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K3/K3S noise blanker performance greatly enhanced (at my QTH) -- need testers

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Tim Tucker

Re: K3/K3S noise blanker performance greatly enhanced (at my QTH) -- need testers

What, exactly, does the discussion of the Collins NB filter have to do with
the experimental NB thing Wayne is working on? Can we stick to the topic
at hand?

On Thu, Feb 4, 2016 at 3:46 PM, Bob McGraw K4TAX <[hidden email]>
wrote:

> The purpose of a Noise Blanker is to act only on repetitive pulse type
> noise. They do little to nothing for random type noise issues.
>
> 73
> Bob, K4TAX
>
> On 2/4/2016 5:29 PM, W5RDW wrote:
>
>> I think the Collins NB was most effective on pulse type (ignition) noise
>> encountered in mobile applications.
>>
>> http://collinsradio.org/archives/manuals/136B-2_5th-ed-11-66_.pdf
>>
>>
>>
>>
>>
>
> ______________________________________________________________
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> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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> Post: mailto:[hidden email]
>
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> Message delivered to [hidden email]
>

--
Owner, worldwidedx.com
AE6LX, Amateur Radio
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Wes (N7WS)

Re: K3/K3S noise blanker performance greatly enhanced (at my QTH) -- need testers

In reply to this post by W5RDW

I owned a 75A-4 once, but I never thought to use it mobile:-)

On 2/4/2016 4:29 PM, W5RDW wrote:
> I think the Collins NB was most effective on pulse type (ignition) noise
> encountered in mobile applications.
>
> http://collinsradio.org/archives/manuals/136B-2_5th-ed-11-66_.pdf
>
>

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Bob McGraw - K4TAX

Re: K3/K3S noise blanker performance greatly enhanced (at my QTH) -- need testers

In reply to this post by Tim Tucker

In an earlier post it was asked:

"> I would also like to see a technical description beyond the

> hand-waving in the manual of how noise blanking is performed. For
> example, I fail to see any dedicated delay in the signal path to
> create timing coincidence between the noise pulse and the blanking
> gate. Perhaps it's inherent in the design, but I would like to see
> some words that say so.
>
> If it's going to be necessary for me to set a blanking threshold
> (something I think could be automatic) then why can't the radio
> generate a blanking pulse that persists as long as that threshold is
> exceeded. Why do I also have to adjust that? If the pulse is so long
> that intelligibility suffers then that noise isn't amenable to being
> blanked and blanking needs to be disabled."

Thus the various discussions and references have appeared.

73
Bob, K4TAX

On 2/4/2016 6:21 PM, Tim Tucker wrote:

> What, exactly, does the discussion of the Collins NB filter have to do with
> the experimental NB thing Wayne is working on? Can we stick to the topic
> at hand?
>
> On Thu, Feb 4, 2016 at 3:46 PM, Bob McGraw K4TAX <[hidden email]>
> wrote:
>
>> The purpose of a Noise Blanker is to act only on repetitive pulse type
>> noise. They do little to nothing for random type noise issues.
>>
>> 73
>> Bob, K4TAX
>>
>> On 2/4/2016 5:29 PM, W5RDW wrote:
>>
>>> I think the Collins NB was most effective on pulse type (ignition) noise
>>> encountered in mobile applications.
>>>
>>> http://collinsradio.org/archives/manuals/136B-2_5th-ed-11-66_.pdf
>>>
>>>
>>>
>>>
>>>
>> ______________________________________________________________
>> 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
>> Message delivered to [hidden email]
>>
>
>

Wes (N7WS)

Re: K3/K3S noise blanker performance greatly enhanced (at my QTH) -- need testers

In reply to this post by Tim Tucker

It's called topic drift. Without GPS stabilization it happens.

On 2/4/2016 5:21 PM, Tim Tucker wrote:
> What, exactly, does the discussion of the Collins NB filter have to do with
> the experimental NB thing Wayne is working on? Can we stick to the topic
> at hand?
>

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Wes (N7WS)

Re: K3/K3S noise blanker performance greatly enhanced (at my QTH) -- need testers

In reply to this post by Bob McGraw - K4TAX

Not to put too fine of a point on it but strictly speaking, that is incorrect.
The characteristics of a pulse that can be blanked are:

1) its amplitude is sufficiently greater than the desired signal so it can be
detected as undesired (noise)

2) its duration isn't so long that the "hole" punched in the signal appreciably
degrades intelligibility.

