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

[wayne burdick]

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







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[wayne burdick]

I wasn't clear on this point: You don't need any new firmware to try the experiment. Just use K3 Utility to temporarily alter the bandwidth of the 6-kHz filter as explained in the setup instructions below.

In fact, you don't really even need K3 Utility. You can change the filter bandwidth using the CONFIG:FLx BW menu entry, where 'x' is the number assigned to your 6-kHz filter.

Wayne
N6KR


On Feb 3, 2016, at 7:03 PM, Wayne Burdick <[hidden email]> 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
>
>
>
>
>
>
>

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[Tim Tucker]

Wayne,

What is the difference in configuration to trying this on SSB? Do we make
the same settings change or change Filter 1 if we have the 13Khz filter?
And how are AM and FM affected?

I've got the type of noise you're referring to here from local plasma TV
interference...I'd love to try this on SSB.

On Wed, Feb 3, 2016 at 7:03 PM, Wayne Burdick <[hidden email]> 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]
>

--
Owner, worldwidedx.com
AE6LX, Amateur Radio
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[wayne burdick]

Hi Tim,

The 15 kHz filter may work for this purpose in SSB mode. Haven't tried it yet, so it's even more experimental. Still, if you're game, just set the bandwidth of the FM filter (always FL1, if it's present), to a bandwidth just a little over the bandwidth of your normal SSB filter. For example, if the SSB filter is 2.8 kHz, set the FM filter bandwidth to 2.9 kHz.

Remember the caveat: Widening the filter will allow more in-band interference to slip through, which may require that you reduce gain (RF GAIN, preamp, or attenuator).

AM and FM already use wide crystal filters, so the experimental technique I described will not offer any further improvement in these modes. It sure works well (for me, at least) in narrow modes.

Let me know what you find.

73,
Wayne
N6KR


Tim Tucker <[hidden email]> wrote:

> Wayne,
>
> What is the difference in configuration to trying this on SSB? Do we make
> the same settings change or change Filter 1 if we have the 13Khz filter?
> And how are AM and FM affected?
>
> I've got the type of noise you're referring to here from local plasma TV
> interference...I'd love to try this on SSB.



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[K9MA]

If I understand it correctly, reason for the wide crystal filter is that
a narrow filter stretches the noise pulses, making blanking
ineffective.  (The idea is to blank out the noise, without blanking out
a lot of the signal.)  The wide filter passes the narrow noise pulses to
the DSP, which can then blank them out like a hardware blanker.  The
result is passed to DSP bandpass filter.

I don't have the 6 kHz filter, but I'd like to know how well it works.  
One of my (few) disappointments with the K3 is the noise blanker, which
never seems very effective on line noise.  The conventional noise
blanker in my old FT-1000 can often reduce the noise dramatically, but
only when there are no strong signals nearby.   Alas, that means it
never works during contests.

Long, long ago, someone (Collins?) proposed using a second receiver to
control a noise blanker, with the second receiver tuned to a nearby
clear spot wide enough for a filter much wider than that of the primary
receiver, say 15 kHz.  That might be just outside the ham band, for
example.   Then the main receiver would retain its excellent immunity to
strong nearby signals.  Now, if the subreceiver in the K3/K3s could be
made to do that, I'd buy the 15 kHz filter instantly.

73,

Scott K9MA

--
Scott Ellington  K9MA
Madison, Wisconsin, USA

[hidden email]

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[Tim Tucker]

I did a quick 'n dirty cell phone video of the results of this on SSB.  You
NEED to use headphones to hear the difference because the cell recording
has crappy audio.  This test is done on 75 meters, dialed into a plasma TV
generating noise.  There is no intelligent signal present - just the noise
floor and the plasma tv.  In this test, I found that a DSP NB setting of
2-3 worked best - incidentally, is usually use 2-2 or 2-3 on a daily basis
but I've never been really happy with any of the NB settings.
Incidentally, I also tried it in the video with the AGC turned ON and that
had good results, as well.

