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Next Question: DATA A with K3s and Fldigi

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k4vd

Next Question: DATA A with K3s and Fldigi

My first PSK-31 contact seemed to go very well. I simply adjusted the MIC
level (Line) until there was 5-7 ALC bars. The adjustment was quite smooth.

Then I went off and did other things and I'm concerned I changed something.
Now I have to turn the level way way down on the USB Audio CODEC (-16.4
dB). Then I add another -3 dB using fldigi. Finally, I adjust the Mic to
Line = 17. The Mic adjustment isn't smooth.

The major change was the addition of the KAT500 and KPA500 (stby) and I'm
wondering if either I messed up a setting or maybe created an opportunity
for some RF feedback that's affecting the audio.

At this point, I don't know how to confirm the signal is clean (especially
PSK-31). I've only had one report of a possible problem and a number of
reports of "things look good" so I'm calling that a wash.

I found nothing in the instructions that told me to drop the level of the
USB Audio CODEC and -16.4 dB seems like a big drop. The CODEC is set for 16
bit, 48000 Hz.

Am I worrying about nothing? Is your setup with fldigi and DATA A using the
K3s's internal sound card similar?

Thanks for your patience.

73,
Kev N4TT
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Bob McGraw - K4TAX

Re: Next Question: DATA A with K3s and Fldigi

Kev:

First the ALC indication should be, no.... must be, 4 bars solid and the
5th bar flickering.    To monitor your signal, use the MON function of
the K3S. It should sound VERY clean. If there is buzz, growl, humm or
anything besides pure tone, there are issues to be resolved. Check all
PL-259 connectors in the signal path to assure they are very tight. I
use a pair of 4" Channel lock pliers to snug mine.

As to levels -18 dB is 30% for the SPKR level from the computer. That is
what I use. Then the level adjustment {lower right corner} in FLDIGI is
running -10 dB and the Line Gain on my K3S is running at 30.     Then
set the PWR value on the radio to the value of your choice, I normally
run 50 watts without the KPA500. With the KPA500 I run 300 to 350
watts.   All of these numbers work for WSJT-X / FT-8 as well.

As to things "looking good", I rely largely on the software and IMD
reports.    I also have a 2nd receiver and computer where I can monitor
my own signal if need be.

Seems you just need to tweak levels a bit to get things in a more normal
and balanced level condition.

73

Bob, K4TAX

On 6/17/2019 12:50 AM, Kevin, N4TT wrote:

> My first PSK-31 contact seemed to go very well. I simply adjusted the MIC
> level (Line) until there was 5-7 ALC bars. The adjustment was quite smooth.
>
> Then I went off and did other things and I'm concerned I changed something.
> Now I have to turn the level way way down on the USB Audio CODEC (-16.4
> dB). Then I add another -3 dB using fldigi. Finally, I adjust the Mic to
> Line = 17. The Mic adjustment isn't smooth.
>
> The major change was the addition of the KAT500 and KPA500 (stby) and I'm
> wondering if either I messed up a setting or maybe created an opportunity
> for some RF feedback that's affecting the audio.
>
> At this point, I don't know how to confirm the signal is clean (especially
> PSK-31). I've only had one report of a possible problem and a number of
> reports of "things look good" so I'm calling that a wash.
>
> I found nothing in the instructions that told me to drop the level of the
> USB Audio CODEC and -16.4 dB seems like a big drop. The CODEC is set for 16
> bit, 48000 Hz.
>
> Am I worrying about nothing? Is your setup with fldigi and DATA A using the
> K3s's internal sound card similar?
>
> Thanks for your patience.
>
> 73,
> Kev N4TT
> ______________________________________________________________
> 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]
>

Conrad PA5Y

Re: Next Question: DATA A with K3s and Fldigi

Historically there were all kinds of low level artefacts produced by Windows audio algorithms, including the volume control. This was caused by insufficient precision leading to truncation artefacts. I have not tested it for a while and so it may no longer be the case. The result when I did test it was spectral smearing and some AM on what should be a constant envelope signal. I trust the power control in WSJT-X far more than that from the Windows mixer. These effects only really matter during weak signal conditions when your TX signal is on or near the noise floor. at the receiving station However they do make your signal wider.

