[KX3] ADC/DAC access, keyer input

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Re: [KX3] ADC/DAC access, keyer input

Christian KJ4VPK
What we are talking about is moving the ADC in the PC sound card (or external USB sound card if you will) to the rig.  It would not encumber the DSP, the stages are the same as what it does today. Analog stereo could even exist for 1mm on the board trace.

What you are describing is far more complicated than that.

Trouble is today that 192 KHz USB sound cards are hard to come by (although the chipsets are widely available) and the same is true for a 192KHz sound card in the laptop/PC unless we are talking high end (=power hungry) hardware.

Oh well. Screams for an aftermarket gadget.

-----Original Message-----
From: Jessie Oberreuter
Sent: Friday, August 19, 2011 5:54 PM
To: Edward R. Cole
Cc: [hidden email]
Subject: Re: [Elecraft] [KX3] ADC/DAC access, keyer input


      Yes, the I/Q data is already in digital form inside the KX3, so -- in
theory -- it should be easy to just pump it to the outside world in
digital form.  The challenges are with the standards for that transfer.
      If you could accept real-time digital data at the same speed the DSP
is running at (say, via an optical port), this would be a no-brainer.
Were such a protocol common-place, Elecraft may well have used it.
      Unfortunately, it isn't.  USB, ethernet, S/PDIF, etc. all have some
sort of data framing, which means the KX3 would need to have additional
buffer and protocol circuitry to negotiate the link and then frame the
otherwise real-time I/Q data into packets that would then need to be
transfered at considerably higher than audio rates to prevent drop-outs.
      As a designer, you have three choices: you can create your own ad-hoc
lossless real-time digital protocol that almost no one will be able to
use, you can dramatically increase costs and complexity by implementing to
a more complex standard that many people still won't be able to use, or
you can take advantage of a commonly available protocol for transfering
real-time audio data that's perfectly adequate for the expected
applications: analog stereo.


On Fri, 19 Aug 2011, Edward R. Cole wrote:

> HUGE FAILURE TO COMMUNICATE, guys!!!
>
> The originator wanted a IF, shorthand for interface.  He should have
> written it I/F and then all this extraneous e-mail would have been avoided.
>
> The KX3, like the K3 is a SDR, meaning it has a IQ mixer to produce
> the quadrature data streams for the internal micro-processor to use
> for recovering modulation of multiple kinds of modes.  He is just
> wanting access at the digital level to the IQ data for use outside
> the radio.  This is what is not available in the K3 design.
>
> I understand the K3 was designed several years ago and wasn't
> intended to run anything but Elecraft's proprietory sw.  But times
> they do change - its 2011 and a whole lot is changing on the SDR
> scene if you really look.  What some of us are asking is for it to be
> able to run other sw outside the box.  It should not be that
> complicated to provide a digital port for exporting the IQ signal
> pair to an external computer.  No body wants more soundcards...the
> request is exactly to avoid them.
>
> The other wish for a keyboard port would be nice for a lot of us that
> might use the KX3 for CW and internally supported DATA modes (Psk,
> RTTY are a couple that come to mind).  I haven't read up on details
> that are out on the KX3, but now seems a good time to get any last
> minute design wishes expressed (for a radio going into production in 5-mo.).
> -----------------
> I am still on the fence on what direction I want to go regarding the
> KX3.  I have a FT-817 which was bought expressly for use as a 144-MHz
> IF for portable mw operations.  It also can operate on ham
> satellites, though not crossband duplex, which is desirable.  I may
> decide to sell off my FT-817 and some other stuff to raise cash for a
> KX3+2m transverter (embedded would be a nicety).  But I l already
> have a 144-28 transverter for using my SDR-IQ, which can be used with
> the KX3.  Only problem is it outputs 20mw for mw transverter I/F, so
> an upgrade would be needed for 5w.  I am assuming the KX3 will have a
> transverter I/F.
>
>
>
> 73, Ed - KL7UW, WD2XSH/45
> ======================================
> BP40IQ   500 KHz - 10-GHz   www.kl7uw.com
> EME: 50-1.1kw?, 144-1.4kw, 432-100w, 1296-60w, 3400-?
> DUBUS Magazine USA Rep [hidden email]
> ======================================
>
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Re: [KX3] ADC/DAC access, keyer input

k6dgw
In reply to this post by Jessie Oberreuter-2
One fundamental attraction of Elecraft gear [out of a countable infinity
of attractions, it seems] is its modularity ... you pay for what you
want.  You want an autotuner for your K2, you purchase the KAT2.  Don't
want it?  Don't buy it, and your K2 still works, it just wants to see
something close to 50 + j0 ohms at the SO-239.  Maybe you already have
another way to make that happen.