I need to find an actual intelligible signal to do this on, but the
preliminary results are quite impressive.  I'd LOVE to have a DSP NB
setting that would activate this without having to permanently alter the
filter settings.  Here and watch for yourself

http://1drv.ms/1PTCo6y

Tim
AE6LX

On Wed, Feb 3, 2016 at 9:22 PM, Scott Ellington <[hidden email]> wrote:

> If I understand it correctly, reason for the wide crystal filter is that a
> narrow filter stretches the noise pulses, making blanking ineffective.
> (The idea is to blank out the noise, without blanking out a lot of the
> signal.)  The wide filter passes the narrow noise pulses to the DSP, which
> can then blank them out like a hardware blanker.  The result is passed to
> DSP bandpass filter.
>
> I don't have the 6 kHz filter, but I'd like to know how well it works.
> One of my (few) disappointments with the K3 is the noise blanker, which
> never seems very effective on line noise.  The conventional noise blanker
> in my old FT-1000 can often reduce the noise dramatically, but only when
> there are no strong signals nearby.   Alas, that means it never works
> during contests.
>
> Long, long ago, someone (Collins?) proposed using a second receiver to
> control a noise blanker, with the second receiver tuned to a nearby clear
> spot wide enough for a filter much wider than that of the primary receiver,
> say 15 kHz.  That might be just outside the ham band, for example.   Then
> the main receiver would retain its excellent immunity to strong nearby
> signals.  Now, if the subreceiver in the K3/K3s could be made to do that,
> I'd buy the 15 kHz filter instantly.
>
> 73,
>
> Scott K9MA
>
> --
> Scott Ellington  K9MA
> Madison, Wisconsin, USA
>
> [hidden email]
>
>
> ______________________________________________________________
> 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]
>

--
Owner, worldwidedx.com
AE6LX, Amateur Radio
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[Vic Rosenthal]

This is very interesting, because where I live there are sometimes strong noise sources perhaps from OTH radar or other applications which take out big chunks of a band.
The technique described is suboptimal because you sacrifice the roofing filter function in order to narrow the blanker's passband. Is there some way to do this without interfering with the filters?
My guess is that it would require a hardware modification. But maybe it could be a plugin replacement for the noise blanker board?
Noise is a huge problem for many of us and it will only get worse in the future. Any improvement to anti-noise features would be a big advantage over the competition.

Vic 4X6GP/K2VCO

> On 4 Feb 2016, at 5:03 AM, Wayne Burdick <[hidden email]> 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
>
>
>
>
>
>
>
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[Wes (N7WS)]

Maybe this is an opportunity to rant about the K3/K3S noise blanker.

Back on 12/8/15 K2AV wrote: "To those trying to get rid of a certain noise,
remember that there are 21+21+(21x21) combinations of IF and DSP blanking.
That's 483 combinations, not counting variations with preamp/normal/atten settings."

Now we're adding more?

At the time, I composed a message that I failed to send.  It follows:

"Personally, I don't want to "tinker" with 483 possible adjustments.  As I've
said before,with a radio with this much computing horsepower and the design
talent at Elecraft I fail to understand why blanking thresholds and duration
aren't nearly automatic.

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.

The K3 blanker is okay.  Although I no longer have it around to compare to, I
designed a pretty effective one in 1977.  Perhaps the best blanker I've run
across was in a lowly Yaesu FT221R 2-meter multimode.  The worst was in my
TS870SAT that otherwise was a good performer and had great ergonomics.  I've
said more than once that Kenwood wasted panel space putting in a control for the
noise blanker."

End of rant.  Eric can close the thread now:-)


On 2/3/2016 8:03 PM, 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
>
>
>

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[KV5J]

Diddo for me WES

Keith, KV5J

[Bob McGraw - K4TAX]

I've found quite a number of articles discussing noise blankers and the
implementation of such.   From my experience with radios on the desk,
past and present, the hardware noise blanker works quite well.  On the
other hand, DSP/software noise blankers have always been found to be
marginal.

It seems we are insisting on tighter and tighter bandwidths {filters} to
fight QRM.  While at the same time, the use of a tighter the filter has
the adverse effect that causes the noise pulse to be fattened.    This
is what Wayne was discussing in his recent post.  In another approach,
use a wide filter ahead of the NB thus it can become more effective on
blanking.  Wide pulses when blanked will punch holes in the audio.

There's a lot of history with Collins Radio and the implementation of
noise blanking methods.  None of these use DSP schemes and in one
system, a separate antenna was used to feed noise pulses to the blanker
circuit.   I suggest one research the topic in this vein. One of my
current radios on the desk uses a hardware noise blanker while the other
one uses a DSP/software blanking system.  Both radios are from the same
company.  It is amazing how much better the hardware noise blanker
performs over the two radios which use DSP or software noise blankers.