Also be careful how you vary power, reducing audio carelessly will invariably decrease the signal to noise on your TX signal which will also affect a stations ability to receive you.

My K3S arrives this week and I will make some tests to see exactly what happens with TX composite noise when power is reduced with the power control and by reducing audio drive from the PC. Unless someone else has measured this already?

73

Conrad PA5Y

________________________________
From: [hidden email] <[hidden email]> on behalf of Bob McGraw K4TAX <[hidden email]>
Sent: 17 June 2019 15:13
To: [hidden email]
Subject: Re: [Elecraft] Next Question: DATA A with K3s and Fldigi

Kev:

First the ALC indication should be, no.... must be, 4 bars solid and the
5th bar flickering. To monitor your signal, use the MON function of
the K3S. It should sound VERY clean. If there is buzz, growl, humm or
anything besides pure tone, there are issues to be resolved. Check all
PL-259 connectors in the signal path to assure they are very tight. I
use a pair of 4" Channel lock pliers to snug mine.

As to levels -18 dB is 30% for the SPKR level from the computer. That is
what I use. Then the level adjustment {lower right corner} in FLDIGI is
running -10 dB and the Line Gain on my K3S is running at 30. Then
set the PWR value on the radio to the value of your choice, I normally
run 50 watts without the KPA500. With the KPA500 I run 300 to 350
watts. All of these numbers work for WSJT-X / FT-8 as well.

As to things "looking good", I rely largely on the software and IMD
reports. I also have a 2nd receiver and computer where I can monitor
my own signal if need be.

Seems you just need to tweak levels a bit to get things in a more normal
and balanced level condition.

73

Bob, K4TAX

On 6/17/2019 12:50 AM, Kevin, N4TT wrote:

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Don Wilhelm

Re: Next Question: DATA A with K3s and Fldigi

Conrad and all,

The POWER control in WSJT-X is a misnomer. It is actually an audio
level control. Do NOT use it to control the power with an Elecraft
transceiver - set the audio correctly and use the power knob to control
the power.

While other amateur transceivers can be made to control the power by
varying the audio level, that can be disastrous for Elecraft transceiver
Power Control. Read the relevant article on my website www.w3fpr.com
for a full explanation.

Set the WSJT-X POWER control for 30% to 50% and do the same for the
soundcard control in Windows Mixer, then set the LINE IN gain in the
K3/S to somewhere near mid-range. By manipulation of those 3 audio
level controls, you should be able to achieve the 'magic' indication of
4 bars solid on the ALC meter with the 5th bar flashing - that is the
"NO ALC" point for the K3/S, KX3, and KX2 transeivers. The lower 4 bars
of the "ALC" meter are there as an aid for setting the audio levels.
Set the desired power output with the POWER knob - do NOT vary the audio
level.

73,
Don W3FPR

On 6/17/2019 9:38 AM, Conrad PA5Y wrote:
>
> Historically there were all kinds of low level artefacts produced by Windows audio algorithms, including the volume control. This was caused by insufficient precision leading to truncation artefacts. I have not tested it for a while and so it may no longer be the case. The result when I did test it was spectral smearing and some AM on what should be a constant envelope signal. I trust the power control in WSJT-X far more than that from the Windows mixer. These effects only really matter during weak signal conditions when your TX signal is on or near the noise floor. at the receiving station However they do make your signal wider.
>
> Also be careful how you vary power, reducing audio carelessly will invariably decrease the signal to noise on your TX signal which will also affect a stations ability to receive you.
>
> My K3S arrives this week and I will make some tests to see exactly what happens with TX composite noise when power is reduced with the power control and by reducing audio drive from the PC. Unless someone else has measured this already?
>
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Conrad PA5Y

Re: Next Question: DATA A with K3s and Fldigi

Don of course it is not a power control, that is obvious to me.