Note that *one* pulse is all that is needed. A repetitive pulse train that
satisfies 1) might not satisfy 2, if the pulses are too close together.
Conversely, totally random pulses can satisfy both 1 and 2.

Now in common ham lingo, what you say is true: "repetitive noise" is something
like ignition noise and "random noise" is static crashes or the like, so those
terms meet my previously stated criteria.

On 2/4/2016 4:46 PM, Bob McGraw K4TAX wrote:

> The purpose of a Noise Blanker is to act only on repetitive pulse type noise.
> They do little to nothing for random type noise issues.
>
> 73
> Bob, K4TAX
>
> On 2/4/2016 5:29 PM, W5RDW wrote:
>> I think the Collins NB was most effective on pulse type (ignition) noise
>> encountered in mobile applications.
>>
>> http://collinsradio.org/archives/manuals/136B-2_5th-ed-11-66_.pdf
>>
>>
>>
>>
>
>
> ______________________________________________________________
> 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
> Message delivered to [hidden email]
>

RobertG

Re: K3/K3S noise blanker performance greatly enhanced (at my QTH) -- need testers

In reply to this post by wayne burdick

My widest filter is 2.8MHz [the optional, 8-pole ssb filter]. Is the
technique that Wayne is describing not applicable in my situation?
...robert

On 02/04/2016 3:03 AM, Wayne Burdick wrote:

> Hi all,
>
> If you have...
>
> - really ugly noise sources that neither of the K3/K3S noise blankers completely clean up, and
>
> - a 6-kHz crystal filter, and
>
> - a narrow crystal filter (200-1000 Hz)
>
> ...then you may want to try an experimental technique I've been using the past couple of days. In many cases it produces dramatically improved blanking, at least in narrow-band modes (CW, PSK, FSK). I've been able to hear many weak signals that I simply couldn't hear before.
>
> It may also work for SSB signals in conjunction with a 15-kHz crystal filter, but I haven't tried that yet.
>
> The kind of noise I'm talking about is often quite unstable, with a buzzy sound, possibly drifting around a bit in frequency and amplitude. Light dimmers, switching power supplies, and various other devices create such noise. The noise may be narrowband: as you tune the VFO, you may find there's a "hump" of noise that's anywhere from 2 kHz to 50 kHz wide. It may also have very complex waveform with multiple noise pulses back-to-back in a burst.
>
> These types of noise are difficult to deal with. The IF blanker's signal path may be too wide (0.2 to 2 MHz), resulting in too little energy in-band to trigger the gating signal. The DSP blanker's RF signal path may be too narrow, making it hard for the DSP to distinguish noise from desired signal.
>
> * * *
>
> Setup:
>
> 1. Connect the radio to a computer running K3 Utility. Go into the Configuration / Configure Crystal Filter setup screen.
>
> 2. Find your 6-kHz filter (probably FL1 or FL2). Now the fun part: fake out the firmware by entering a bandwidth for this filter that's just 50 Hz wider than your narrow CW filter (ideally 250-500 Hz). *Do not* change the filter offset. But *do* make sure that the 6-kHz filter's CW and DATA enable boxes are checked.
>
> 3. Click "OK" to save this experimental crystal filter configuration setup.
>
> 4. You will now find that when the WIDTH control is rotated from, say, 0.40 to 0.45, the XFIL selection will jump from something like FL4 directly to FL1 or FL2 (your 6-kHz filter). That, hopefully, is the boundary where magic may occur, below.
>
> * * *
>
> The Experiment:
>
> 1. Find one of your most offensive local noise sources. I have them on most low bands. The stronger the amplitude the better. Narrowband sources may provide the most dramatic results.
>
> 2. Back down the AF gain control, then *turn off AGC*. You may need to use the RF gain to keep the signal from clipping.
>
> NOTE: The reason for doing this test without AGC is to make sure you can hear the full effect of applied noise reduction. AGC flattens out the receiver's audio response, making it hard to compare different settings. (If you find that the noise-remediation trick works, you can later turn AGC back on, and while the effect won't be as obvious, any benefit in signal-to-noise ratio will still apply.)
>
> 3. Select CW mode and adjust the WIDTH control for your narrow filter's bandwidth (example: "BW 0.40").
>
> 4. Turn on the noise blanker (tap NB) and hold NB (LEVEL) to access the blanker parameters.
>
> 5. Set the IF blanker to OFF (VFO B). Then experiment with the DSP blanker settings (VFO A) to obtain the best possible reduction in signal.
>
> 6. While still the LEVEL parameters are still displayed, adjust the WIDTH control to the next step up (example: "BW 0.45"). This should kick in the 6-kHz filter, *but the DSP bandwidth and filter graphic will still show a narrow passband*. In other words, you're widening out the crystal filter but making very little change in the DSP's internal filter bandwidth (15 kHz IF, and AF).
>
> 7. Now re-optimize the DSP noise blanker settings for the 6-kHz filter case. Did the noise drop? (If you have a signal generator, e.g. an Elecraft XG3, you might put an antenna on it and generate a weak signal right in the middle of the noise to get more definitive results.)
>
> 8. Try it on other noise sources. It may help on some but not others, due to the wide variance in noise signals.
>
> Please log your results and report them to the list, at least until Eric shuts down the thread :)
>
> * * *
>
> IMPORTANT:
>
> As you can imagine, opening up the crystal filter bandwidth much wider than the DSP bandwidth will make the receiver more susceptible to in-band interference. If necessary, use RF GAIN, preeamp, and attenuator settings to reduce all interfering signals to a manageable level.
>
> I find there are many occasions on which better blanking is really critical, even if gain must be reduced in order to take advantage of it.
>
> * * *
>
> If we get enough positive responses from this experiment, we'll provide a simply, intuitive way of selecting the 6-kHz filter for noise blanking purposes. And maybe the 15 kHz filter for SSB use, if applicable. For example, we might add more selections to the DSP blanker parameter (presently t1-1 to 3-7). Suggestions welcome.
>
> 73,
> Wayne
> N6KR
>
>
>
>
>
>
>
> ______________________________________________________________
> 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
> Message delivered to [hidden email]
>

