Gene, you are absolutely right! I just did some more research and found current SDR tech (high priced) is doing 8 MS/sec into USB 2.0.

So now I see some people sampling the analog IQ output using 24 bit A/D sound cards and think they are getting high resolution dynamic range. I am wondering what the original analog IQ output is derived from. Is it 14bit? If so these guys are fooling themselves. Does anyone know?

Regards all for a 73 New Year
DJ WK1K/ex-KB1YOO/W8PID

Gene
Actually the SDR-IQ samples the input at 66 MHz. The limiting factor is cramming the samples through the USB. So that's probably why only 192k. I think the newer SDR devices do simultaneous on board multiple channel demod with FPGAs. But now that's getting expensive. 192k is big enough bw for my poor addled brain to see what's around. So not the best but good enuf for amateur work!

DJ WK1K previously known as...this & that

OK Somehow I have stumbled into the truth! Bottom line is (happily) the KX3 DOES do 196kHz bandwidth and I finally got it to work.  Remember that there are TWO IQ audio lines to sample at 192k each, which give you a BW of 96k each side of center .. sum total BW = 192k. So you set your sound card to stereo line in sampled at 192k. And then use your favorite program and it should display properly.

Here's what I did specifically..
.. used an old 2008 MacBook laptop dual boot running Windows 7 standalone.
.. configured sound card for stereo line in 16 bit 192k sample rate.
.. ran KX3 RX I/Q cable direct into stereo line in
...40 meters was pretty active so I tuned the KX3 to 7200 kHz
.. ran SDR-RADIO app
.. before hitting the start button, set up the BW display (right click) in the app for 200kHz
and set input for the Soundcard option then select line in as device @ 192k sample rate
… also INVERT the IQ
.. click the Start button
.. the waterfall will start and always be centered at the current KX3 frequency
. .if you tune the KX3 up in freq, the waterfall should shift left
.. The waterfall display will show funny frequencies on the bottom..ignore them and don't mess with the ham band buttons or you will lose the waterfall.

Then I started up another copy of SDR-RADIO and attached to my local SDR-IQ. I also connected to the same antenna. I centered the SDR-IQ freq to same as KX3 and voila! Both waterfalls pretty much matched. It looked like there was a spurious signal reflected off center at +- 40 kHz. It didn't move when I tuned freq. Probably need to use the I/Q balancing utility in SDR-RADIO.

I also ran the HDSDR app with KX3 input and got the same bandwidth pattern results..

Then I plugged the KX3 IQ into the iMic and connected to the USB on my laptop. I couldn't get more than 48kHz bandwidth. I am using the iMic on my iPad so it is good enough for now.

So if your laptop sound card can do 192k stereo per channel sample rate, you are probably good to go. Otherwise just buy one of the high performance USB sound cards (but NOT iMic).

So have fun.. now I am starting to think my SRD-IQ is redundant.

DJ - WK1K previously KB1YOO previously W8PID

What happened to this thread?.. It was getting really interesting and then everybody ran out of gas. I just bought an SDR IQ and a KX3 and interface to an iPad using iSDR. Hey NI0Z your photographs are really incredible.
You also have the right perspective in your outlook. As a new ham you are Asking the right questions. As for myself, I got licensed at 13 in 1953 and the let my license lapse when i worked overseas. I finally got relicensed recently so i am looking at things from your point of view.  Don't let the arrogant engineers deter your initiative. I have run into these guys before and they think the world revolves around them instead of an actual product. Don't get me wrong, these guys are good at what they do but are never in charge of reality. There are some guys who think you don't know how to program unless you use UNIX with a Black and white text terminal.  Hi hi

So relative to your link on the KX3 bandwidth, I keep experiencing inconsistencies. From what I read, I believe the maximum possible KX3 IQ bandwidth display is 192kHz with a sample rate of 192kHz. The KX3 manual states this rather obtusely. I have to say that I have never seen any of the popular SDR programs show a KX3 bandwidth spectrum of 192kHz. I cannot get it to work either.  Maybe it's me.

Regards, WK1K previously KB1YOO