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KX3 Question

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Jeff Herr

KX3 I/Q to soundcard isolation

I need to provide electrical isolation between the I/Q output and my
mic/line input.
Since this is a 2 channel output I need 2 channel (stereo) isolation.

Is there a commercial product anyone can point out to do this?

If not then I must choose a couple of audio transformers and wire them up to
do the job.
Would someone care to make a recommendation?

Here is the DigiKey audio transformer page for easy reference
http://www.digikey.com/product-search/en/transformers/audio/786564

Jeff Herr WW6L
4636 Kelton Way
Sacramento,CA 95838
916.925.6089
[hidden email]

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Barry K3NDM

Re: KX3 I/Q to soundcard isolation

Jeff,
I don't know what problem you're having, but I run without any
additional isolation with no problem. I go directly from my KX3 I&Q out
to my soundcard. Try it and see if you really need to go to the extra grief.

73,
Barry
K3NDM

On 10/14/2012 4:43 PM, Jeff Herr wrote:

> I need to provide electrical isolation between the I/Q output and my
> mic/line input.
> Since this is a 2 channel output I need 2 channel (stereo) isolation.
>
> Is there a commercial product anyone can point out to do this?
>
> If not then I must choose a couple of audio transformers and wire them up to
> do the job.
> Would someone care to make a recommendation?
>
> Here is the DigiKey audio transformer page for easy reference
> http://www.digikey.com/product-search/en/transformers/audio/786564
>
>
>
> Jeff Herr WW6L
> 4636 Kelton Way
> Sacramento,CA 95838
> 916.925.6089
> [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
>

Matt Zilmer

Re: KX3 I/Q to soundcard isolation

In reply to this post by Jeff Herr

If you're using a RigBlaster, you already have isolation. If not,
you'll need to buy or wire up a galvanic isolator.

73,
matt W6NIA
KX3 #6

On Sun, 14 Oct 2012 13:43:40 -0700, you wrote:

>I need to provide electrical isolation between the I/Q output and my
>mic/line input.
>Since this is a 2 channel output I need 2 channel (stereo) isolation.
>
>Is there a commercial product anyone can point out to do this?
>
>If not then I must choose a couple of audio transformers and wire them up to
>do the job.
>Would someone care to make a recommendation?
>
>Here is the DigiKey audio transformer page for easy reference
>http://www.digikey.com/product-search/en/transformers/audio/786564
>
>
>
>Jeff Herr WW6L
>4636 Kelton Way
>Sacramento,CA 95838
>916.925.6089
>[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

Don Wilhelm-4

Re: KX3 I/Q to soundcard isolation

In reply to this post by Jeff Herr

Jeff,

I have used transformers salvaged from computer modem cards and I have
used Xicon P/N 42TL016-R - Mouser PN 42TLC16-RC with success.

Yes, there is some falloff in the response if you try to use 192 kHz
display width, but then there is some falloff in the KX3 I/Q outputs for
that width anyway. 96 kHz is more practical with the KX3.

I mount my transformers in an Altiods tin and have a 3.5mm jack on each
end of the cables exiting the Altiods box. One end goes to the
soundcard and the other end goes to a 2.5 to 3.5 mm converter cable that
plugs into the KX3.

73,
Don W3FPR

On 10/14/2012 4:43 PM, Jeff Herr wrote:

Josh Lehan

Re: KX3 Question

In reply to this post by Matt Maguire

On 10/13/2012 08:32 PM, Matt Maguire wrote:
> On 14/10/2012, at 1:49 PM, Don Wilhelm <[hidden email]> wrote:
>
>> I recommend that all users do the refinement.
>
> With the new per-band alignment settings introduced in the latest firmware, this is probably not a bad idea.

Wow, per-band alignment?

Is this for the RX sideband gain/phase nullification? I did that when
connecting my KXFL3 (purchased separately, so required to do). However,
I only did it using the rather cool little white wire "antenna" loop
included by Elecraft with the KXFL3, which sniffs the 16MHz clock of the
board, using that as a signal source. If per-band alignment is now
possible to do, what are the recommendations for using other frequencies
besides 16MHz? This will be difficult for me, because I don't have a
signal generator that can create an artificial "known good" signal for
any other bands.

Thank you!

Josh
K6JSH (formerly KJ6PVN)

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Giampiero Raschetti

Re: KX3 I/Q to soundcard isolation

In reply to this post by Barry K3NDM

I do connect KX3 I&Q directly into my MacBookPro stereo in-line without any additional isolation too and it works great without any problem at all running under a parallels desktop virtual machine.
Is there any special reason to isolate this line ?

