for the ANEM
> is AF rather than IF like what's used in our radios. This leads me to
> believe that the ANEM's NR algorithms are more effective in reducing
> background noise while leaving speech unaffected.
>
> What do you guys think?
>
> Sorry for the long email. Many thanks in advance for your
> ideas/suggestions.
> <http://www.w4rt.com/BHI/20Mband-ssb.wav>
> --
> 73 de James K2QI
> President UNARC/4U1UN
>
>

--... ...-- -.. . .--- .- -- . ...

KK7P

Re: K3: noise reduction performance

Psycho-acoustics is fun! Some people swear by the K3 NR, others swear
at it :-)

Making further changes to the K3 NR remains a possibility, but is not a
particularly high priority at the moment. Priorities can and do change...

73,

Lyle KK7P

> I hope Lyle will read this and perhaps be able to comment directly.

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David Pratt

K3: firmware priorities

How high is the priority for improving the K144XV S-meter, Lyle?

Also, the K144XV frequency drift? Almost everyone I work on 2 meters
tell me about my drifting signal :-(

73 de David G4DMP

In a recent message, Lyle Johnson <[hidden email]> writes
>
>Making further changes to the K3 NR remains a possibility, but is not a
>particularly high priority at the moment. Priorities can and do change...
>
>73,
>
>Lyle KK7P

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K2QI

Re: K3: noise reduction performance

In reply to this post by KK7P

Hi Lyle!

Indeed, this is a very subjective issue. One issue though that many will
probably agree with me on is the decrease in audio fidelity whenever NR is
engaged; i.e. volume of speech drops in relation to NR. Would it be
possible to alter the algorithm to prevent this from happening?

It seems to me like the current NR algorithm reduces *everything* within the
passband, including spoken word.

73,
James K2QI

On Tue, Nov 30, 2010 at 10:43 AM, Lyle Johnson <[hidden email]> wrote:

> Psycho-acoustics is fun! Some people swear by the K3 NR, others swear
> at it :-)
>
> Making further changes to the K3 NR remains a possibility, but is not a
> particularly high priority at the moment. Priorities can and do change...
>
> 73,
>
> Lyle KK7P
>
> > I hope Lyle will read this and perhaps be able to comment directly.
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

--
73 de James K2QI
President UNARC/4U1UN
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--... ...-- -.. . .--- .- -- . ...

Gary Gregory

Re: K3: noise reduction performance

James,

I concur. There is a noticeable drop in 'audio level' when I activate NR and
it does not depend on the settings from what I can tell.

I would hope this does creep up the list quite a bit as I feel it has been
left as a dormant issue long enough.

Gary

On Wed, Dec 1, 2010 at 2:13 AM, James Sarte (K2QI) <[hidden email]>wrote:

> Hi Lyle!
>
> Indeed, this is a very subjective issue. One issue though that many will
> probably agree with me on is the decrease in audio fidelity whenever NR is
> engaged; i.e. volume of speech drops in relation to NR. Would it be
> possible to alter the algorithm to prevent this from happening?
>
> It seems to me like the current NR algorithm reduces *everything* within
> the
> passband, including spoken word.
>
> 73,
> James K2QI
>
> On Tue, Nov 30, 2010 at 10:43 AM, Lyle Johnson <[hidden email]> wrote:
>
> > Psycho-acoustics is fun! Some people swear by the K3 NR, others swear
> > at it :-)
> >
> > Making further changes to the K3 NR remains a possibility, but is not a
> > particularly high priority at the moment. Priorities can and do
> change...
> >
> > 73,
> >
> > Lyle KK7P
> >
> > > I hope Lyle will read this and perhaps be able to comment directly.
> >
> > ______________________________________________________________
> > Elecraft mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/elecraft
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:[hidden email]
> >
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
> >
>
>
>
> --
> 73 de James K2QI
> President UNARC/4U1UN
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>
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> Please help support this email list: http://www.qsl.net/donate.html
>

--
Gary
VK4FD - Motorhome Mobile
http://www.qsl.net/vk4fd/
K3 #679, P3 #546
For everything else there's Mastercard!!!
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