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Elecraft KX3 IQ out and spectral display pograms

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Chris Tate - N6WM

Elecraft KX3 IQ out and spectral display pograms

Greetings and happy holidays Elecraft enthusiasts.

I have been putting together a portable contest/dx station using a KX3/KXPA100 combo. What a wonderful little setup. As part of my testing process, I have setup a laptop computer for rig control. This works great in alot of respects, Cat control.. no problem. Keying cw from the computer.. no problem. I have run into a tiny issue, regarding the IQ out and how it integrates with computer based spectral display applications and I am hoping the fine brain trust of audio experts can help me out.

I have a creative EM 0204, and I have split out the IQ stereo into 2 channels using a 1/8 stereo to mono a/b splitter, and subsequently feed IQ to the EM 0204 into the L/R mono ports. I am having some issues that I have not run into.. for instance when I used to do this using an N8LP pan with my K3. (I have done sufficient testing with other computers, sound cards to be aware this is not limited to just this equipment). here is what my observations are:

CW Skimmer. Seems to work.. but the IQ balance seems to fall out of sync after being dialed in. in other words from time to time multiple traces of signals appear. this after adjusting with a fixed carrier on WWV to remove the traces. Its almost as if there is an IQ instability of some kind and I was curious what others have found.

PAN displays, NAP3, etc.: there seems to be a rather large artifact that tracks with the center frequency making use of the pan display rather impractical...maybe 20-30 Kc's or more. I assume this issue is resolved to make the PX3 display an accurate spectral representation, and so am wondering if there must be a setting or something I have adjusted incorrectly.

I also ran into an audio artifact where I could hear computer rfi through the headphones with the IQ cable plugged in.. I was able to mitigate this using a ground loop isolation cable.. keeping in mind I want to keep this setup portable and useable in remote locations.

IF anyone who may have resolved some of these IQ out issues could chime in and assist it would be greatly appreciated. I am trying to make this setup as capable and portable as possible.

thanks in advance and look forward to your responses.

Chris
N6WM

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Barry K3NDM

Re: Elecraft KX3 IQ out and spectral display pograms

Chris.
I have switched over to Win4K3. It's a total package with spectrum
display, IP connection to HRD, works well with CWskimmer, and now there
is spotting and a log program, albeit the logging function is still
being worked on. It seems to run much more smoothly than NaP3 with LP
Bridge.

From reading your post I suggest that you get a Radio Shack ground
loop isolator. It seemed to fix a number of things in my set up and they
are inexpensive. One my overcome some, if not all, your issues.

73,
Barry
K3NDM

On 12/20/2014 2:13 PM, Chris Tate - N6WM wrote:

> Greetings and happy holidays Elecraft enthusiasts.
>
> I have been putting together a portable contest/dx station using a KX3/KXPA100 combo. What a wonderful little setup. As part of my testing process, I have setup a laptop computer for rig control. This works great in alot of respects, Cat control.. no problem. Keying cw from the computer.. no problem. I have run into a tiny issue, regarding the IQ out and how it integrates with computer based spectral display applications and I am hoping the fine brain trust of audio experts can help me out.
>
>
> I have a creative EM 0204, and I have split out the IQ stereo into 2 channels using a 1/8 stereo to mono a/b splitter, and subsequently feed IQ to the EM 0204 into the L/R mono ports. I am having some issues that I have not run into.. for instance when I used to do this using an N8LP pan with my K3. (I have done sufficient testing with other computers, sound cards to be aware this is not limited to just this equipment). here is what my observations are:
>
> CW Skimmer. Seems to work.. but the IQ balance seems to fall out of sync after being dialed in. in other words from time to time multiple traces of signals appear. this after adjusting with a fixed carrier on WWV to remove the traces. Its almost as if there is an IQ instability of some kind and I was curious what others have found.
>
> PAN displays, NAP3, etc.: there seems to be a rather large artifact that tracks with the center frequency making use of the pan display rather impractical...maybe 20-30 Kc's or more. I assume this issue is resolved to make the PX3 display an accurate spectral representation, and so am wondering if there must be a setting or something I have adjusted incorrectly.
>
> I also ran into an audio artifact where I could hear computer rfi through the headphones with the IQ cable plugged in.. I was able to mitigate this using a ground loop isolation cable.. keeping in mind I want to keep this setup portable and useable in remote locations.
>
> IF anyone who may have resolved some of these IQ out issues could chime in and assist it would be greatly appreciated. I am trying to make this setup as capable and portable as possible.
>
> thanks in advance and look forward to your responses.
>
> Chris
> N6WM
>
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>

