Survey and summary: Elecraft K3/K3S panadapter solutions

classic Classic list List threaded Threaded
3 messages Options
Reply | Threaded
Open this post in threaded view
|

Survey and summary: Elecraft K3/K3S panadapter solutions

Dick Dickinson
Ever the contrarian here, I note the KX3 has I/Q output.  Why not a module
for the K3/S rather than the P3..?


Dick - KA5KKT


______________________________________________________________
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]
Reply | Threaded
Open this post in threaded view
|

Re: Survey and summary: Elecraft K3/K3S panadapter solutions

Dave Fugleberg
 As I understand it, the KX3, and the P3, both contain a software defined
receiver, so the I/Q signals are already present.

That is not the case for the receiver in the K3 or K3S, so adding it there
would involve adding a SDR.
On Fri, Jul 27, 2018 at 2:21 PM Dick Dickinson <[hidden email]>
wrote:

> Ever the contrarian here, I note the KX3 has I/Q output.  Why not a module
> for the K3/S rather than the P3..?
>
>
> Dick - KA5KKT
>
>
> ______________________________________________________________
> 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]
>
______________________________________________________________
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]
Reply | Threaded
Open this post in threaded view
|

Re: Survey and summary: Elecraft K3/K3S panadapter solutions

Don Wilhelm
Dave and all,

The answer to your assumptions depends on *your* definition of I and Q
signals, and also your ability to separate analog I/Q concepts and
digital I/Q concepts.

I believe the K3/K3S, KX3 and KX2 already qualify as SDR transceivers -
but they do the DSP signal processing inside the box without any
dependency on an external computer.  Some seem to think that to be an
SDR, you must connect with a computer - I do not share those thoughts,
an SDR is all about mathematical processing - study a bit on DSP, that
is "what it is all about".

I and Q signals can be defined as 2 identical signals but 90 degrees out
of phase - period (full stop there, anything more is what adds
confusion).  One can do "magic" with those two signals, and create
filters, demodulate, modulate - all by manipulating the signals in the
digital world.  It can also be done in the analog world (examples, Rick
Campbell's phasing receivers, and the old phasing SSB exciters)

The K3/K3S does have I/Q signals, but they are digital and are at 15kHz,
not audio, so one cannot feed them to a computer soundcard.
The KX3 has I/Q signals (and I/Q outputs) because the I/Q signals are at
baseband (audio frequency spectrum).  The onboard computer (MCU) inside
the radios do the processing rather than depending on a computer
soundcard and the computer MCU for the processing.  The KX2 is similar,
but has no I/Q outputs.

While some want to add their favorite computer software application to
do I/Q processing separate from that done by the K3/K3S or KX3 or KX2.

The current fact is that the K3 I/Q signals exist, but they are only in
the digital world.  The P3 does extract them, but for purposes of the
P3, they remain in the digital world.
Getting those signals into the analog world will take some work and
design effort.  It is more complex than a digital to analog converter.

73,
Don W3FPR

On 7/27/2018 5:17 PM, Dave Fugleberg wrote:

>   As I understand it, the KX3, and the P3, both contain a software defined
> receiver, so the I/Q signals are already present.
>
> That is not the case for the receiver in the K3 or K3S, so adding it there
> would involve adding a SDR.
> On Fri, Jul 27, 2018 at 2:21 PM Dick Dickinson <[hidden email]>
> wrote:
>
>> Ever the contrarian here, I note the KX3 has I/Q output.  Why not a module
>> for the K3/S rather than the P3..?
______________________________________________________________
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]