DRAWS for KX3 IQ capture


Troy - K4JDA
 

Basil, John, and team, thanks for all you do to support the NW Digital products!!  Much appreciated!

My KX3 outputs an IQ signal and reportedly a stereo sound card that captures 24 bit 192kHz is ideal for pulling in the data.  Does DRAWS meet this spec?  If not, what sampling rate can I squeeze out of my DRAWS hat?


Basil Gunn
 

Read the application guide for the TLV320AIC3204
https://www.ti.com/lit/ml/slaa557/slaa557.pdf

The device that DRAWS uses is a 32 bit 192kHz DAC so more than meets
your spec.


Troy - K4JDA <troy.davis@...> writes:

Basil, John, and team, thanks for all you do to support the NW Digital products!! Much appreciated!

My KX3 outputs an IQ signal and reportedly a stereo sound card that
captures 24 bit 192kHz is ideal for pulling in the data. Does DRAWS
meet this spec? If not, what sampling rate can I squeeze out of my
DRAWS hat?


Annaliese McDermond
 

Be careful about this.

Yes, there is a 196ksps sample rate in the tlv320aic3204.  I made sure the driver supported that when I wrote the code to expand the sample rates.  If you notice in the application guide, though, the antialiasing filter for the 196ksps sample rate cuts off at 20kHz.  So, if you are expecting to see pandadapters that are 192kHz wide on your display, you won't get them.  There'll be rolloff at 20kHz.  See the description of filter C on page 30 of the aforementioned application note.  If you want to see wide pans, go with 96kHz which should work okay from the filter descriptions there.

--
Annaliese McDermond, NH6Z