73, iw2esl / Giampiero

Sent from my iPad

On Oct 14, 2012, at 11:08 PM, Barry LaZar <[hidden email]> wrote:

> Jeff,
> I don't know what problem you're having, but I run without any
> additional isolation with no problem. I go directly from my KX3 I&Q out
> to my soundcard. Try it and see if you really need to go to the extra grief.
>
>
> 73,
> Barry
> K3NDM
>
> On 10/14/2012 4:43 PM, Jeff Herr wrote:
>> I need to provide electrical isolation between the I/Q output and my
>> mic/line input.
>> Since this is a 2 channel output I need 2 channel (stereo) isolation.
>>
>> Is there a commercial product anyone can point out to do this?
>>
>> If not then I must choose a couple of audio transformers and wire them up to
>> do the job.
>> Would someone care to make a recommendation?
>>
>> Here is the DigiKey audio transformer page for easy reference
>> http://www.digikey.com/product-search/en/transformers/audio/786564
>>
>>
>>
>> Jeff Herr WW6L
>> 4636 Kelton Way
>> Sacramento,CA 95838
>> 916.925.6089
>> [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
>
> ______________________________________________________________
> 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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Holger Schurig-2

Re: KX3 Question

In reply to this post by Josh Lehan

No, you can't do this with the "mini loop" antenna, you need a good &
strong signal source. Please read all the gory details at:

http://www.elecraft.com/manual/RX%20sideband%20null%20procedures%20rev%20A1.pdf

Works only with MCU 1.22 firmware.

73, DH3HS

P.S: Dear Elecraft webmaster: spaces in filenames suck! Thos %20 are
not pleasing the eye ... :-)
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Jeff Herr

Re: KX3 I/Q to soundcard isolation

In reply to this post by Giampiero Raschetti

When I connect to my asus laptop I get a flood of noise.....in the radio.

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Giampiero Raschetti
Sent: Sunday, October 14, 2012 22:02
To: Barry LaZar
Cc: [hidden email]
Subject: Re: [Elecraft] KX3 I/Q to soundcard isolation

I do connect KX3 I&Q directly into my MacBookPro stereo in-line without any
additional isolation too and it works great without any problem at all
running under a parallels desktop virtual machine.
Is there any special reason to isolate this line ?

73, iw2esl / Giampiero

Sent from my iPad

On Oct 14, 2012, at 11:08 PM, Barry LaZar <[hidden email]> wrote:

> Jeff,
> I don't know what problem you're having, but I run without any
> additional isolation with no problem. I go directly from my KX3 I&Q
> out to my soundcard. Try it and see if you really need to go to the extra
grief.

>
>
> 73,
> Barry
> K3NDM
>
> On 10/14/2012 4:43 PM, Jeff Herr wrote:
>> I need to provide electrical isolation between the I/Q output and my
>> mic/line input.
>> Since this is a 2 channel output I need 2 channel (stereo) isolation.
>>
>> Is there a commercial product anyone can point out to do this?
>>
>> If not then I must choose a couple of audio transformers and wire
>> them up to do the job.
>> Would someone care to make a recommendation?
>>
>> Here is the DigiKey audio transformer page for easy reference
>> http://www.digikey.com/product-search/en/transformers/audio/786564
>>
>>
>>
>> Jeff Herr WW6L
>> 4636 Kelton Way
>> Sacramento,CA 95838
>> 916.925.6089
>> [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
>
> ______________________________________________________________
> 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

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Giampiero Raschetti

Re: KX3 I/Q to soundcard isolation

Do you have this flood of noise in any laptop power condition or only when
operating while battery are charging and no noise when running with battery
power alone ?

On Mon, Oct 15, 2012 at 2:40 PM, Jeff Herr <[hidden email]> wrote:

> When I connect to my asus laptop I get a flood of noise.....in the radio.
>
> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Giampiero Raschetti
> Sent: Sunday, October 14, 2012 22:02
> To: Barry LaZar
> Cc: [hidden email]
> Subject: Re: [Elecraft] KX3 I/Q to soundcard isolation
>
> I do connect KX3 I&Q directly into my MacBookPro stereo in-line without
> any
> additional isolation too and it works great without any problem at all
> running under a parallels desktop virtual machine.
> Is there any special reason to isolate this line ?
>
> 73, iw2esl / Giampiero
>
>
> Sent from my iPad
>
> On Oct 14, 2012, at 11:08 PM, Barry LaZar <[hidden email]> wrote:
>
> > Jeff,
> > I don't know what problem you're having, but I run without any
> > additional isolation with no problem. I go directly from my KX3 I&Q
> > out to my soundcard. Try it and see if you really need to go to the extra
> grief.
> >
> >
> > 73,
> > Barry
> > K3NDM
> >
> > On 10/14/2012 4:43 PM, Jeff Herr wrote:
> >> I need to provide electrical isolation between the I/Q output and my
> >> mic/line input.
> >> Since this is a 2 channel output I need 2 channel (stereo) isolation.
> >>
> >> Is there a commercial product anyone can point out to do this?
> >>
> >> If not then I must choose a couple of audio transformers and wire
> >> them up to do the job.
> >> Would someone care to make a recommendation?
> >>
> >> Here is the DigiKey audio transformer page for easy reference
> >> http://www.digikey.com/product-search/en/transformers/audio/786564
> >>
> >>
> >>
> >> Jeff Herr WW6L
> >> 4636 Kelton Way
> >> Sacramento,CA 95838
> >> 916.925.6089
> >> [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
> >
> > ______________________________________________________________
> > 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
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>
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> Please help support this email list: http://www.qsl.net/donate.html
>
>

--
Giampiero Raschetti
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N6363LLL

Re: KX3 I/Q to soundcard isolation

Hello All,

There are big differences between interfacing a PC to the KX3 I/Q port compared to the needs of digital modes that use the headphone and mic audio connections. The I/Q port requires a flat bandpass to at least 48Khz. If you decide to use isolation transformers for the I/Q port, they must be very high quality and support wide bandwidth. If you use an external soundcard for the I/Q port, you must use a high quality soundcard that meets pro audio standards for noise, etc. See the data on the N8LP website about soundcards suitable for I/Q use. Your laptop might have a high quality stereo input soundcard and it's worth trying that first.