I-Q digital output signals are important to some.  Despite the fact that
I actually know what quadrature signals are and what you can do with
them, they are of zero interest to me and I really don't want to pay for
them, however they might be implemented.  I sincerely hope that the
almost extreme modularity that, among many other things, makes Elecraft
radios unique and highly desirable continues.  If digital I-Q signals
are a trivial cost, fine.  If not, I hope they are implemented in a
module and those for whom they're important can shoulder the cost.

73,

Fred Jensen
Auburn CA

On 8/19/2011 2:54 PM, Jessie Oberreuter wrote:
>
>        Yes, the I/Q data is already in digital form inside the KX3, so -- in
> theory -- it should be easy to just pump it to the outside world in
> digital form.  The challenges are with the standards for that transfer.
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Re: [KX3] ADC/DAC access, keyer input

wayne burdick
Administrator
Hi Fred,

The RX analog I/Q output jack adds very little to the cost. It's a standard feature.

Internal option modules include the ATU, roofing filter, and internal battery pack with real-time clock (RTC).

(Totally off-topic: The RTC can wake-up the radio at a programmed time, turning the KX3 into a high-performance clock radio :)

73,
Wayne
N6KR

----
http://www.elecraft.com

On Aug 19, 2011, at 5:13 PM, Fred Jensen <[hidden email]> wrote:

> One fundamental attraction of Elecraft gear [out of a countable infinity
> of attractions, it seems] is its modularity ... you pay for what you
> want.  You want an autotuner for your K2, you purchase the KAT2.  Don't
> want it?  Don't buy it, and your K2 still works, it just wants to see
> something close to 50 + j0 ohms at the SO-239.  Maybe you already have
> another way to make that happen.
>
> I-Q digital output signals are important to some.  Despite the fact that
> I actually know what quadrature signals are and what you can do with
> them, they are of zero interest to me and I really don't want to pay for
> them, however they might be implemented.  I sincerely hope that the
> almost extreme modularity that, among many other things, makes Elecraft
> radios unique and highly desirable continues.  If digital I-Q signals
> are a trivial cost, fine.  If not, I hope they are implemented in a
> module and those for whom they're important can shoulder the cost.
>
> 73,
>
> Fred Jensen
> Auburn CA
>
> On 8/19/2011 2:54 PM, Jessie Oberreuter wrote:
>>
>>       Yes, the I/Q data is already in digital form inside the KX3, so -- in
>> theory -- it should be easy to just pump it to the outside world in
>> digital form.  The challenges are with the standards for that transfer.
> ______________________________________________________________
> 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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Re: [KX3] ADC/DAC access, keyer input

Jessie Oberreuter-2
In reply to this post by Christian KJ4VPK

On Fri, 19 Aug 2011, Christian KJ4VPK wrote:
>
> Trouble is today that 192 KHz USB sound cards are hard to come by
> (although the chipsets are widely available) and the same is true for a
> 192KHz sound card in the laptop/PC unless we are talking high end
> (=power hungry) hardware. Oh well. Screams for an aftermarket gadget.

      I would normally think that competing in the USB dongle market would
be folly, but if there really is a gaping hole here, perhaps Elecraft
could fill it -- especially since they've recently waded into the
production side of such toys :).
      I do appreciate the need: I recently watched Ki7el, who is an IT
professional by day, struggle to find a USB soundcard for his recently
completed Ensemble transciever that offered stereo bit-rates compatible
with the various SDR programs.