--
Robert G Strickland, PhD ABPH - KE2WY
[hidden email]
Syracuse, New York, USA
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NK7Z

Re: K3/K3S noise blanker performance greatly enhanced (at my QTH) -- need testers

In reply to this post by wayne burdick

Hi Wayne,

On list report as you asked for...

Set up as described, only using a 13KHz filter in F1 position...

Using a florescent light, which makes a rather ugly wide band noise,
only on 18 MHz., I performed a sort of blind test....

After doing the full setup as you described on a very weak CW station,
I hit the NB button as fast as I could for several seconds while
looking away from the radio... This confused me as to if it was on or
off...

I then while still looking away from the radio brought the NB on and
off line, and stopped on teh CW that was easiest to copy.

I did this five times, and after each test, I re-scrambled my memory by
again, hitting the NB switch many times, and looking away from the
radio.

Five out of five times the NB was off when I stopped, indicating that
the NB made the CW harder to copy.

Sorry... I will try later tonight, when all the Horticultural lights
come on line on 40 meters, which has tons of RFI from them. I will
report again...

--
73's, and thanks,
Dave

For software/hardware reviews see:
http://www.nk7z.net

For MixW support see:
https://groups.yahoo.com/neo/groups/mixw/info

For SSTV help see:
http://groups.yahoo.com/neo/groups/MM-SSTV/info

On Wed, 2016-02-03 at 19:03 -0800, Wayne Burdick wrote:

> Hi all,
>
> If you have...
>
> - really ugly noise sources that neither of the K3/K3S noise blankers
> completely clean up, and
>
> - a 6-kHz crystal filter, and
>
> - a narrow crystal filter (200-1000 Hz)
>
> ...then you may want to try an experimental technique I've been using
> the past couple of days. In many cases it produces dramatically
> improved blanking, at least in narrow-band modes (CW, PSK, FSK). I've
> been able to hear many weak signals that I simply couldn't hear
> before.
>
> It may also work for SSB signals in conjunction with a 15-kHz crystal
> filter, but I haven't tried that yet.
>
> The kind of noise I'm talking about is often quite unstable, with a
> buzzy sound, possibly drifting around a bit in frequency and
> amplitude. Light dimmers, switching power supplies, and various other
> devices create such noise. The noise may be narrowband: as you tune
> the VFO, you may find there's a "hump" of noise that's anywhere from
> 2 kHz to 50 kHz wide. It may also have very complex waveform with
> multiple noise pulses back-to-back in a burst.
>
> These types of noise are difficult to deal with. The IF blanker's
> signal path may be too wide (0.2 to 2 MHz), resulting in too little
> energy in-band to trigger the gating signal. The DSP blanker's RF
> signal path may be too narrow, making it hard for the DSP to
> distinguish noise from desired signal.
>
> * * *
>
> Setup:
>
> 1. Connect the radio to a computer running K3 Utility. Go into the
> Configuration / Configure Crystal Filter setup screen.
>
> 2. Find your 6-kHz filter (probably FL1 or FL2). Now the fun part:
> fake out the firmware by entering a bandwidth for this filter that's
> just 50 Hz wider than your narrow CW filter (ideally 250-500 Hz). *Do
> not* change the filter offset. But *do* make sure that the 6-kHz
> filter's CW and DATA enable boxes are checked.
>
> 3. Click "OK" to save this experimental crystal filter configuration
> setup.
>
> 4. You will now find that when the WIDTH control is rotated from,
> say, 0.40 to 0.45, the XFIL selection will jump from something like
> FL4 directly to FL1 or FL2 (your 6-kHz filter). That, hopefully, is
> the boundary where magic may occur, below.
>
> * * *
>
> The Experiment:
>
> 1. Find one of your most offensive local noise sources. I have them
> on most low bands. The stronger the amplitude the better. Narrowband
> sources may provide the most dramatic results.
>
> 2. Back down the AF gain control, then *turn off AGC*. You may need
> to use the RF gain to keep the signal from clipping.
>
> NOTE: The reason for doing this test without AGC is to make sure you
> can hear the full effect of applied noise reduction. AGC flattens out
> the receiver's audio response, making it hard to compare different
> settings. (If you find that the noise-remediation trick works, you
> can later turn AGC back on, and while the effect won't be as obvious,
> any benefit in signal-to-noise ratio will still apply.)
>
> 3. Select CW mode and adjust the WIDTH control for your narrow
> filter's bandwidth (example: "BW 0.40").
>
> 4. Turn on the noise blanker (tap NB) and hold NB (LEVEL) to access
> the blanker parameters.
>
> 5. Set the IF blanker to OFF (VFO B). Then experiment with the DSP
> blanker settings (VFO A) to obtain the best possible reduction in
> signal.
>
> 6. While still the LEVEL parameters are still displayed, adjust the
> WIDTH control to the next step up (example: "BW 0.45"). This should
> kick in the 6-kHz filter, *but the DSP bandwidth and filter graphic
> will still show a narrow passband*. In other words, you're widening
> out the crystal filter but making very little change in the DSP's
> internal filter bandwidth (15 kHz IF, and AF).
>
> 7. Now re-optimize the DSP noise blanker settings for the 6-kHz
> filter case. Did the noise drop? (If you have a signal generator,
> e.g. an Elecraft XG3, you might put an antenna on it and generate a
> weak signal right in the middle of the noise to get more definitive
> results.)
>
> 8. Try it on other noise sources. It may help on some but not others,
> due to the wide variance in noise signals.
>
> Please log your results and report them to the list, at least until
> Eric shuts down the thread :)
>
> * * *
>
> IMPORTANT:
>
> As you can imagine, opening up the crystal filter bandwidth much
> wider than the DSP bandwidth will make the receiver more susceptible
> to in-band interference. If necessary, use RF GAIN, preeamp, and
> attenuator settings to reduce all interfering signals to a manageable
> level.
>
> I find there are many occasions on which better blanking is really
> critical, even if gain must be reduced in order to take advantage of
> it.
>
> * * *
>
> If we get enough positive responses from this experiment, we'll
> provide a simply, intuitive way of selecting the 6-kHz filter for
> noise blanking purposes. And maybe the 15 kHz filter for SSB use, if
> applicable. For example, we might add more selections to the DSP
> blanker parameter (presently t1-1 to 3-7). Suggestions welcome.
>
> 73,
> Wayne
> N6KR
>
>
>
>
>
>
>
> ______________________________________________________________
> 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
> Message delivered to [hidden email]

wayne burdick

Re: K3/K3S noise blanker performance greatly enhanced (at my QTH) -- need testers

Administrator

In reply to this post by RobertG

2.8 kHz should give some improvement over a narrow filter on some types of noise. Worth a try. Just temporarily tell the firmware that it's a little bit wider than your narrow filter, then use the WIDTH control to switch between narrow and wide. Re-optimize the NB settings each time.

