K3 Noise Reduction

[Lee Trout]

I agree with Roy Morris.  No amount of tinkering with the parameters significantly improves the NR on the K3.  

The Kenwood 480 has dual NR's, one for CW and one for SSB.  Both are much more effective than the K3's NR without causing any degradation to the signal that I can detect.  Thus I use the 480 rather than the K3 under noisy conditions and/or QRN.

I wonder at times if the concept is wrong; perhaps it would be better to forget about "signal enhancement" and concentrate on the noise reduction.

73, Lee (K9CM)

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[David Gilbert]

Is most of this discussion on NR in the K3 from users who would like to
improve the SNR on louder signals for easier listening in noisy
conditions?  

I get the impression we have people expecting different things from
these controls.  The optimum AGC and NR design strategy to improve SNR
for weak signals might be quite a different story than for stronger
signals and noise, even if the SNR's are initially the same.  That might
show up fairly dramatically on a rig with as large a dynamic range as
the K3.

Since I mostly worry about readability on really weak signals I've had a
bit of a hard time understanding what this was all about.  I just use
settings similar to those suggested by W3FPR and K6LL and I've been very
happy with the results ... which are much better than any Icom or
Kenwood I ever owned.

73,
Dave   AB7E



Lee Trout wrote:

> I agree with Roy Morris.  No amount of tinkering with the parameters significantly improves the NR on the K3.  
>
> The Kenwood 480 has dual NR's, one for CW and one for SSB.  Both are much more effective than the K3's NR without causing any degradation to the signal that I can detect.  Thus I use the 480 rather than the K3 under noisy conditions and/or QRN.
>
> I wonder at times if the concept is wrong; perhaps it would be better to forget about "signal enhancement" and concentrate on the noise reduction.
>
> 73, Lee (K9CM)
>
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>  

... [show rest of quote]

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[Bill Steffey NY9H]

I have two "Hear-it" speakers from England's BHI company hooked thru
my microham controller's headphone output....which is connected to
the 7800 & the K3.

With a low- mid aggressive setting they don't sound anything.... but
quieter. (what a concept)...  leave them in line most all the time.

No gurgling, whooshing... or D-Star audio emulations.
(Much better than the NCT licensed stuff Clearspeech/Heil now West
Mountain Radio).

Granted if I was using a GrandioseSweetness18" 3 way, I might have a
different outcome. Then again I could pipe it thru my UREI
"time-aligned" monitors.

40 years in the audio business.....tells me the BHI algorithm is a
winner.... whatever they are doing ...I wish Lyle would do   ( if the
DSP can handle it  ....)
And I do know the existing design does it the other way .....

Seems we revisit this one about every 118 days......

bill

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[WILLIS COOKE]

David, I am a mostly CW operator with only an occasional SSB contact or contests.  I find that I can copy signals on my K3 that I cannot copy on my TS-850, but only a few very weak ones.  The most effective control against noise that I have found is the Width control and in 160 and 80 meter very noisy contacts I find myself at 50 or 100 Hz width.  I find that the signals all sound noisy unless they are very strong, above S9 which are rare in today's propagation.  I can make the signal sound a bit less noisy with the NR, but at the expense of copy ability, especially with code speeds above 20 wpm.  I have never found the NR to be useful for a CW contact.  SSB contacts, even with a setting of F1-1 are distorted enough to be difficult to copy.  For noisy SSB contacts turning off the AGC and reducing the RF Gain seems to be the effective tactic.  

I have been reading what people have to say on this forum and I get further confused about how to properly set up the AGC, NB and NR to make them work to my advantage. I find both of my 20 year old Kenwoods more pleasant to use (a TS-440 and TS-850) but I can work signals with the K3 that I can't work with the others.  The NB is more effective with either of the Kenwoods.

I still think I am doing something terribly wrong with the K3 and I need more contacts to figure it out.  It seems that only 2,000 or so QSOs is not enough.  I need more experience with Ham Radio, perhaps.  Fifty three years does not seem enough.