73
Bob, K4TAX
K3S, s/n 10163



On 2/4/2016 8:45 AM, Wes (N7WS) wrote:

> Maybe this is an opportunity to rant about the K3/K3S noise blanker.
>
> Back on 12/8/15 K2AV wrote: "To those trying to get rid of a certain
> noise, remember that there are 21+21+(21x21) combinations of IF and
> DSP blanking. That's 483 combinations, not counting variations with
> preamp/normal/atten settings."
>
> Now we're adding more?
>
> At the time, I composed a message that I failed to send.  It follows:
>
> "Personally, I don't want to "tinker" with 483 possible adjustments.  
> As I've said before,with a radio with this much computing horsepower
> and the design talent at Elecraft I fail to understand why blanking
> thresholds and duration aren't nearly automatic.
>
> 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.
>
> The K3 blanker is okay.  Although I no longer have it around to
> compare to, I designed a pretty effective one in 1977.  Perhaps the
> best blanker I've run across was in a lowly Yaesu FT221R 2-meter
> multimode.  The worst was in my TS870SAT that otherwise was a good
> performer and had great ergonomics.  I've said more than once that
> Kenwood wasted panel space putting in a control for the noise blanker."
>
> End of rant.  Eric can close the thread now:-)
>

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[wayne burdick]

On Feb 3, 2016, at 11:29 PM, Vic Rosenthal <[hidden email]> wrote:

> This is very interesting, because where I live there are sometimes strong noise sources perhaps from OTH radar or other applications which take out big chunks of a band.


Hi Vic,

Let me emphasize that this is an experiment. Please send me your results if you do try it.

tnx
Wayne
N6KR



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[wayne burdick]

Tim,

Based on your positive results with SSB and the 15-kHz filter, I'm going to give it a try.

Thanks,
Wayne
N6KR


On Feb 3, 2016, at 10:56 PM, Tim Tucker <[hidden email]> wrote:

> I did a quick 'n dirty cell phone video of the results of this on SSB.  You
> NEED to use headphones to hear the difference because the cell recording
> has crappy audio.  This test is done on 75 meters, dialed into a plasma TV
> generating noise.  There is no intelligent signal present - just the noise
> floor and the plasma tv.  In this test, I found that a DSP NB setting of
> 2-3 worked best - incidentally, is usually use 2-2 or 2-3 on a daily basis
> but I've never been really happy with any of the NB settings.
> Incidentally, I also tried it in the video with the AGC turned ON and that
> had good results, as well.
>
> I need to find an actual intelligible signal to do this on, but the
> preliminary results are quite impressive.  I'd LOVE to have a DSP NB
> setting that would activate this without having to permanently alter the
> filter settings.  Here and watch for yourself
>
> http://1drv.ms/1PTCo6y
>
> Tim
> AE6LX

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[Phil Hystad-3]

The recent comments regarding Wayne’s new Noise Blanker experiment reminded me of something I wanted to suggest awhile back but forgot all about it.

This has to do with Macros and command sequences used to program or alter some specific setting in a temporary (maybe) way.  Many of these are posted here as well as found on some web sites including Elecraft.

But, there is something missing that would be nice.  And, that is a documented library hosted on Elecraft’s web site as well as a utility program feature to automatically download and manage the macro programs.

As a library, the documentation should be embedded in the Macro file itself per a standard format that declares the purpose (brief abstract), more detailed user instructions, and any known side effects.  Also, author’s name and date and maybe a revision history.

The utility programs would include a new feature to download (maybe abstracts or complete macro file) and list available macro programs displaying the brief abstract on the display.  The utility program would allow the user to select macros for download that copy them to a known location on the user’s computer managed by the utility program.  Also, this new feature set would support the loading of the macro to the K3/K3S/KX3.  Actually, a very nice “extra” would be to undo the macro act.  Of course, this could get complicated since a Macro can do anything and many things that should not be done.  But, one way to undo is to automatically save and then allow restoration of the rig settings, say in some kind of test mode.  Of course, this could be done by the user but it might be faster to do it as part of a test sequence supported by the utility program.

It seems like the only complicate part of this process is setting up a repository and managing it in a way that ensures the integrity of the standards: documentation, layout, and anything else.  The enhancements to the utility programs do not seem to be all that hard to do (I am a retired programmer of about 50 years programming experience).