Wayne
N6KR

On Feb 5, 2016, at 8:57 AM, Robert G Strickland <[hidden email]> wrote:

> My widest filter is 2.8MHz [the optional, 8-pole ssb filter]. Is the technique that Wayne is describing not applicable in my situation?
> …robert

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drewko

Re: K3/K3S noise blanker performance greatly enhanced (at my QTH) -- need testers

In reply to this post by NK7Z

I'm glad that noise solutions are being investigated. I think advances
in NR/NB would be of more importance to many hams than close-in dynamic
range, however useful the improvement in those attention-getting figures
are. On a day to day basis noise is the top culprit for many of us.

73,
Drew
AF2Z

On 02/05/16 12:57, Dave Cole wrote:

> Hi Wayne,
>
> On list report as you asked for...
>
> Set up as described, only using a 13KHz filter in F1 position...
>
> Using a florescent light, which makes a rather ugly wide band noise,
> only on 18 MHz., I performed a sort of blind test....
>
> After doing the full setup as you described on a very weak CW station,
> I hit the NB button as fast as I could for several seconds while
> looking away from the radio... This confused me as to if it was on or
> off...
>
> I then while still looking away from the radio brought the NB on and
> off line, and stopped on teh CW that was easiest to copy.
>
> I did this five times, and after each test, I re-scrambled my memory by
> again, hitting the NB switch many times, and looking away from the
> radio.
>
> Five out of five times the NB was off when I stopped, indicating that
> the NB made the CW harder to copy.
>
> Sorry... I will try later tonight, when all the Horticultural lights
> come on line on 40 meters, which has tons of RFI from them. I will
> report again...
>
>

NK7Z

Re: K3/K3S noise blanker performance greatly enhanced (at my QTH) -- need testers

In reply to this post by NK7Z

Wayne,

Second report using Horticultural lights as noise source.

Each evening 40 lights up with grow lights, and the results with them
are much different than the previous results, the grow lights are cut
back to the point I can hear additional stations, but only if I use
headphones...

Did the test much as before, and it does seem that the CW sigs are a
bit better than in previous tests, but it is a close call for me, and I
am not sure how much of this is imagination... A good chunk of my
noise is not shot type RFI, but broad spectrum hash, with well rounded
peaks, not spikes. This method seems to remove spiky RFI better than
wide RFI... More as I test...

My RFI level is low tonight, every so often I get a real hummer of an
RFI signal... I will test on that...

--
73's, and thanks,
Dave

For software/hardware reviews see:
http://www.nk7z.net

For MixW support see:
https://groups.yahoo.com/neo/groups/mixw/info

For SSTV help see:
http://groups.yahoo.com/neo/groups/MM-SSTV/info

On Fri, 2016-02-05 at 09:57 -0800, Dave Cole wrote:

> Hi Wayne,
>
> On list report as you asked for...
>
> Set up as described, only using a 13KHz filter in F1 position...
>
> Using a florescent light, which makes a rather ugly wide band noise,
> only on 18 MHz., I performed a sort of blind test....
>
> After doing the full setup as you described on a very weak CW
> station,
> I hit the NB button as fast as I could for several seconds while
> looking away from the radio... This confused me as to if it was on
> or
> off...
>
> I then while still looking away from the radio brought the NB on and
> off line, and stopped on teh CW that was easiest to copy.
>
> I did this five times, and after each test, I re-scrambled my memory
> by
> again, hitting the NB switch many times, and looking away from the
> radio.
>
> Five out of five times the NB was off when I stopped, indicating that
> the NB made the CW harder to copy.
>
> Sorry... I will try later tonight, when all the Horticultural lights
> come on line on 40 meters, which has tons of RFI from them. I will
> report again...
>
>

Bill W4ZV

Re: K3/K3S noise blanker performance greatly enhanced (at my QTH) -- need testers

In reply to this post by wayne burdick

wayne burdick wrote

2.8 kHz should give some improvement over a narrow filter on some types of noise. Worth a try. Just temporarily tell the firmware that it's a little bit wider than your narrow filter, then use the WIDTH control to switch between narrow and wide. Re-optimize the NB settings each time.

I've been having a problem with a pulse type electric fencer (not the 60 Hz cycling buzz type which is impossible to cure with a blanker). Most radios' NBs deal effectively with pulses but for some reason (firmware change) my K3 (#4717) is not. I decided to try Wayne's suggestion even though I only have the 2.7 kHz stock filter.