For the digital modes, a Rigblaster, Microham interface, US Navigator interface, RigExpert, SignalLink, etc. isolate monophonic low bandwidth audio going in both directions. They are not suitable for use on the I/Q port.

Steve Silverman KB3SII ... .. ..

Barry K3NDM

Re: KX3 I/Q to soundcard isolation

In reply to this post by Jeff Herr

Jeff et al,
I think I've been misreading things. I just sent you a note, but I
was thinking the problem was on the computer side. I just checked my
setup with no antenna input. There is a low level whine, but it
disappears when I connect up the antenna. I suspect I will detect it
again on 15 or 10 meters until I turn on the preamp.

My earlier comments were based on using the I&Q data with NaP3 and
using the computer's speakers for audio out. Except for some refresh
noise, which I noted in a private note to you, there is no noise problem.

At this point, I'm not sure what the lash up is. When using the
KX3's I&Q, I turn down/off the radio's audio and do EVERYTHING on my
laptop. I do use the line in to my laptop when I want to use the radio
as intended but want greater audio than is available from the radio's
speaker. What am I missing??

73,
Barry
K3NDM

On 10/15/2012 8:40 AM, Jeff Herr wrote:

> When I connect to my asus laptop I get a flood of noise.....in the radio.
>
> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Giampiero Raschetti
> Sent: Sunday, October 14, 2012 22:02
> To: Barry LaZar
> Cc: [hidden email]
> Subject: Re: [Elecraft] KX3 I/Q to soundcard isolation
>
> I do connect KX3 I&Q directly into my MacBookPro stereo in-line without any
> additional isolation too and it works great without any problem at all
> running under a parallels desktop virtual machine.
> Is there any special reason to isolate this line ?
>
> 73, iw2esl / Giampiero
>
>
> Sent from my iPad
>
> On Oct 14, 2012, at 11:08 PM, Barry LaZar <[hidden email]> wrote:
>
>> Jeff,
>> I don't know what problem you're having, but I run without any
>> additional isolation with no problem. I go directly from my KX3 I&Q
>> out to my soundcard. Try it and see if you really need to go to the extra
> grief.
>>
>> 73,
>> Barry
>> K3NDM
>>
>> On 10/14/2012 4:43 PM, Jeff Herr wrote:
>>> I need to provide electrical isolation between the I/Q output and my
>>> mic/line input.
>>> Since this is a 2 channel output I need 2 channel (stereo) isolation.
>>>
>>> Is there a commercial product anyone can point out to do this?
>>>
>>> If not then I must choose a couple of audio transformers and wire
>>> them up to do the job.
>>> Would someone care to make a recommendation?
>>>
>>> Here is the DigiKey audio transformer page for easy reference
>>> http://www.digikey.com/product-search/en/transformers/audio/786564
>>>
>>>
>>>
>>> Jeff Herr WW6L
>>> 4636 Kelton Way
>>> Sacramento,CA 95838
>>> 916.925.6089
>>> [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
>> ______________________________________________________________
>> 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
> ______________________________________________________________
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Jim Brown-10

Re: KX3 I/Q to soundcard isolation

In reply to this post by N6363LLL

On 10/15/2012 9:10 AM, N6363LLL wrote:
> There are big differences between interfacing a PC to the KX3 I/Q port
> compared to the needs of digital modes that use the headphone and mic audio
> connections. The I/Q port requires a flat bandpass to at least 48Khz.

The noise some are experiencing sounds like a Pin One Problem in the
computer, the rig, or both. Two cures, use both, but do #1 first,
because it's simpler and cheaper. NO TRANSFORMER IS REQUIRED.

1) Bond from the chassis of the computer/sound card to the chassis of
the rig with short fat copper. For more on this see
http://audiosystemsgroup.com/HamInterfacing.pdf

2) Use a serious multi-turn ferrite choke on the audio cable, using the
measured data in Appendix Oneof http://audiosystemsgroup.com/RFI-Ham.pdf
as a guide. Use Fair-Rite #31 or #43, depending the bands where you are
hearing noise. Put the choke on the audio cable(s), NOT on the bonding
wire.

3) Another important point. High futility cables often have lousy
shields (and often no shield at all, only a wire connecting the shield
contacts). I build my own audio cables using RG58 or RG174 and audio
connectors that I buy from Full Compass in Madison, WI. See the
above-cited references for part numbers.

73, Jim K9YC

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