Chris Tate - N6WM

Re: Elecraft KX3 IQ out and spectral display pograms

In reply to this post by Chris Tate - N6WM

Oh I forgot to mention that it would also be great to hear from folks who have gotten this working correctly, and if so what were your settings and equipment.

Thanks

~C./WM
________________________________________
From: Elecraft [[hidden email]] on behalf of Chris Tate - N6WM [[hidden email]]
Sent: Saturday, December 20, 2014 11:13 AM
To: [hidden email]
Subject: [Elecraft] Elecraft KX3 IQ out and spectral display pograms

Greetings and happy holidays Elecraft enthusiasts.

I have been putting together a portable contest/dx station using a KX3/KXPA100 combo. What a wonderful little setup. As part of my testing process, I have setup a laptop computer for rig control. This works great in alot of respects, Cat control.. no problem. Keying cw from the computer.. no problem. I have run into a tiny issue, regarding the IQ out and how it integrates with computer based spectral display applications and I am hoping the fine brain trust of audio experts can help me out.

I have a creative EM 0204, and I have split out the IQ stereo into 2 channels using a 1/8 stereo to mono a/b splitter, and subsequently feed IQ to the EM 0204 into the L/R mono ports. I am having some issues that I have not run into.. for instance when I used to do this using an N8LP pan with my K3. (I have done sufficient testing with other computers, sound cards to be aware this is not limited to just this equipment). here is what my observations are:

CW Skimmer. Seems to work.. but the IQ balance seems to fall out of sync after being dialed in. in other words from time to time multiple traces of signals appear. this after adjusting with a fixed carrier on WWV to remove the traces. Its almost as if there is an IQ instability of some kind and I was curious what others have found.

PAN displays, NAP3, etc.: there seems to be a rather large artifact that tracks with the center frequency making use of the pan display rather impractical...maybe 20-30 Kc's or more. I assume this issue is resolved to make the PX3 display an accurate spectral representation, and so am wondering if there must be a setting or something I have adjusted incorrectly.

I also ran into an audio artifact where I could hear computer rfi through the headphones with the IQ cable plugged in.. I was able to mitigate this using a ground loop isolation cable.. keeping in mind I want to keep this setup portable and useable in remote locations.

IF anyone who may have resolved some of these IQ out issues could chime in and assist it would be greatly appreciated. I am trying to make this setup as capable and portable as possible.

thanks in advance and look forward to your responses.

Chris
N6WM

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Chris Tate - N6WM

Re: Elecraft KX3 IQ out and spectral display pograms

In reply to this post by Barry K3NDM

Thanks Barry.. I am not having rig control issues and thus dont need to use LP-bridge at this time.

This seems specific to the IQ audio coming out of the IQ out of the KX3. I have experienced this on 2 KX3's and multiple sound card/computer combinations so I suspect an internal setting or something I have not found documented or missed. Since the PX3 is in existence.. there must be some setting/combo that fixes the spectral display as it is fed to a high end sound card.

and again I did not have this issue with the N8LP pan or the IF out of my K3's. This is specific to the IQ out feature of the K X 3.

If you read further you will find I did solve some of the computer RFI with a GLI.. in particular from radio shack. This seems to be required hardware at this point and needs to be put in line with the IQ out cable provided by elecraft. With it in line it is no longer a problem.

Thanks for the tip on Win4k3 Ill give that one a shot.

~C./WM
________________________________________
From: Elecraft [[hidden email]] on behalf of Barry LaZar [[hidden email]]
Sent: Saturday, December 20, 2014 12:42 PM
To: [hidden email]
Subject: Re: [Elecraft] Elecraft KX3 IQ out and spectral display pograms

Chris.
I have switched over to Win4K3. It's a total package with spectrum
display, IP connection to HRD, works well with CWskimmer, and now there
is spotting and a log program, albeit the logging function is still
being worked on. It seems to run much more smoothly than NaP3 with LP
Bridge.