The problem with Wayne's suggestion is that the K3 Utility will not accept 0.45 as a valid width for the 2.7 kHz filter because it is used for TX on CW/SSB and bandwidths <2.7 kHz are not allowed. Is there a workaround for this or am I doing something wrong?

73, Bill W4ZV

Vic Rosenthal

Re: K3/K3S noise blanker performance greatly enhanced (at my QTH) -- need testers

I just discovered the same thing. I found the perfect noise to try it on
on 15m, too.

73,
Vic, 4X6GP/K2VCO
Rehovot, Israel
http://www.qsl.net/k2vco/

On 6 Feb 2016 12:34, Bill W4ZV wrote:

> wayne burdick wrote
>> 2.8 kHz should give some improvement over a narrow filter on some types of
>> noise. Worth a try. Just temporarily tell the firmware that it's a little
>> bit wider than your narrow filter, then use the WIDTH control to switch
>> between narrow and wide. Re-optimize the NB settings each time.
>
> I've been having a problem with a pulse type electric fencer (not the 60 Hz
> cycling buzz type which is impossible to cure with a blanker). Most radios'
> NBs deal effectively with pulses but for some reason (firmware change) my K3
> (#4717) is not. I decided to try Wayne's suggestion even though I only have
> the 2.7 kHz stock filter.
>
> The problem with Wayne's suggestion is that the K3 Utility will not accept
> 0.45 as a valid width for the 2.7 kHz filter because it is used for TX on
> CW/SSB and bandwidths <2.7 kHz are not allowed. Is there a workaround for
> this or am I doing something wrong?
>
> 73, Bill W4ZV

john@kk9a.com

Re: K3/K3S noise blanker performance greatly enhanced (at my QTH) -- need testers

In reply to this post by wayne burdick

Even if this works for your noise, I wonder how well it will work using a
wide roofing filter in contest conditions.

Perhaps for RX testing only you can select a different narrower TX filter?

John KK9A

Bill W4ZV btippett at alum.mit.edu
Sat Feb 6 05:34:34 EST 2016

I've been having a problem with a pulse type electric fencer (not the 60 Hz
cycling buzz type which is impossible to cure with a blanker). Most radios'
NBs deal effectively with pulses but for some reason (firmware change) my K3
(#4717) is not. I decided to try Wayne's suggestion even though I only have
the 2.7 kHz stock filter.

The problem with Wayne's suggestion is that the K3 Utility will not accept
0.45 as a valid width for the 2.7 kHz filter because it is used for TX on
CW/SSB and bandwidths <2.7 kHz are not allowed. Is there a workaround for
this or am I doing something wrong?

73, Bill W4ZV

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Guy Olinger K2AV

Re: K3/K3S noise blanker performance greatly enhanced (at my QTH) -- need testers

In reply to this post by Bill W4ZV

Hi Bill. Does the same thing happen if you use the filters in the SubRX for
the experiment? 73, Guy K2AV

On Saturday, February 6, 2016, Bill W4ZV <[hidden email]> wrote:

> wayne burdick wrote
> > 2.8 kHz should give some improvement over a narrow filter on some types
> of
> > noise. Worth a try. Just temporarily tell the firmware that it's a little
> > bit wider than your narrow filter, then use the WIDTH control to switch
> > between narrow and wide. Re-optimize the NB settings each time.
>
> I've been having a problem with a pulse type electric fencer (not the 60 Hz
> cycling buzz type which is impossible to cure with a blanker). Most
> radios'
> NBs deal effectively with pulses but for some reason (firmware change) my
> K3
> (#4717) is not. I decided to try Wayne's suggestion even though I only
> have
> the 2.7 kHz stock filter.
>
> The problem with Wayne's suggestion is that the K3 Utility will not accept
> 0.45 as a valid width for the 2.7 kHz filter because it is used for TX on
> CW/SSB and bandwidths <2.7 kHz are not allowed. Is there a workaround for
> this or am I doing something wrong?
>
> 73, Bill W4ZV
>
>
>
>
> --
> View this message in context:
> http://elecraft.365791.n2.nabble.com/K3-K3S-noise-blanker-performance-greatly-enhanced-at-my-QTH-need-testers-tp7613491p7613631.html
> Sent from the Elecraft mailing list archive at Nabble.com.
> ______________________________________________________________
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David Woolley (E.L)

Re: K3/K3S noise blanker performance greatly enhanced (at my QTH) -- need testers

In reply to this post by drewko

Noise reduction is a difficult problem and hearing aid manufacturers
have been trying to solve it for the last couple of decades.