There could be a network of volunteers that accept the new macros to be included and they test and vet those macros per the definition of purpose and the standards set forth for this repository.

73, phil, K7PEH


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[NK7Z]

That is an absolutely wonderful idea Phil!!!  I would love to be in the
macro testing volunteer group if this happens...
--
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 Thu, 2016-02-04 at 09:17 -0800, Phil Hystad wrote:

> The recent comments regarding Wayne’s new Noise Blanker experiment
> reminded me of something I wanted to suggest awhile back but forgot
> all about it.
>
> This has to do with Macros and command sequences used to program or
> alter some specific setting in a temporary (maybe) way.  Many of
> these are posted here as well as found on some web sites including
> Elecraft.
>
> But, there is something missing that would be nice.  And, that is a
> documented library hosted on Elecraft’s web site as well as a utility
> program feature to automatically download and manage the macro
> programs.
>
> As a library, the documentation should be embedded in the Macro file
> itself per a standard format that declares the purpose (brief
> abstract), more detailed user instructions, and any known side
> effects.  Also, author’s name and date and maybe a revision history.
>
> The utility programs would include a new feature to download (maybe
> abstracts or complete macro file) and list available macro programs
> displaying the brief abstract on the display.  The utility program
> would allow the user to select macros for download that copy them to
> a known location on the user’s computer managed by the utility
> program.  Also, this new feature set would support the loading of the
> macro to the K3/K3S/KX3.  Actually, a very nice “extra” would be to
> undo the macro act.  Of course, this could get complicated since a
> Macro can do anything and many things that should not be done.  But,
> one way to undo is to automatically save and then allow restoration
> of the rig settings, say in some kind of test mode.  Of course, this
> could be done by the user but it might be faster to do it as part of
> a test sequence supported by the utility program.
>
> It seems like the only complicate part of this process is setting up
> a repository and managing it in a way that ensures the integrity of
> the standards: documentation, layout, and anything else.  The
> enhancements to the utility programs do not seem to be all that hard
> to do (I am a retired programmer of about 50 years programming
> experience).
>
> There could be a network of volunteers that accept the new macros to
> be included and they test and vet those macros per the definition of
> purpose and the standards set forth for this repository.
>
> 73, phil, K7PEH
>
>
> ______________________________________________________________
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[N1EU]

Since macros are only text files, I personally have no need of fancy
functionality in a library or utility.  The current Elecraft K3 utility
works beautifully.

So for me, a simple Web site (or shared Google doc) listing macro examples
is all the functionality that I think is needed.

73, Barry N1EU

On Thu, Feb 4, 2016 at 12:17 PM, Phil Hystad <[hidden email]> wrote:

> The recent comments regarding Wayne’s new Noise Blanker experiment
> reminded me of something I wanted to suggest awhile back but forgot all
> about it.
>
> This has to do with Macros and command sequences used to program or alter
> some specific setting in a temporary (maybe) way.  Many of these are posted
> here as well as found on some web sites including Elecraft.
>
> But, there is something missing that would be nice.  And, that is a
> documented library hosted on Elecraft’s web site as well as a utility
> program feature to automatically download and manage the macro programs.
>
> As a library, the documentation should be embedded in the Macro file
> itself per a standard format that declares the purpose (brief abstract),
> more detailed user instructions, and any known side effects.  Also,
> author’s name and date and maybe a revision history.
>
> The utility programs would include a new feature to download (maybe
> abstracts or complete macro file) and list available macro programs
> displaying the brief abstract on the display.  The utility program would
> allow the user to select macros for download that copy them to a known
> location on the user’s computer managed by the utility program.  Also, this
> new feature set would support the loading of the macro to the K3/K3S/KX3.
> Actually, a very nice “extra” would be to undo the macro act.  Of course,
> this could get complicated since a Macro can do anything and many things
> that should not be done.  But, one way to undo is to automatically save and
> then allow restoration of the rig settings, say in some kind of test mode.
> Of course, this could be done by the user but it might be faster to do it
> as part of a test sequence supported by the utility program.
>
> It seems like the only complicate part of this process is setting up a
> repository and managing it in a way that ensures the integrity of the
> standards: documentation, layout, and anything else.  The enhancements to
> the utility programs do not seem to be all that hard to do (I am a retired
> programmer of about 50 years programming experience).
>
> There could be a network of volunteers that accept the new macros to be
> included and they test and vet those macros per the definition of purpose
> and the standards set forth for this repository.
>
> 73, phil, K7PEH
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>
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[N7US]

Why not upload them to the Elecraft_K3 Yahoo Group files area?

https://groups.yahoo.com/neo/groups/Elecraft_K3/files

I and others uploaded several K3 user-defined controls for DXLab's Commander rig control module to the DXLab Yahoo Group Files area a few years ago.  Commander allow many more macros than the buttons on the radio do, and they can be executed by pressing a mouse button or an F-key.  I think it's pretty easy to create them in Commander.

