[Elecraft] Fun with K3, SDR-IQ, PowerSDR and HRD

[Aerospace PoP Mail]

The good folks at RFSpace (makers of the SDR-IQ and SpectraVue) have modified SpectraVue to make it compatible with CW Skimmer (by making the I/Q output from the SDR-IQ look like a soundcard).  While I was fooling around getting CW Skimmer to work with my SDR-IQ, it occurred to me that it should be fairly easy to use the SDR-IQ as the digital frontend for PowerSDR and use PowerSDR as a nice panadaptor for my K3 (as well as many other things ...).  Here's an idea of what worked for me (make sure you have the latest releases of the software):

 

Configure a Virtual Audio Cable (VAC) with the following settings:  SR 46000 .. 58000, BPS 8 ... 32, NC 1 .. 2, Ms per int 1, cable format.

 

Configure SpectraVue for 50 KHz sample rate, Dual Channel Stereo Output, turn off Demod, and select Virtual Cable 1 (if that's what you set up as above) as the sound card, center frequency 8.215 MHz.

 

Configure PowerSDR as follows.  General tab - select SDR 1000, Rx only, DDS (expert) set IF to 0.  In the Audio tab, select unsupported card, Driver - MME, Input Virtual Cable 1, Output - whatever your sound card output is, Mixer - none, Buffer size - 2048, Sample Rate - 48000

 

First start PowerSDR, then SpectaVue.  You should now have PowerSDR processing the I/Q output from the SDR-IQ.

 

Using the K3 IF output as input to the SDR-IQ, I now have a pretty nice panadaptor (two, including SpectraVue) and all the receive capabilities of PowerSDR (variable filters, dual receive, NB, stored memories, etc.).  Using the Ham Radio Deluxe (HRD) synchronization feature, I can "slave" the K3 to PowerSDR and use PowerSDR to control frequency, or, making PowerSDR slave, tune with the K3.  I'm sure there are many more features and interesting things to do with this combination, but that's all I had time to do during my lunch hour.  There may be more eloquent ways to accomplish the same thing, but I just cobbled this together with what I had.

 

Is it possible for PowerSDR to control the SDR-IQ through HRD?  I haven't tried it, but I think so.  Or have HRD do it directly?   



As Ed, W2RF, has pointed out, there may be subtle issues with the rate resampling that VAC does.  So far I haven't noticed any effects in PowerSDR, but I haven't had time to look very hard.  I also wasn't able to make any higher sample rate work (96KHz or 192 KHz) in the limited time I had.  I suspect some buffers somewhere are overflowing, but I don't know.

 

Joe N6KK