One important point to note is that noise reduction is normally aimed at
reducing subjective noise and therefore reducing fatigue. Generally
what you are doing is actually recognising signal, then suppressing
those frequencies that are not conveying the signal. The noise on the
same frequencies as important parts of the signal still gets through.

You cannot remove noise unless you have first identified the signal, so
you cannot remove the noise that is masking an unknown signal.

The simplest noise reduction is a narrow band CW filter! The ultimate
noise reduction for CW would be to decode the signal, and regenerate it,
but that is currently only possible for signals that are already clean
an well formed.

Decode and recreate might be the ultimate solution for hearing aids, as
well.

--
David Woolley
Owner K2 06123

On 06/02/16 03:35, drewko wrote:
> I'm glad that noise solutions are being investigated. I think advances
> in NR/NB would be of more importance to many hams than close-in dynamic
> range, however useful the improvement in those attention-getting figures
> are. On a day to day basis noise is the top culprit for many of us.

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Gary Smith-2

Re: K3/K3S noise blanker performance greatly enhanced (at my QTH) -- need testers

David,

My father made something like that many
years ago. I'm thinking it is still here,
one of the many things yet to be uncovered
in his shack. Its in a blue plastic
enclosure, I'll know it when I see it.

He'd been a ham since 36 or 37 and he was
an EE, worked for General Dynamics in
their Sub division. He made an audio
filter for CW that managed to not have
noise affect the generated signal unless
the signal was garbled past
intelligibility, in which case no tone was
generated. I remember him remarking how
much more narrow the audio was and that it
was narrower by far than the narrowest CW
filter on his Collins.

It would regenerate that garbled CW tone
into a regenerated tone devoid of any
noise in the background. It had to have a
decent enough sound to work with but I
remember hearing the pure generated note
being free of any garbage with it.

73,
Gary
KA1J

> The simplest noise reduction is a narrow band CW filter! The ultimate
> noise reduction for CW would be to decode the signal, and regenerate it,
> but that is currently only possible for signals that are already clean
> an well formed.
>
> Decode and recreate might be the ultimate solution for hearing aids, as
> well.
>
> --
> David Woolley
> Owner K2 06123

NK7Z

Re: K3/K3S noise blanker performance greatly enhanced (at my QTH) -- need testers

In reply to this post by David Woolley (E.L)

Isn't that how the Transporter in Star Trek works? :)
--
73's, and thanks,
Dave

For software/hardware reviews see:
http://www.nk7z.net

For MixW support see:
https://groups.yahoo.com/neo/groups/mixw/info

For SSTV help see:
http://groups.yahoo.com/neo/groups/MM-SSTV/info

On Sun, 2016-02-07 at 00:03 +0000, David Woolley wrote:

> Noise reduction is a difficult problem and hearing aid manufacturers
> have been trying to solve it for the last couple of decades.
>
> One important point to note is that noise reduction is normally aimed
> at
> reducing subjective noise and therefore reducing fatigue.  Generally
> what you are doing is actually recognising signal, then suppressing
> those frequencies that are not conveying the signal.  The noise on
> the
> same frequencies as important parts of the signal still gets through.
>
> You cannot remove noise unless you have first identified the signal,
> so
> you cannot remove the noise that is masking an unknown signal.
>
> The simplest noise reduction is a narrow band CW filter!  The
> ultimate
> noise reduction for CW would be to decode the signal, and regenerate
> it,
> but that is currently only possible for signals that are already
> clean
> an well formed.
>
> Decode and  recreate might be the ultimate solution for hearing aids,
> as
> well.
>

Deni F5VJC

Re: K3/K3S noise blanker performance greatly enhanced (at my QTH) -- need testers

Well actually I prefer copying CW with a certain amount of noise present.
Pure tone, no noise CW, as from a practice oscillator or an S9++ signal
quickly becomes boring and I loose concentration(or something).
It's perhaps why I prefer to dig out weak signals (ESP) from the noise on
the band.
However I do really appreciate the tools available in the K3 to do this :)
APF works great if you really learn to use it.

Any one else?