Willis 'Cookie' Cooke
K5EWJ


--- On Wed, 4/29/09, David Gilbert <[hidden email]> wrote:

> From: David Gilbert <[hidden email]>
> Subject: Re: [Elecraft] K3 Noise Reduction
> To: [hidden email]
> Date: Wednesday, April 29, 2009, 1:41 PM
> Is most of this discussion on NR in the K3 from users who
> would like to
> improve the SNR on louder signals for easier listening in
> noisy
> conditions?  
>
> I get the impression we have people expecting different
> things from
> these controls.

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[Joe Planisky]

Hi Dave,

Thanks for trying to understand.  I can't speak for others, but here's  
my issue with NR.  It's not how it works on weak signals, it's how it  
works on strong ones.

Sometimes I have AGC SLP set to a low value (i.e. this makes weak  
signals sound quieter and strong signals sound louder). I usually have  
RF gain set to max and set AF gain to a comfortable level.  I can tune  
around the band and hear weak and strong signals pass by, but I set my  
AF gain so the strongest signals are tolerably loud.  Now, if I turn  
on NR and set it to a relatively aggressive setting and then tune  
around the band, suddenly the strong signals that would have been  
merely loud with NR off are now painfully loud with NR on.  It's  
hearing-damage loud if I have headphones on (well, that's how it seems  
when you suddenly tune across a S9+20 signal.)

So OK, some say, don't tune around with NR on.  But the same effect  
makes it nearly impossible to use aggressive NR with low AGC SLP  
values on signals with deep QSB.  With NR off, a signal that fades in  
and out between, say, S2 and S9+10 is easily copyable.  With NR on, it  
goes from nearly inaudible to wake-the-neighbors loud.

Yes, there are all kinds of ways to get around it. Increase the AGC  
SLP, ride the AF or RF gain, reduce bandwidth.  All very valid work-
arounds and I use them all at times.  But I really can't imagine that  
the extra 15 to 18 dB boost that aggressive NR gives already strong  
signals is normal, beneficial, or intended behavior.  (If it IS  
considered normal or intended, I wish Wayne or Lyle would speak up and  
I'll shut up about it. :-)  My only other experience with NR was on  
the K2, and I loved it there (although I didn't experiment with the  
settings on the K2 as much as I have on the K3.)

73
--
Joe KB8AP


On Apr 29, 2009, at 1:41 PM, David Gilbert wrote:

>
> Is most of this discussion on NR in the K3 from users who would like  
> to
> improve the SNR on louder signals for easier listening in noisy
> conditions?
>
> I get the impression we have people expecting different things from
> these controls.  The optimum AGC and NR design strategy to improve SNR
> for weak signals might be quite a different story than for stronger
> signals and noise, even if the SNR's are initially the same.  That  
> might
> show up fairly dramatically on a rig with as large a dynamic range as
> the K3.

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[Bill K9YEQ]

Agreed! I have tried a bunch of settings and have some that really suit my
personal preference. Here's what I use on the lowest bands:

PRE off
ATT on

AGC DCY Soft
AGC HLD 0.50
AGC PLS nor
AGC SLP 006
AGC THR 003
AGC--F 120
AGC--S 025
 

Very strong signals may give a little distortion, it could be their signal
is overdriven, but I use the RF control.  Noise from lighting static, and
neighbors very lousy electric fence is not bothersome.  

Hopefully through the sharing of different settings, those who might be a
bit challenged by the flexibility will be helped.

I have saved these settings so I don't lose them when I diddle some more.
:-)


73,

Bill
K9YEQ
K2 #35; KX1 #35; K3 #1744; mini mods
ATS-3B

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of David Gilbert

Is most of this discussion on NR in the K3 from users who would like to
improve the SNR on louder signals for easier listening in noisy
conditions?  

I get the impression we have people expecting different things from
these controls.  The optimum AGC and NR design strategy to improve SNR
for weak signals might be quite a different story than for stronger
signals and noise, even if the SNR's are initially the same.  That might
show up fairly dramatically on a rig with as large a dynamic range as
the K3.