I am very fortunate to have a lot of RF and Audio test equipment available both at home and at work so I will measure what works best and try to understand why. I will be happy to share my findings. I will of course read your article. I am loathe to use the Windows audio mixer, I would rather use an external passive attenuator. Maybe the Windows mixer has improved, I need to check that with an audio analyser. It used to be awful so I built an external passive attenuator some years ago.

I will be interested to see what happens to the K3S TX composite noise when the power control is used. There is a certain very popular radio where the AM noise comes up by 20 dB when the power is reduced from 100W to 30W. I would be really pleased if the K3S power control works properly!

I bought the K3S purely for its TX PN performance.

73

Conrad PA5Y
________________________________
From: Don Wilhelm <[hidden email]>
Sent: 17 June 2019 16:03:02
To: Conrad PA5Y; [hidden email]
Subject: Re: [Elecraft] Next Question: DATA A with K3s and Fldigi

Conrad and all,

The POWER control in WSJT-X is a misnomer. It is actually an audio
level control. Do NOT use it to control the power with an Elecraft
transceiver - set the audio correctly and use the power knob to control
the power.

While other amateur transceivers can be made to control the power by
varying the audio level, that can be disastrous for Elecraft transceiver
Power Control. Read the relevant article on my website www.w3fpr.com<http://www.w3fpr.com>
for a full explanation.

Set the WSJT-X POWER control for 30% to 50% and do the same for the
soundcard control in Windows Mixer, then set the LINE IN gain in the
K3/S to somewhere near mid-range. By manipulation of those 3 audio
level controls, you should be able to achieve the 'magic' indication of
4 bars solid on the ALC meter with the 5th bar flashing - that is the
"NO ALC" point for the K3/S, KX3, and KX2 transeivers. The lower 4 bars
of the "ALC" meter are there as an aid for setting the audio levels.
Set the desired power output with the POWER knob - do NOT vary the audio
level.

73,
Don W3FPR

On 6/17/2019 9:38 AM, Conrad PA5Y wrote:
>
> Historically there were all kinds of low level artefacts produced by Windows audio algorithms, including the volume control. This was caused by insufficient precision leading to truncation artefacts. I have not tested it for a while and so it may no longer be the case. The result when I did test it was spectral smearing and some AM on what should be a constant envelope signal. I trust the power control in WSJT-X far more than that from the Windows mixer. These effects only really matter during weak signal conditions when your TX signal is on or near the noise floor. at the receiving station However they do make your signal wider.
>
> Also be careful how you vary power, reducing audio carelessly will invariably decrease the signal to noise on your TX signal which will also affect a stations ability to receive you.
>
> My K3S arrives this week and I will make some tests to see exactly what happens with TX composite noise when power is reduced with the power control and by reducing audio drive from the PC. Unless someone else has measured this already?
>
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

Don Wilhelm

Re: Next Question: DATA A with K3s and Fldigi

Conrad,

Do check and adjust the Windows soundcard controls to mid-range. When
set to extremes, it can cause clipping and distortion.

With the K3S, the internal soundcard will identify as USB AUDIO CODEC.

73,
Don W3FPR

On 6/17/2019 11:21 AM, Conrad PA5Y wrote:

> Don of course it is not a power control, that is obvious to me.
>
> I am very fortunate to have a lot of RF and Audio test equipment
> available both at home and at work so I will measure what works best
> and try to understand why. I will be happy to share my findings. I
> will of course read your article. I am loathe to use the Windows audio
> mixer, I would rather use an external passive attenuator. Maybe the
> Windows mixer has improved, I need to check that with an audio
> analyser. It used to be awful so I built an external passive
> attenuator some years ago.
>
> I will be interested to see what happens to the K3S TX composite noise
> when the power control is used. There is a certain very popular radio
> where the AM noise comes up by 20 dB when the power is reduced from
> 100W to 30W. I would be really pleased if the K3S power control works
> properly!
>
> I bought the K3S purely for its TX PN performance.
>
> 73
>
> Conrad PA5Y
> ------------------------------------------------------------------------
> *From:* Don Wilhelm <[hidden email]>
> *Sent:* 17 June 2019 16:03:02
> *To:* Conrad PA5Y; [hidden email]
> *Subject:* Re: [Elecraft] Next Question: DATA A with K3s and Fldigi
> Conrad and all,
>
> The POWER control in WSJT-X is a misnomer. It is actually an audio
> level control. Do NOT use it to control the power with an Elecraft
> transceiver - set the audio correctly and use the power knob to control
> the power.
>
> While other amateur transceivers can be made to control the power by
> varying the audio level, that can be disastrous for Elecraft transceiver
> Power Control. Read the relevant article on my website www.w3fpr.com
> <http://www.w3fpr.com>
> for a full explanation.
>
> Set the WSJT-X POWER control for 30% to 50% and do the same for the
> soundcard control in Windows Mixer, then set the LINE IN gain in the
> K3/S to somewhere near mid-range. By manipulation of those 3 audio
> level controls, you should be able to achieve the 'magic' indication of
> 4 bars solid on the ALC meter with the 5th bar flashing - that is the
> "NO ALC" point for the K3/S, KX3, and KX2 transeivers. The lower 4 bars
> of the "ALC" meter are there as an aid for setting the audio levels.
> Set the desired power output with the POWER knob - do NOT vary the audio
> level.
>
> 73,
> Don W3FPR
>
> On 6/17/2019 9:38 AM, Conrad PA5Y wrote:
> >
> > Historically there were all kinds of low level artefacts produced by
> Windows audio algorithms, including the volume control. This was
> caused by insufficient precision leading to truncation artefacts. I
> have not tested it for a while and so it may no longer be the case.
> The result when I did test it was spectral smearing and some AM on
> what should be a constant envelope signal. I trust the power control
> in WSJT-X far more than that from the Windows mixer. These effects
> only really matter during weak signal conditions when your TX signal
> is on or near the noise floor. at the receiving station However they
> do make your signal wider.
> >
> > Also be careful how you vary power, reducing audio carelessly will
> invariably decrease the signal to noise on your TX signal which will
> also affect a stations ability to receive you.
> >
> > My K3S arrives this week and I will make some tests to see exactly
> what happens with TX composite noise when power is reduced with the
> power control and by reducing audio drive from the PC. Unless someone
> else has measured this already?
> >

Conrad PA5Y

Re: Next Question: DATA A with K3s and Fldigi

Don, it depends on the hardware. I would be very surprised if the Audio codec used in the K3S can reach full scale with the windows mixer at max. I expect that it is limited to -1dB FS. Also I believe that there are further limits imposed i WSJT-X. Therefore there should be no reason for clipping to occur in the CODEC. I expect that there is sufficient range in the mic gain (or whatever it is called) on the K3S. This gives the input signal the maximum SNR which is the socially responsible thing to do.

Until I have checked the behaviour of the windows mixer with the CODEC I will not be using it. As I have said previously I don't trust the windows mixer not to degrade the audio due This may well have been resolved but historically was of concern.

I think that I will decide what to do when I have made some proper measurements. It's not that I don't believe you, I just like to check things for myself.

73

Conrad PA5Y

________________________________
From: Don Wilhelm <[hidden email]>
Sent: 17 June 2019 17:31
To: Conrad PA5Y; [hidden email]
Subject: Re: [Elecraft] Next Question: DATA A with K3s and Fldigi

Conrad,

Do check and adjust the Windows soundcard controls to mid-range. When
set to extremes, it can cause clipping and distortion.

With the K3S, the internal soundcard will identify as USB AUDIO CODEC.

73,
Don W3FPR

On 6/17/2019 11:21 AM, Conrad PA5Y wrote:

> Don of course it is not a power control, that is obvious to me.
>
> I am very fortunate to have a lot of RF and Audio test equipment
> available both at home and at work so I will measure what works best
> and try to understand why. I will be happy to share my findings. I
> will of course read your article. I am loathe to use the Windows audio
> mixer, I would rather use an external passive attenuator. Maybe the
> Windows mixer has improved, I need to check that with an audio
> analyser. It used to be awful so I built an external passive
> attenuator some years ago.
>
> I will be interested to see what happens to the K3S TX composite noise
> when the power control is used. There is a certain very popular radio
> where the AM noise comes up by 20 dB when the power is reduced from
> 100W to 30W. I would be really pleased if the K3S power control works
> properly!
>
> I bought the K3S purely for its TX PN performance.
>
> 73
>
> Conrad PA5Y
> ------------------------------------------------------------------------
> *From:* Don Wilhelm <[hidden email]>
> *Sent:* 17 June 2019 16:03:02
> *To:* Conrad PA5Y; [hidden email]
> *Subject:* Re: [Elecraft] Next Question: DATA A with K3s and Fldigi
> Conrad and all,
>
> The POWER control in WSJT-X is a misnomer. It is actually an audio
> level control. Do NOT use it to control the power with an Elecraft
> transceiver - set the audio correctly and use the power knob to control
> the power.
>
> While other amateur transceivers can be made to control the power by
> varying the audio level, that can be disastrous for Elecraft transceiver
> Power Control. Read the relevant article on my website www.w3fpr.com<http://www.w3fpr.com>
> <http://www.w3fpr.com>
> for a full explanation.
>
> Set the WSJT-X POWER control for 30% to 50% and do the same for the
> soundcard control in Windows Mixer, then set the LINE IN gain in the
> K3/S to somewhere near mid-range. By manipulation of those 3 audio
> level controls, you should be able to achieve the 'magic' indication of
> 4 bars solid on the ALC meter with the 5th bar flashing - that is the
> "NO ALC" point for the K3/S, KX3, and KX2 transeivers. The lower 4 bars
> of the "ALC" meter are there as an aid for setting the audio levels.
> Set the desired power output with the POWER knob - do NOT vary the audio
> level.
>
> 73,
> Don W3FPR
>
> On 6/17/2019 9:38 AM, Conrad PA5Y wrote:
> >
> > Historically there were all kinds of low level artefacts produced by
> Windows audio algorithms, including the volume control. This was
> caused by insufficient precision leading to truncation artefacts. I
> have not tested it for a while and so it may no longer be the case.
> The result when I did test it was spectral smearing and some AM on
> what should be a constant envelope signal. I trust the power control
> in WSJT-X far more than that from the Windows mixer. These effects
> only really matter during weak signal conditions when your TX signal
> is on or near the noise floor. at the receiving station However they
> do make your signal wider.
> >
> > Also be careful how you vary power, reducing audio carelessly will
> invariably decrease the signal to noise on your TX signal which will
> also affect a stations ability to receive you.
> >
> > My K3S arrives this week and I will make some tests to see exactly
> what happens with TX composite noise when power is reduced with the
> power control and by reducing audio drive from the PC. Unless someone
> else has measured this already?
> >

k4vd

Re: Next Question: DATA A with K3s and Fldigi

Hi Conrad:

I'm looking forward to your tests. I have things set up per Don's and Bob's
suggestions at the moment.

Windows level: -14.7db
fldigi level: -15.7 db
K3s level: 31

Again, I have not way to test quantitatively but the couple of comments
seems to indicate things are fine. I have this old KK7UQ IMD Meter which I
used to trust but it seems it's not working well or I need a new battery in
it. It's reading around -19 db IMD while my old rigs were at -30 easy. I'm
not trusting the meter at the moment.

Kev

On Mon, Jun 17, 2019 at 11:50 AM Conrad PA5Y <[hidden email]> wrote:

> Don, it depends on the hardware. I would be very surprised if the Audio
> codec used in the K3S can reach full scale with the windows mixer at max. I
> expect that it is limited to -1dB FS. Also I believe that there are further
> limits imposed i WSJT-X. Therefore there should be no reason for clipping
> to occur in the CODEC. I expect that there is sufficient range in the mic
> gain (or whatever it is called) on the K3S. This gives the input signal the
> maximum SNR which is the socially responsible thing to do.
>
> Until I have checked the behaviour of the windows mixer with the CODEC I
> will not be using it. As I have said previously I don't trust the windows
> mixer not to degrade the audio due This may well have been resolved but
> historically was of concern.
>
> I think that I will decide what to do when I have made some proper
> measurements. It's not that I don't believe you, I just like to check
> things for myself.
>
> 73
>
> Conrad PA5Y
>
>
> ________________________________
> From: Don Wilhelm <[hidden email]>
> Sent: 17 June 2019 17:31
> To: Conrad PA5Y; [hidden email]
> Subject: Re: [Elecraft] Next Question: DATA A with K3s and Fldigi
>
> Conrad,
>
> Do check and adjust the Windows soundcard controls to mid-range. When
> set to extremes, it can cause clipping and distortion.
>
> With the K3S, the internal soundcard will identify as USB AUDIO CODEC.
>
> 73,
> Don W3FPR
>
> On 6/17/2019 11:21 AM, Conrad PA5Y wrote:
> > Don of course it is not a power control, that is obvious to me.
> >
> > I am very fortunate to have a lot of RF and Audio test equipment
> > available both at home and at work so I will measure what works best
> > and try to understand why. I will be happy to share my findings. I
> > will of course read your article. I am loathe to use the Windows audio
> > mixer, I would rather use an external passive attenuator. Maybe the
> > Windows mixer has improved, I need to check that with an audio
> > analyser. It used to be awful so I built an external passive
> > attenuator some years ago.
> >
> > I will be interested to see what happens to the K3S TX composite noise
> > when the power control is used. There is a certain very popular radio
> > where the AM noise comes up by 20 dB when the power is reduced from
> > 100W to 30W. I would be really pleased if the K3S power control works
> > properly!
> >
> > I bought the K3S purely for its TX PN performance.
> >
> > 73
> >
> > Conrad PA5Y
> > ------------------------------------------------------------------------
> > *From:* Don Wilhelm <[hidden email]>
> > *Sent:* 17 June 2019 16:03:02
> > *To:* Conrad PA5Y; [hidden email]
> > *Subject:* Re: [Elecraft] Next Question: DATA A with K3s and Fldigi
> > Conrad and all,
> >
> > The POWER control in WSJT-X is a misnomer. It is actually an audio
> > level control. Do NOT use it to control the power with an Elecraft
> > transceiver - set the audio correctly and use the power knob to control
> > the power.
> >
> > While other amateur transceivers can be made to control the power by
> > varying the audio level, that can be disastrous for Elecraft transceiver
> > Power Control. Read the relevant article on my website www.w3fpr.com<
> http://www.w3fpr.com>
> > <http://www.w3fpr.com>
> > for a full explanation.
> >
> > Set the WSJT-X POWER control for 30% to 50% and do the same for the
> > soundcard control in Windows Mixer, then set the LINE IN gain in the
> > K3/S to somewhere near mid-range. By manipulation of those 3 audio
> > level controls, you should be able to achieve the 'magic' indication of
> > 4 bars solid on the ALC meter with the 5th bar flashing - that is the
> > "NO ALC" point for the K3/S, KX3, and KX2 transeivers. The lower 4 bars
> > of the "ALC" meter are there as an aid for setting the audio levels.
> > Set the desired power output with the POWER knob - do NOT vary the audio
> > level.
> >
> > 73,
> > Don W3FPR
> >
> > On 6/17/2019 9:38 AM, Conrad PA5Y wrote:
> > >
> > > Historically there were all kinds of low level artefacts produced by
> > Windows audio algorithms, including the volume control. This was
> > caused by insufficient precision leading to truncation artefacts. I
> > have not tested it for a while and so it may no longer be the case.
> > The result when I did test it was spectral smearing and some AM on
> > what should be a constant envelope signal. I trust the power control
> > in WSJT-X far more than that from the Windows mixer. These effects
> > only really matter during weak signal conditions when your TX signal
> > is on or near the noise floor. at the receiving station However they
> > do make your signal wider.
> > >
> > > Also be careful how you vary power, reducing audio carelessly will
> > invariably decrease the signal to noise on your TX signal which will
> > also affect a stations ability to receive you.
> > >
> > > My K3S arrives this week and I will make some tests to see exactly
> > what happens with TX composite noise when power is reduced with the
> > power control and by reducing audio drive from the PC. Unless someone
> > else has measured this already?
> > >
>
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