73, Deni - F5VJC

On 7 February 2016 at 03:46, Dave Cole <[hidden email]> wrote:

> Isn't that how the Transporter in Star Trek works? :)
> --
> 73's, and thanks,
> Dave
>
> For software/hardware reviews see:
> http://www.nk7z.net
>
> For MixW support see:
> https://groups.yahoo.com/neo/groups/mixw/info
>
> For SSTV help see:
> http://groups.yahoo.com/neo/groups/MM-SSTV/info
>
>
>
> On Sun, 2016-02-07 at 00:03 +0000, David Woolley wrote:
> > Noise reduction is a difficult problem and hearing aid manufacturers
> > have been trying to solve it for the last couple of decades.
> >
> > One important point to note is that noise reduction is normally aimed
> > at
> > reducing subjective noise and therefore reducing fatigue. Generally
> > what you are doing is actually recognising signal, then suppressing
> > those frequencies that are not conveying the signal. The noise on
> > the
> > same frequencies as important parts of the signal still gets through.
> >
> > You cannot remove noise unless you have first identified the signal,
> > so
> > you cannot remove the noise that is masking an unknown signal.
> >
> > The simplest noise reduction is a narrow band CW filter! The
> > ultimate
> > noise reduction for CW would be to decode the signal, and regenerate
> > it,
> > but that is currently only possible for signals that are already
> > clean
> > an well formed.
> >
> > Decode and recreate might be the ultimate solution for hearing aids,
> > as
> > well.
> >
> ______________________________________________________________
> 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
> Message delivered to [hidden email]
>

Bill W4ZV

Re: K3/K3S noise blanker performance greatly enhanced (at my QTH) -- need testers

In reply to this post by john@kk9a.com

john@kk9a.com wrote

Even if this works for your noise, I wonder how well it will work using a
wide roofing filter in contest conditions.

Perhaps for RX testing only you can select a different narrower TX filter?

Definitely would not work in high activity contests, but fencer clicks would be buried in all the other mess anyway. ;-)

I do have a 2.1 in Main which I'll try the next time I experiment. Unfortunately I don't have that in Sub which precludes diversity, which I use for weak signals that the clicks bother. BTW you can NEVER select a narrower TX filter than 2.7/2.8 because the firmware/software will not allow it (even for CW). I know because I tried to do that years ago in an attempt to further cleanse my CW signal. Now the KSYN3A does a great job of that anyway.

When I do another experiment with the 2.1, I'll report the results here.

73, Bill W4ZV

Jerry Moore

Re: K3/K3S noise blanker performance greatly enhanced (at my QTH) -- need testers

In reply to this post by NK7Z

It uses the principal of Quantum Entanglement at its core.

Jerry Moore
CDXA, INDEXA, SKCC, Fists
AE4PB, K3S - S.N. 010324
http://www.qrz.com/db/AE4PB
An Amateur is - Considerate, Loyal, Progressive, Friendly, Balanced, and Patriotic.

-----Original Message-----
From: Elecraft [mailto:[hidden email]] On Behalf Of Dave Cole
Sent: Saturday, February 06, 2016 9:47 PM
To: [hidden email]
Subject: Re: [Elecraft] K3/K3S noise blanker performance greatly enhanced (at my QTH) -- need testers

Isn't that how the Transporter in Star Trek works? :)
--
73's, and thanks,
Dave

For software/hardware reviews see:
http://www.nk7z.net

For MixW support see:
https://groups.yahoo.com/neo/groups/mixw/info

For SSTV help see:
http://groups.yahoo.com/neo/groups/MM-SSTV/info

On Sun, 2016-02-07 at 00:03 +0000, David Woolley wrote:

> Noise reduction is a difficult problem and hearing aid manufacturers
> have been trying to solve it for the last couple of decades.
>
> One important point to note is that noise reduction is normally aimed
> at reducing subjective noise and therefore reducing fatigue.
> Generally what you are doing is actually recognising signal, then
> suppressing those frequencies that are not conveying the signal. The
> noise on the same frequencies as important parts of the signal still
> gets through.
>
> You cannot remove noise unless you have first identified the signal,
> so you cannot remove the noise that is masking an unknown signal.
>
> The simplest noise reduction is a narrow band CW filter! The ultimate
> noise reduction for CW would be to decode the signal, and regenerate
> it, but that is currently only possible for signals that are already
> clean an well formed.
>
> Decode and recreate might be the ultimate solution for hearing aids,
> as well.
>

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123