You can download them and use them without rekeying them.

Information on Commander user-defined controls (sequences and sliders) is available at:
http://www.dxlabsuite.com/commander/Help/CommandSequences.htm .

73, Jim N7US



-----Original Message-----


Since macros are only text files, I personally have no need of fancy functionality in a library or utility.  The current Elecraft K3 utility works beautifully.

So for me, a simple Web site (or shared Google doc) listing macro examples is all the functionality that I think is needed.

73, Barry N1EU

On Thu, Feb 4, 2016 at 12:17 PM, Phil Hystad <[hidden email]> wrote:

> The recent comments regarding Wayne’s new Noise Blanker experiment
> reminded me of something I wanted to suggest awhile back but forgot
> all about it.
>
> This has to do with Macros and command sequences used to program or
> alter some specific setting in a temporary (maybe) way.  Many of these
> are posted here as well as found on some web sites including Elecraft.
>
> But, there is something missing that would be nice.  And, that is a
> documented library hosted on Elecraft’s web site as well as a utility
> program feature to automatically download and manage the macro programs.
>
> As a library, the documentation should be embedded in the Macro file
> itself per a standard format that declares the purpose (brief
> abstract), more detailed user instructions, and any known side
> effects.  Also, author’s name and date and maybe a revision history.
>
> The utility programs would include a new feature to download (maybe
> abstracts or complete macro file) and list available macro programs
> displaying the brief abstract on the display.  The utility program
> would allow the user to select macros for download that copy them to a
> known location on the user’s computer managed by the utility program.  
> Also, this new feature set would support the loading of the macro to the K3/K3S/KX3.
> Actually, a very nice “extra” would be to undo the macro act.  Of
> course, this could get complicated since a Macro can do anything and
> many things that should not be done.  But, one way to undo is to
> automatically save and then allow restoration of the rig settings, say in some kind of test mode.
> Of course, this could be done by the user but it might be faster to do
> it as part of a test sequence supported by the utility program.
>
> It seems like the only complicate part of this process is setting up a
> repository and managing it in a way that ensures the integrity of the
> standards: documentation, layout, and anything else.  The enhancements
> to the utility programs do not seem to be all that hard to do (I am a
> retired programmer of about 50 years programming experience).
>
> There could be a network of volunteers that accept the new macros to
> be included and they test and vet those macros per the definition of
> purpose and the standards set forth for this repository.
>
> 73, phil, K7PEH

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[Wes (N7WS)]

The Collins noise receiver operated around 40 Megacycles, as we said in those days.

My late friend and "Elmer", Lee, W7UVR was one of the first kids on the block to
have a 136C-1 blanker to use with his 75A-4.

Since he was quite well off financially I never understood why he lived in the
same neighborhood my parents and I lived in, particularly since he had a power
line practically in his back yard, but he did.  Because of this, he couldn't
hear anything, so he became an Official Bulletin Station for ARRL and he built
the mobile rig to end all mobile rigs. (In AM days, a 4-1000A high level
modulated by four 813s.)  See: http://www.k0bg.com/gallery2/main.php?g2_itemId=1039

But the Collins noise blanker made all the difference.

On 2/4/2016 8:48 AM, Bob McGraw K4TAX wrote:
> [snip]
>
> There's a lot of history with Collins Radio and the implementation of noise
> blanking methods.  None of these use DSP schemes and in one system, a separate
> antenna was used to feed noise pulses to the blanker circuit.

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[Dick Dickinson]

The Collins 136C-1 Noise Blanker seems interesting.

 

73,

Dick - KA5KKT

  _____  

The Collins noise receiver operated around 40 Megacycles, as we said in
those days.

 

My late friend and "Elmer", Lee, W7UVR was one of the first kids on the
block to

have a 136C-1 blanker to use with his 75A-4.  <snip>

 

 

 

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[W5RDW]

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

[Bob McGraw - K4TAX]

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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