Since I mostly worry about readability on really weak signals I've had a
bit of a hard time understanding what this was all about.  I just use
settings similar to those suggested by W3FPR and K6LL and I've been very
happy with the results ... which are much better than any Icom or
Kenwood I ever owned.

73,
Dave   AB7E

Lee Trout wrote:
> I...............No amount of tinkering with the parameters significantly
improves the NR on the K3.  
>
....................
> I wonder at times if the concept is wrong; perhaps it would be better to
forget about "signal enhancement" and concentrate on the noise reduction.
>
> 73, Lee (K9CM)

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[N5GE]

On Wed, 29 Apr 2009 15:59:35 -0400, "Lee Trout" <[hidden email]>
wrote:

[snip

>I wonder at times if the concept is wrong; perhaps it would be better to forget about "signal enhancement" and concentrate on the noise reduction.

[snip]

Absolutely not!

Let's let Elecraft work out the noise reduction anomalies.  They're
reading you posts and they will react to them.  Be patient.

Tom, N5GE
K3 #806, K3 #1055
XV144, XV432
W1 and other small kits.
http://www.n5ge.com

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[G4POP]

Hi Joe
Your take on the NR discussion is the most accurate so far and confirms exactly my perception of it.

Like Cookie K5EWJ I also find the NR on some of my other rigs very usable whereas the K3 NR is definitely not.

Maybe I, like Cookie, don't have enough experience having only been in the hobby since 1949! but I would prefer NR to be noise reduction not audio amplification and distortion without the need to constantly jiggle the AGC settings to save my eardrums.

Before all of the other K3 devotees jump on me let me say that I love my K3 and would not part with it but it seems to me that this NR issue is being totally ignored.

Terry G4POP

Joe Planisky wrote

Hi Dave,

Thanks for trying to understand.  I can't speak for others, but here's  
my issue with NR.  It's not how it works on weak signals, it's how it  
works on strong ones.

Sometimes I have AGC SLP set to a low value (i.e. this makes weak  
signals sound quieter and strong signals sound louder). I usually have  
RF gain set to max and set AF gain to a comfortable level.  I can tune  
around the band and hear weak and strong signals pass by, but I set my  
AF gain so the strongest signals are tolerably loud.  Now, if I turn  
on NR and set it to a relatively aggressive setting and then tune  
around the band, suddenly the strong signals that would have been  
merely loud with NR off are now painfully loud with NR on.  It's  
hearing-damage loud if I have headphones on (well, that's how it seems  
when you suddenly tune across a S9+20 signal.)

So OK, some say, don't tune around with NR on.  But the same effect  
makes it nearly impossible to use aggressive NR with low AGC SLP  
values on signals with deep QSB.  With NR off, a signal that fades in  
and out between, say, S2 and S9+10 is easily copyable.  With NR on, it  
goes from nearly inaudible to wake-the-neighbors loud.

Yes, there are all kinds of ways to get around it. Increase the AGC  
SLP, ride the AF or RF gain, reduce bandwidth.  All very valid work-
arounds and I use them all at times.  But I really can't imagine that  
the extra 15 to 18 dB boost that aggressive NR gives already strong  
signals is normal, beneficial, or intended behavior.  (If it IS  
considered normal or intended, I wish Wayne or Lyle would speak up and  
I'll shut up about it. :-)  My only other experience with NR was on  
the K2, and I loved it there (although I didn't experiment with the  
settings on the K2 as much as I have on the K3.)

73
--
Joe KB8AP

... [show rest of quote]

... [show rest of quote]

[Stewart Baker]

I agree, whatever algorithm BHI uses,  it really works.