From reading your post I suggest that you get a Radio Shack ground
loop isolator. It seemed to fix a number of things in my set up and they
are inexpensive. One my overcome some, if not all, your issues.

73,
Barry
K3NDM

On 12/20/2014 2:13 PM, Chris Tate - N6WM wrote:

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wb4jfi

Re: Elecraft KX3 IQ out and spectral display pograms

In reply to this post by Chris Tate - N6WM

I would check the splitter cable, or use another one. I have had numerous
times when the audio cable was not up to snuff (in different ways), and the
results are I/Q imbalance issues. I've even had Y adaptors from Radio Shack
that were completely miswired. You would think that simple cables could be
relied upon, but I've seen otherwise.
Good luck.
73, Terry, WB4JFI

-----Original Message-----
From: Chris Tate - N6WM
Sent: Saturday, December 20, 2014 2:13 PM
To: [hidden email]
Subject: [Elecraft] Elecraft KX3 IQ out and spectral display pograms

Greetings and happy holidays Elecraft enthusiasts.

I have been putting together a portable contest/dx station using a
KX3/KXPA100 combo. What a wonderful little setup. As part of my testing
process, I have setup a laptop computer for rig control. This works great
in alot of respects, Cat control.. no problem. Keying cw from the
computer.. no problem. I have run into a tiny issue, regarding the IQ out
and how it integrates with computer based spectral display applications and
I am hoping the fine brain trust of audio experts can help me out.

I have a creative EM 0204, and I have split out the IQ stereo into 2
channels using a 1/8 stereo to mono a/b splitter, and subsequently feed IQ
to the EM 0204 into the L/R mono ports. I am having some issues that I have
not run into.. for instance when I used to do this using an N8LP pan with my
K3. (I have done sufficient testing with other computers, sound cards to be
aware this is not limited to just this equipment). here is what my
observations are:

CW Skimmer. Seems to work.. but the IQ balance seems to fall out of sync
after being dialed in. in other words from time to time multiple traces of
signals appear. this after adjusting with a fixed carrier on WWV to remove
the traces. Its almost as if there is an IQ instability of some kind and I
was curious what others have found.

PAN displays, NAP3, etc.: there seems to be a rather large artifact that
tracks with the center frequency making use of the pan display rather
impractical...maybe 20-30 Kc's or more. I assume this issue is resolved
to make the PX3 display an accurate spectral representation, and so am
wondering if there must be a setting or something I have adjusted
incorrectly.

I also ran into an audio artifact where I could hear computer rfi through
the headphones with the IQ cable plugged in.. I was able to mitigate this
using a ground loop isolation cable.. keeping in mind I want to keep this
setup portable and useable in remote locations.

IF anyone who may have resolved some of these IQ out issues could chime in
and assist it would be greatly appreciated. I am trying to make this setup
as capable and portable as possible.

thanks in advance and look forward to your responses.

Chris
N6WM

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tomb18

Re: Elecraft KX3 IQ out and spectral display pograms

In reply to this post by Chris Tate - N6WM

Hi
I have worked with someone who had a similar issue. In his case the iq signals were randomly swapping and that of course can ruin any balance that has been set. I have read recently of others on the kx3 yahoo group which report the same thing.
Extensive troubleshooting was done. It was not the software package in use. It did this with all.
In the case where I helped out the only thing that solved it was using a different computer. The problem never returned. We did determine though that high processor usage eliminated the problem. That's right, go figure.
It's a mystery.
Tom

On Dec 20, 2014 3:52 PM, Chris Tate - N6WM <[hidden email]> wrote:

>
> Thanks Barry.. I am not having rig control issues and thus dont need to use LP-bridge at this time.
>
> This seems specific to the IQ audio coming out of the IQ out of the KX3. I have experienced this on 2 KX3's and multiple sound card/computer combinations so I suspect an internal setting or something I have not found documented or missed.   Since the PX3 is in existence.. there must be some setting/combo that fixes the spectral display as it is fed to a high end sound card.
>
> and again I did not have this issue with the N8LP pan or the IF out of my K3's. This is specific to the IQ out feature of the K X 3.
>
> If you read further you will find I did solve some of the computer RFI with a GLI.. in particular from radio shack. This seems to be required hardware at this point and needs to be put in line with the IQ out cable provided by elecraft. With it in line it is no longer a problem.
>
> Thanks for the tip on Win4k3 Ill give that one a shot.
>
> ~C./WM
> ________________________________________
> From: Elecraft [[hidden email]] on behalf of Barry LaZar [[hidden email]]
> Sent: Saturday, December 20, 2014 12:42 PM
> To: [hidden email]
> Subject: Re: [Elecraft] Elecraft KX3 IQ out and spectral display pograms
>
> Chris.
>      I have switched over to Win4K3. It's a total package with spectrum
> display, IP connection to HRD, works well with CWskimmer, and now there
> is spotting and a log program, albeit the logging function is still
> being worked on. It seems to run much more smoothly than NaP3 with LP
> Bridge.
>
>      From reading your post I suggest that you get a Radio Shack ground
> loop isolator. It seemed to fix a number of things in my set up and they
> are inexpensive. One my overcome some, if not all, your issues.
>
> 73,
> Barry
> K3NDM
>
> On 12/20/2014 2:13 PM, Chris Tate - N6WM wrote:
> > Greetings and happy holidays Elecraft enthusiasts.
> >
> > I have been putting together a portable contest/dx station using a KX3/KXPA100 combo. What a wonderful little setup. As part of my testing process, I have setup a laptop computer for rig control. This works great in alot of respects, Cat control.. no problem. Keying cw from the computer.. no problem. I have run into a tiny issue, regarding the IQ out and how it integrates with computer based spectral display applications and I am hoping the fine brain trust of audio experts can help me out.
> >
> >
> > I have a creative EM 0204, and I have split out the IQ stereo into 2 channels using a 1/8 stereo to mono a/b splitter, and subsequently feed IQ to the EM 0204 into the L/R mono ports. I am having some issues that I have not run into.. for instance when I used to do this using an N8LP pan with my K3. (I have done sufficient testing with other computers, sound cards to be aware this is not limited to just this equipment). here is what my observations are:
> >
> > CW Skimmer. Seems to work.. but the IQ balance seems to fall out of sync after being dialed in. in other words from time to time multiple traces of signals appear. this after adjusting with a fixed carrier on WWV to remove the traces. Its almost as if there is an IQ instability of some kind and I was curious what others have found.
> >
> > PAN displays, NAP3, etc.: there seems to be a rather large artifact that tracks with the center frequency making use of the pan display rather impractical...maybe 20-30 Kc's or more.    I assume this issue is resolved to make the PX3 display an accurate spectral representation, and so am wondering if there must be a setting or something I have adjusted incorrectly.
> >
> > I also ran into an audio artifact where I could hear computer rfi through the headphones with the IQ cable plugged in..   I was able to mitigate this using a ground loop isolation cable.. keeping in mind I want to keep this setup portable and useable in remote locations.
> >
> > IF anyone who may have resolved some of these IQ out issues could chime in and assist it would be greatly appreciated. I am trying to make this setup as capable and portable as possible.
> >
> > thanks in advance and look forward to your responses.
> >
> > Chris
> > N6WM
> >
> >
> >
> > ______________________________________________________________
> > 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]
> >
>
> ______________________________________________________________
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> Message delivered to [hidden email]
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Jim Brown-10

Re: Elecraft KX3 IQ out and spectral display pograms

In reply to this post by Barry K3NDM

On Sat,12/20/2014 12:42 PM, Barry LaZar wrote:
> From reading your post I suggest that you get a Radio Shack ground
> loop isolator.

A far better suggestion for both of you. Download and study this
tutorial. Anyone who uses or suggests a "ground loop isolator" has some
severe misunderstandings of the fundamentals of electrical circuits.

http://k9yc.com/GroundingAndAudio.pdf

73, Jim K9YC
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Alan Bloom

Re: Elecraft KX3 IQ out and spectral display pograms

In reply to this post by Chris Tate - N6WM

Perhaps the problem is due to noise on the computer ground. The PX3 has
differential amplifiers at the I/Q inputs. For the computer-based
panadapter, it might help to connect the grounds of the computer audio
input connectors to the KX3 ground with a short, large-diameter wire.

