Using Sodira with SDR-IQ for C-QUAM decoding.

[jFarley]

I wanted to give Sodira a try with my SDR-IQ for decoding C-Quam stereo transmissions.  While this appears to be possible, I could not find any firm procedure for setting it up.  Cobbling together info from various forums and sites, I have come up with this procedure.  It works for me on my OS (Vista) with my soundcard (I use an external Sound Blaster X-Fi).  Maybe it will work for you.

Note that this took a bit of doing, and seems to be pretty reliable.  If you do not feel comfortable shooting down cranky apps and processes with Task Manager, this may not be for you...

Download and install the software.  

1) Using Windows Explorer, create a folder such as /Sodira
2) Download the Sodira files from http://www.dsp4swls.de/download/download.html and place the archive in this directory.  I used
    version 0.092
3) Extract the files to this folder.
4) You will need an additional DLL to communicate with the SDR-IQ.  Go to the Winrad homepage at http://winrad.org/ and download
    the file from the link "Download the support files for the RFspace SDR-14 and SDR-I/Q receivers."
5) Download these support files to your folder and extract all.

Getting it to work can be tricky.  Everything worked fine the first time I tried to configure and run Sodira.  There was a problem with all subsequent restarts.  When Sodira is closed, either Sodira or the support DLL will leave a file named "ExtIO-SDR14_IQ.ini" in your folder.  It appears that this file can cause problems (cause the DLL to throw exceptions) if it is there when starting Sodira.  The following seems to be a workaround to that problem.  Using this procedure, I can get Sodira to start reliably without crashing.

1) Detach the SDR-IQ from the USB port and reattach it.
2) If there is a file in your folder named "ExtIO-SDR14_IQ.ini" DELETE IT.
3) Start Sodira; there may be a dialog complaining about an exception in the DLL.  Close it and ignore it.
4) Click on the "Configuration" button in the Sodira window.
5) Click the "Wavedevice" tab page make sure that your sound card is selected.
6) Click the "Receiver" tab page.
7) Make sure that the "Using External IO DLL" checkbox is unchecked.
8. In the "Internal Receiver" drop down box select "No Receiver, IQ Data From Sound Card"
9) Click the "HW Init" button; Sodira should start, but it may just buzz.
10) Check the "Using External IO DLL" checkbox.
11) Click the "Load ExtIO" button.
12 Select the ExtIO_SDR14.dll file from the resulting file open dialog.
13) Click the "HW Init" button.  Sodira should now be running properly.

To get CQUAM stereo

1) Select "AM Radio" in the drop down box in the lower right corner of the Sodira window.
2) Click the "Dialog Window" button just above the drop down.
3) Click the "Stereo (C-QUAM) button.  That's it!

[redhat]

I've had similar trouble with winradio.  As such, you are supposed to have some sort of control over the receiver using the sodira interface.....nada here.  Sodira runs merely as a software audio decode device, using an I/Q winradio output plugin which you need to get from winradio, and to my knowledge, isn't posted anywere.  The winradio driver creates a "virtual soundcard' which sodira can look at to get its I/Q baseband.  After that, you have to play with sample rates and the windows default sound device to get all to behave.  To make matter worse, I wind up with buffering issues using my echo mia cards.  using the onboard sound seems to work much better, and this isn't a new problem in my realm.  I've actually had better success decoding cquam using a netbook with the winradio frontend and sodira alongside the onboard soundcard.  Note that these troubles relate to winradio 305 and its associated software with professional plugins.  Excalibur users may have better luck, and supposedly there is a development plugin from winradio that includes cquam decode, but you have to ask for it, it is not an official release.

Lots of luck, I may wind up making (and selling) hardware CQUAM/ISB decoders for Drake R8's before its all said and done.

+-RH

[jFarley]

I haven't given up on Sodira yet.  It at least works here, and I have receiver control.  I have yet to get it to properly record audio files out of the program.  I have to run Audacity in the background to capture audio which is nice because I can see what is being recorded.  But this, I think, may be part of the performance issue I'm seeing.  There certain Audacity functions which appear to be running modally, and this may be screwing up interrupt servicing in other apps?

I want to play around with resetting process priorities while I'm running this setup; running Sodira, Audacity, a browser, and whatever just seems to be too much, which results in Sodira barfing.

Having an outboard decoder would be a great thing, and we look forward to that.  The best solution for me would be if SDR Radio added C-QUAM capability.  I have gotten spoiled by SDR Radio because it really is a great app IMHO.  It seems very robust and reliable, and has an extensive feature set which really enhances productivity.  The extensive use of autohiding pinnable dockable windows (much like the Visual Studio interface) puts a lot of functionality right there on the desktop.  Common tasks such as capping or viewing screens, viewing a greyline map, or checking STIs can be done with one click.  The SAM decoder I find to be very good, if not great.  Very highly recommended if you have an RF Space SDR and Windows.

[redhat]

Oh, I missed the part about vista....not the most stable platform ever made.  Still XP here

+-RH

[Kilokat7]

For Perseus:

Perseus > Virtual Audio Cable > Sodira > Enjoy C-QUAM!

1) Set Perseus to "USER" mode (which dumps raw I/Q to VAC)
2) Set Sodira Internal Receiver option to "No receiver, I/Q data from sound card"
3) Set Sodira's Demod to "AM Radio", hit the dialog window button & select "Stereo C-QUAM"
4) Enjoy X-FM's AM stereo broadcasts :-)

 jFarley: What control software do you use with the SDR-IQ - SDR Radio?  Is there not a similar function to dump the I/Q stream to a program like VAC?  If so then this may save a lot of frustration instead of trying to make Sodira control the receiver on its own.

[skeezix]

Why use Perseus s/w+VAC as well? I use SoDiRa directly with the Perseus radio and it works great. It demodulates C-QUAM (and DRM, others) and have control over the radio.

Also can save the I/Q data to a Perseus format file for later use. However, SoDiRa can't read that file and Perseus/Studio 1 don't decode C-QUAM. Can use regular AM/SAM from those programs to listen.

[Kilokat7]

I use SoDiRa directly with the Perseus radio and it works great.

This is news to me - please explain how to set it up.  I see no Perseus option under the "Internal Receiver" configuration - maybe your using an external IO DLL to control the Perseus hardware?