73
Stewart G3RXQ
On Wed, 29 Apr 2009 16:05:07 -0500, Bill NY9H wrote:
> I have two "Hear-it" speakers from England's BHI company hooked
thru
> my microham controller's headphone output....which is connected
to
> the 7800 & the K3.
>
> With a low- mid aggressive setting they don't sound anything....
but
> quieter. (what a concept)...  leave them in line most all the
time.
>
> No gurgling, whooshing... or D-Star audio emulations.
> (Much better than the NCT licensed stuff Clearspeech/Heil now
West
> Mountain Radio).
>
> Granted if I was using a GrandioseSweetness18" 3 way, I might
have a
> different outcome. Then again I could pipe it thru my UREI
> "time-aligned" monitors.
>
> 40 years in the audio business.....tells me the BHI algorithm is
a
> winner.... whatever they are doing ...I wish Lyle would do   (
if the

> DSP can handle it  ....)
> And I do know the existing design does it the other way .....
>
> Seems we revisit this one about every 118 days......
>
> bill
>
> ______________________________________________________________
> 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:

... [show rest of quote]

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[Brett Howard]

I have to agree fully that in the CW land I find that I rarely ever go
into look at NR.  When I first got the radio I was in there trying it
all the time cause I came from Kenwoods.  But soon after playing with
all the settings across many differing condx I found that its just best
to leave it be and use the width knob cause the NR don't do diddly for
me 95% of the time.

If its an already strong signal and its at slow speeds then NR can tend
do help but it doesn't do much more than simply turning the width down
does.  Perhaps I'm just perceiving it differently in that my Kenwood had
a 500Hz narrowest filter...  When there if there is a good strong signal
thats going slower then sure we're ok and it helps but when you're at
narrower widths there it doesn't do much.... But honestly I don't know
if it really can do much once you're down that narrow there is a lot
less data to play with.

~Brett KC7OTG

On Wed, 2009-04-29 at 14:14 -0700, WILLIS COOKE wrote:

> David, I am a mostly CW operator with only an occasional SSB contact or contests.  I find that I can copy signals on my K3 that I cannot copy on my TS-850, but only a few very weak ones.  The most effective control against noise that I have found is the Width control and in 160 and 80 meter very noisy contacts I find myself at 50 or 100 Hz width.  I find that the signals all sound noisy unless they are very strong, above S9 which are rare in today's propagation.  I can make the signal sound a bit less noisy with the NR, but at the expense of copy ability, especially with code speeds above 20 wpm.  I have never found the NR to be useful for a CW contact.  SSB contacts, even with a setting of F1-1 are distorted enough to be difficult to copy.  For noisy SSB contacts turning off the AGC and reducing the RF Gain seems to be the effective tactic.  
>
> I have been reading what people have to say on this forum and I get further confused about how to properly set up the AGC, NB and NR to make them work to my advantage. I find both of my 20 year old Kenwoods more pleasant to use (a TS-440 and TS-850) but I can work signals with the K3 that I can't work with the others.  The NB is more effective with either of the Kenwoods.
>
> I still think I am doing something terribly wrong with the K3 and I need more contacts to figure it out.  It seems that only 2,000 or so QSOs is not enough.  I need more experience with Ham Radio, perhaps.  Fifty three years does not seem enough.
>
> Willis 'Cookie' Cooke
> K5EWJ
>
>
> --- On Wed, 4/29/09, David Gilbert <[hidden email]> wrote:
>
> > From: David Gilbert <[hidden email]>
> > Subject: Re: [Elecraft] K3 Noise Reduction
> > To: [hidden email]
> > Date: Wednesday, April 29, 2009, 1:41 PM
> > Is most of this discussion on NR in the K3 from users who
> > would like to
> > improve the SNR on louder signals for easier listening in
> > noisy
> > conditions?  
> >
> > I get the impression we have people expecting different
> > things from
> > these controls.
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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> Post: mailto:[hidden email]
>
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... [show rest of quote]

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[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

   
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[Don Wilhelm-4]