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Re: [KX3] ADC/DAC access, keyer input

Oliver Dröse
As the I/Q output will only have a bandwidth of something in the 30-50 kHz
range or so as Wayne told earlier this summer every standard soundcard will
do the job, so no need for a 192 kHz capable device. ;-))

73, Olli - DH8BQA



----- Original Message -----
From: "Jessie Oberreuter" <[hidden email]>
To: "Christian KJ4VPK" <[hidden email]>
Cc: "Edward R. Cole" <[hidden email]>; <[hidden email]>
Sent: Saturday, August 20, 2011 11:14 PM
Subject: Re: [Elecraft] [KX3] ADC/DAC access, keyer input


>
> On Fri, 19 Aug 2011, Christian KJ4VPK wrote:
>>
>> Trouble is today that 192 KHz USB sound cards are hard to come by
>> (although the chipsets are widely available) and the same is true for a
>> 192KHz sound card in the laptop/PC unless we are talking high end
>> (=power hungry) hardware. Oh well. Screams for an aftermarket gadget.
>
>      I would normally think that competing in the USB dongle market would
> be folly, but if there really is a gaping hole here, perhaps Elecraft
> could fill it -- especially since they've recently waded into the
> production side of such toys :).
>      I do appreciate the need: I recently watched Ki7el, who is an IT
> professional by day, struggle to find a USB soundcard for his recently
> completed Ensemble transciever that offered stereo bit-rates compatible
> with the various SDR programs.
>
> ______________________________________________________________
> 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
>
>
> -----
> eMail ist virenfrei.
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>

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Re: [KX3] ADC/DAC access, keyer input

John Ragle
In reply to this post by Jessie Oberreuter-2
WRT 192 kHz sound cards in general (I don't understand why one would
want USB???) there are several US manufacturers. The Infrasonic Quartet
4 channel 24-bit 192 kHz PCI card is my favorite, and the claims by
several vendors (NewEgg, etc) that this is not available are false: the
manufacturer is viable and in active business.This card works very well
with the several SDR products that I have at hand.

John Ragle -- W1ZI

=====

On 8/20/2011 5:14 PM, Jessie Oberreuter wrote:

> On Fri, 19 Aug 2011, Christian KJ4VPK wrote:
>> Trouble is today that 192 KHz USB sound cards are hard to come by
>> (although the chipsets are widely available) and the same is true for a
>> 192KHz sound card in the laptop/PC unless we are talking high end
>> (=power hungry) hardware. Oh well. Screams for an aftermarket gadget.
>        I would normally think that competing in the USB dongle market would
> be folly, but if there really is a gaping hole here, perhaps Elecraft
> could fill it -- especially since they've recently waded into the
> production side of such toys :).
>        I do appreciate the need: I recently watched Ki7el, who is an IT
> professional by day, struggle to find a USB soundcard for his recently
> completed Ensemble transciever that offered stereo bit-rates compatible
> with the various SDR programs.
>

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Re: [KX3] ADC/DAC access, keyer input

KK7P
In reply to this post by Oliver Dröse
There are a number of technical as well as practical reasons why the IQ
output from the KX3 is buffered analog rather than USB.  Or Firewire, or
Thunderbolt, or Ethernet, or S/PDIF, or AES3 or one of the other myriad
digital standards...  Some of these reasons are likely to become more
apparent once the KX3 is shipping.

There was careful consideration of the implications and tradeoffs before
the decision to provide a buffered analog output.

Meanwhile, for those so inclined, the available analog IQ stream will
provide a simple means of applying PC-based SDR techniques to the KX3
receive path.

73,

Lyle KK7P



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Re: [KX3] ADC/DAC access, keyer input

Dave KK7SS
In reply to this post by gmaxwell


--
Dave G  KK7SS
 Richland, WA

'59 Morris Minor 1000 - working on it..
'65 Sprite - in process :(
'76 Midget - co-owned with #4 Son :)
'06 Honda Civic Hybrid
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Re: [KX3] ADC/DAC access, keyer input

Dave KK7SS
In reply to this post by gmaxwell
Lyle wrote:
> There are a number of technical as well as practical reasons
> why the IQ output from the KX3 is buffered analog rather than USB.
> Or Firewire, or Thunderbolt, or Ethernet, or S/PDIF, or AES3
> or one of the other myriad digital standards...

"The great thing about standards, is that there are so many of them!"

--
Dave G  KK7SS
 Richland, WA

'59 Morris Minor 1000 - working on it..
'65 Sprite - in process :(
'76 Midget - co-owned with #4 Son :)
'06 Honda Civic Hybrid
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