Another possible solution would be to use audio isolation transformers
on the I and Q signals to isolate the grounds. That will cause a notch
in the panadapter response. The notch width will be twice the
transformers' low-frequency cutoff frequency.

Alan N1AL

On 12/20/2014 11:13 AM, Chris Tate - N6WM wrote:

Jim Brown-10

Re: Elecraft KX3 IQ out and spectral display pograms

On Sat,12/20/2014 4:57 PM, Alan wrote:
> Perhaps the problem is due to noise on the computer ground. The PX3
> has differential amplifiers at the I/Q inputs.

Why? It's an unbalanced interface!

> For the computer-based panadapter, it might help to connect the
> grounds of the computer audio input connectors to the KX3 ground with
> a short, large-diameter wire.

PLEASE study my tutorial on Bonding, previously linked. What should be
bonded are the CHASSIS of all the interconnected equipment.

>
> Another possible solution would be to use audio isolation transformers
> on the I and Q signals to isolate the grounds. That will cause a
> notch in the panadapter response. The notch width will be twice the
> transformers' low-frequency cutoff frequency.

This is smelling VERY much like Pin One Problems. The KX3 has Pin One
Problems at the connectors not screwed down to the chassis. The only
connectors screwed down to the chassis are mic connector and the BNC
antenna connector. On the PX3, two of the I/O connectors are not screwed
down to the chassis. THESE ARE PIN ONE PROBLEMS.

The ONLY proper connection point for a cable shield the is shielding
enclosure. When a cable shield is insulated from the shielding enclosure
and goes through an enclosure penetration to the circuit board, that
cable, and that equipment are UNSHIELDED, and the cable shield conducts
shield current into the equipment.

PLEASE study my material on The Pin One Problem. Many users would be
spared a lot of grief if gear was built without Pin One Problems.

k9yc.com/publish.htm

And please excuse my frustration about this. Thanks to the late Neil
Muncy, W3WJE, we discovered and fixed our Pin One Problems in the pro
audio world back in 1994. Ham gear is full of Pin One Problems, and I've
been trying to teach ham manufacturers about this issue for ten years. I
first discussed this with Wayne in Dayton in 2004 or 2005. It's almost
2015, and Elecraft products are still being built with Pin One Problems.

73, Jim K9YC

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Jim Wiley

K2 plus options on eBay now

For anyone interested, I have listed my K2 on eBay. It has all options
except for 60 meters, and several additional items such as a Palm
Paddle, MC-43 hand microphone, Samsonite carry bag, Nifty operating
guide, and much more.

The "buy it now" price includes free shipping to all US states and
territories.

The item number is 221641058241

- Jim, KL7CC

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Alan Bloom

Re: Elecraft KX3 IQ out and spectral display pograms

In reply to this post by Jim Brown-10

> Why? It's an unbalanced interface!

Yes, that's the problem. The power supply in the computer probably has
bypass/filter capacitors between the line and the chassis. So with an
unbalanced connection to the KX3, there will be 60 Hz (and harmonics) AC
current flowing in the cable shields. Even a fraction of a millivolt
voltage drop in the shield is enough to cause a visible 60 Hz spur on
the panadapter display.

The voltage drop can be reduced by connecting a short, low-resistance
wire between the two chassis. I suggested making the connection on the
computer end to the audio connector shells to make sure you're
connecting to the ground reference of the sound card, which might be
different from other points on the chassis. That may have been bad
advice - I'm not an expert on the construction of a typical PC chassis.

But I think isolation transformers would be an even better solution.
That should completely eliminate hum caused by different voltages on the
two chassis.

The PX3 uses differential sensing on the I/Q inputs instead of isolation
transformers. In effect, the PX3 ground reference is the KX3 chassis,
rather than the PX3 chassis. That way, even if there is a 60 Hz voltage
difference between the two chassis, it won't cause interference.

> This is smelling VERY much like Pin One Problems.

For those who aren't familiar with the term, the so-called "pin one"
problem is when the ground pin on a connector is not connected directly
to the chassis but rather via a wire, PC board, etc. I believe the name
comes from audio XLR connectors, which use pin 1 as the ground.