Trevor,

Those Noise Reduction algorithms you refer to seem to be quite clever
and effective.  They appear to be close to the NR that I have in my
hearing aids which does a great job of extracting speech from noise.
Unfortunately, the NR in my hearing aids also thinks sustained musical
notes are noise, and by the same token, CW can also be considered noise.
Nothing is perfect, and compromises must be made, but the current NR
algorithm used in the K3 does not work for me either - it causes severe
distortion of SSB signals (speech) and while my AGC settings do not
create the wild signal increases on CW that others have reported, I
usually find that narrow filtering is more pleasant to use than the NR
function.
Perhaps Lyle is looking at other alternatives for NR in the K3, but I do
know that he is quite busy with other 'irons in the fire' right now, so
patience is a virtue for now and we could possibly discover improvements
down the road.
All these thoughts are entirely my own and are based on pure speculation
- I have no further information than what has been posted to the
Elecraft reflector.

73,
Don W3FPR

Trevor Smithers wrote:

> 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
>
>    
> ______________________________________________________________
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>
>
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[Steven.Zabarnick]

Hmm, are Lyle's "other irons in the fire" being heated for Eric's "other
fish to fry"?  :-)

More seriously, I also would love to see changes to the noise reduction,
particularly to help
with weak signal work. I'm not sure why anyone cares about noise reduction
for
strong signals -- I just turn down the AF gain and the noise goes away :-)

Steve N9SZ


Don W3FPR wrote:
Perhaps Lyle is looking at other alternatives for NR in the K3, but I do
know that he is quite busy with other 'irons in the fire' right now, so
patience is a virtue for now and we could possibly discover improvements
down the road.

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[K2QI]

Regarding noise reduction and the BHI products; I've noticed that the BHI
ANEM works substantially better than the K3's NR.  For whatever reason,
whenever I switch NR on, the band noise seems to get attenuated slightly,
but then reshaped to resemble noise in a tunnel.  It's very tiring to listen
too.  

Any suggestions?

73 de James K3JPS

Trevor Smithers wrote:
> 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

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[Eric Swartz - WA6HHQ]

Lyle is looking at the NR code. Let's rest this thread for now.

We'll pop up here when we have something new to try. :-)

73, Eric   WA6HHQ

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[k6dgw]

Don Wilhelm wrote:
>
> Those Noise Reduction algorithms you refer to seem to be quite clever
> and effective.  They appear to be close to the NR that I have in my
> hearing aids which does a great job of extracting speech from noise.
> Unfortunately, the NR in my hearing aids also thinks sustained musical
> notes are noise, and by the same token, CW can also be considered noise.

My experience also.  The VA gave me some new digital [DSP] hearing aids a
few years ago.  They will notch a fire truck siren down to a tolerable
level, and do a fine job of extracting voice and music from noise [except
for sustained notes].  I hadn't heard birds in nearly 40 years until I got
these.  However, they apparently think CW is a fire truck.

I am finding that my K3 NR performance is very sensitive to other RX
settings as well as the DSP BW.  The recently posted suggestions for AGC
settings have helped a lot.  I'm pretty much CW-only because of my
hearing, I have the stock roofing filters, and I usually run the DSP
around 250 Hz.  Engaging NR at one of the lesser aggressive settings
raises the volume of the signal, I turn down the AF Gain, and the noise
subsides nicely with the signal now standing out in my headphones better.
There seems to be a threshold level below which a very weak signal can't
be found by the NR algorithm but I haven't had time to experiment with the
NR settings yet.  Possibly a more agressive setting will lower that
threshold.  Really agressive settings seem to create more garbage than
they reduce noise.  Haven't gotten to SSB yet.

My K3 is definitely NOT your father's radio :-)

73,

Fred K6DGW
- Northern California Contest Club
- Auburn CA [Placer County, CM98LW]


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[Dave Van Wallaghen]

[hidden email] wrote:
>  They will notch a fire truck siren down to a tolerable
> level

I don't know if I like that or not ;-)

> However, they apparently think CW is a fire truck.
>
I can safely say that for the many years I have on the job, CW is
definitely not a fire truck :-) Drivers would probably get out of the
way for CW ;-)

73,
Dave W8FGU

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