[Elecraft] KX3 SDR

[Don Wilhelm]

If you are writing your own software, you will have to become proficient 
in Digital Signal Processing.  The I and Q signals are simply baseband 
signals that are 90 degrees out of phase - by themselves, they will do 
nothing but audio signals, but with DSP processing, they can do most 
anything that is possible in the math of digital signals - limited only 
by your processing power and skills at DSP signal processing.

Run them through FFT transforms to convert them to digital signals, and 
then do the math of your DSP algorithms to produce whatever you want - 
panadapter display, demodulation, etc.  You can add filtering and other 
things like AGC, Noise Reduction, Noise Blanking, and a whole variety of 
effects.  It is all in how you choose to implement you DSP mathematical 
functions.

Rather than write your own, there are several DSP applications available 
for free or at nominal cost - try HDSDR or NaP3 or WIN4K3 as examples.
Once you see what is happening with those applications, you may be moved 
to write your own DSP application to process the I and Q signals.

73,
Don W3FPR

On 7/27/2016 7:16 PM, Enzo Adrian-Reyes wrote:
> Hi All
>
> Yes this topic might be a little bit more complicated than the title
> suggest.
>
> So I have the KX3 plugged into the audio input of my computer, and its
> sending quadrature data (IQ) to the sound card, the sound card samples at
> 96Khz.
>
> So my question is how I process this? Yes I know use a piece of software,
> but I am trying to write this, I know the IQ data is coming through down
> and if I use the right process on the IQ data I get base band data out. I
> kind of know that however I dont understand the SDR data coming out, so for
> example and I getting sample of IQ data at freq point Y, or is it  a
> circular buffer arrangement.
>
> I guess what I am saying is, is the IQ data coming from teh KX3 data from
> teh Centre Freq (+/-) the bandwith scope, or just the centre freq + some
> additional side bands?
>
> How are bandwith and sampling rate related? I mean if I am sampling at at
> 96Khz, with a band with of 48Khz does that mean I am only getting 2 samples
> per second at perticular freq??? Or am I getting the entire band of 48Khz
> at 96Khz.
>
>