The pin one problem normally shows up at RF frequencies because of the
inductance of the internal ground connection. But the issue under
discussion is 60 Hz interference, so I doubt that that's the problem.

Alan N1AL

On 12/20/2014 07:36 PM, Jim Brown wrote:

> On Sat,12/20/2014 4:57 PM, Alan wrote:
>> Perhaps the problem is due to noise on the computer ground. The PX3
>> has differential amplifiers at the I/Q inputs.
>
> Why? It's an unbalanced interface!
>
>> For the computer-based panadapter, it might help to connect the
>> grounds of the computer audio input connectors to the KX3 ground with
>> a short, large-diameter wire.
>
> PLEASE study my tutorial on Bonding, previously linked. What should
> be bonded are the CHASSIS of all the interconnected equipment.
>
>>
>> Another possible solution would be to use audio isolation
>> transformers on the I and Q signals to isolate the grounds. That will
>> cause a notch in the panadapter response. The notch width will be
>> twice the transformers' low-frequency cutoff frequency.
>
> This is smelling VERY much like Pin One Problems. The KX3 has Pin One
> Problems at the connectors not screwed down to the chassis. The only
> connectors screwed down to the chassis are mic connector and the BNC
> antenna connector. On the PX3, two of the I/O connectors are not
> screwed down to the chassis. THESE ARE PIN ONE PROBLEMS.
>
> The ONLY proper connection point for a cable shield the is shielding
> enclosure. When a cable shield is insulated from the shielding
> enclosure and goes through an enclosure penetration to the circuit
> board, that cable, and that equipment are UNSHIELDED, and the cable
> shield conducts shield current into the equipment.
>
> PLEASE study my material on The Pin One Problem. Many users would be
> spared a lot of grief if gear was built without Pin One Problems.
>
> k9yc.com/publish.htm
>
> And please excuse my frustration about this. Thanks to the late Neil
> Muncy, W3WJE, we discovered and fixed our Pin One Problems in the pro
> audio world back in 1994. Ham gear is full of Pin One Problems, and
> I've been trying to teach ham manufacturers about this issue for ten
> years. I first discussed this with Wayne in Dayton in 2004 or 2005.
> It's almost 2015, and Elecraft products are still being built with Pin
> One Problems.
>
> 73, Jim K9YC
>
>
>
>
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Jim Brown-10

Re: Elecraft KX3 IQ out and spectral display pograms

On Sat,12/20/2014 11:13 PM, Alan wrote:
> The pin one problem normally shows up at RF frequencies because of the
> inductance of the internal ground connection. But the issue under
> discussion is 60 Hz interference, so I doubt that that's the problem.

Again, PLEASE study the tutorial.

73, Jim
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Edward R Cole

Re: Elecraft KX3 IQ out and spectral display pograms

In reply to this post by Chris Tate - N6WM

When I first got my LP-Pan and read the manual (doesn't everyone do
this?), I found it strange that the audio outputs had the ability to
lift grounds (apparently to reduce noise/ground-loop issues). I
guess I must be doing something right as I did not encounter any hum
or noise issues with audio shields grounded.

In the early years of building radio-computer I/F boxes (HB) it
became quickly evident that isolation transformers solved a lot of
these "grounding issues".

I read your presentation, Jim, and gives me a laundry list of things to check.

73, Ed - KL7UW
http://www.kl7uw.com
"Kits made by KL7UW"
Dubus Mag business:
[hidden email]

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Phil Wheeler-2

Re: Elecraft KX3 IQ out and spectral display pograms

I've used my KX3 with the Tiny Python Panadapter I
built per the April QST, using an iMic USB audio
card on the I/Q outputs, and it worked fine --
within the limits of the design and the Raspberry
Pi I used. Nowhere near as nice as the PX3 I'm
using now when I operate the KX3:-)

73, Phil W7OX

On 12/21/14 5:41 PM, Edward R Cole wrote:

> When I first got my LP-Pan and read the manual
> (doesn't everyone do this?), I found it strange
> that the audio outputs had the ability to lift
> grounds (apparently to reduce noise/ground-loop
> issues). I guess I must be doing something
> right as I did not encounter any hum or noise
> issues with audio shields grounded.
>
> In the early years of building radio-computer
> I/F boxes (HB) it became quickly evident that
> isolation transformers solved a lot of these
> "grounding issues".
>
> I read your presentation, Jim, and gives me a
> laundry list of things to check.
>
> 73, Ed - KL7UW
> http://www.kl7uw.com
> "Kits made by KL7UW"
> Dubus Mag business:
> [hidden email]

Chris Tate - N6WM

Re: Elecraft KX3 IQ out and spectral display pograms

In reply to this post by Jim Brown-10

Ok. This issue has been resolved.

First I want to send a huge Thanks to K9YC for his body of work on RFI, and bonding , as well as W3FPR for setting me straight where I should be reading on the pan adapter and soundcard isses. I spent some quality time, along with an offline email (thanks Jim) and ended up bonding all equipment, laptop, KX3, basically any chassis. Since this is an expedition kit, I took his advice and built pigtails with power pole connectors connected to each chassis in the setup. This allows quick assembly and breakdown of the bonding system. After doing this First result.. all audible rfi noise in headphones.. gone. Voltage between devices seems to have been balanced. Spot on Jim. This was great, and it gets better.

The noise I was seeing on waterfalls seems to be nastiness coming from the USB system on the laptop. I did some snooping with an HT to narrow this down. I applied a ferrite choke onto the USB cable along with ensuring a very secure connection to the USB port.. fired up the system and bingo.. 98% of the displayed noise on the waterfall is gone. (I am not sure if the Choke worked or if it was a loose connection, or both).

Lessons learned..
1. Read the Elecraft Manual. Carefully.
2. Read K9YC presentation and data Carefully. Raise your hands and say.. "You are the go to man for this Reverend Jim!"
3. Read telepost soundcard page. Read it again. Thanks again Don.. They have really added a lot of info since the last time I looked there.
4. Reach out to the authors as needed to reassure yourself what you read is true :-). (I guess it's a ham thing.. or maybe an N6WM thing hi hi)

Net result (with all these little challenges solved) is I have the best sounding fully functional compact expedition/portable contestpedition setup that can fit in a pelican case(in my opinion.)

Consists of KX3/KXPA100 Thinkpad notebook, mini speakers, small power supply, Xonar sound card, footswitch(tested and working) , headphones(CM500 tx audio dialed in), budipole and battery for the really remote stuff. With the IQ out into the Xonar , I have skimmer, N1MM Plus, and even power SDR running in a stable state giving a full waterfall display of my choosing. In fact I have them running all simultaneously. The entire setup works, and works well.

Now I can pack all this stuff up and get back to planning its first travel date, and using my K3/0 connected to my "not on expedition" K-line at the hilltop station.

Thanks K9YC and everyone else who responded.. this was a fun project... and of course keep cranking out these super cool products Eric and Wayne!

~Chris
N6WM

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VE3NFK

Re: Elecraft KX3 IQ out and spectral display pograms

In reply to this post by Jim Brown-10

Hi Jim

Thanks for the information - possibly you might suggest what the end user might do to fix the KX3 pin 1 problems on the other connectors?

thanks and Merry Christmas

73 John VE3NFK

Jim Brown-10

Re: Elecraft KX3 IQ out and spectral display pograms

On Wed,12/24/2014 2:46 PM, VE3NFK wrote:
> Hi Jim
>
> Thanks for the information - possibly you might suggest what the end user
> might do to fix the KX3 pin 1 problems on the other connectors?

There's probably not an easy way to fix it -- it's established by how
the radio is built, and changing would be major surgery. These are
things that Elecraft has to fix.

What we CAN do is "put band-aids" on the problem. Several basic measures.

1) Bond chassis-to-chassis of all interconnected equipment, bond from
that equipment to all grounds, and carefully bond all grounds together.

2) Place ferrite common mode chokes on cables plugged into connectors
with Pin One Problems, tuning the chokes to the frequencies where
interference is a concern. Follow guidelines in k9yc.com/RFI-Ham.pdf

3) Keep cables plugged into connectors with Pin One Problems as short as
practical.

73, Jim K9YC
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