I'm now shifting back to my real love, which is building radio equipment from scratch. My current project is going to be an SDR-Cube by George Heron, N2APB and designed by Juha Niinikoski, OH2NLT. I hope to contribute hardware (probably PA's) and software (DSP notch filter) to the project eventually. I'd also like to port it to the 32 bit PIC's...the PIC32MX series. That could take some effort and I'm not sure if I'll have spare time to get there.
I think it is actually SDR done right. I could go in to the problems I have had with my FlexRadio Systems FLEX-1500.. but that's only been like teaching a pig to sing. It only annoys the pig and it still doesn't sing. I've never seen a group quite so defensive of a technical product as the users of their radios. The company is a bit better, however, and does try really hard to provide service to the customers. I had a good, quick turn around on my 3-month old Flex-1500 when the PA stopped functioning on 20 and 30m. Now that the newest software works (2.0.16) software is acceptable (first version that was for me) and the rig was fixed and tweaked a bit, I had fun with it on QRP PSK-31 last weekend. I will admit that the IMD reported was the best I ever received.. so the DSP does do it's magic...It's just that the almost five months it took me to get it working right (and I do this for a living, remember) really soured me on the "Flex" "PC" approach to amateur SDR. If only a DSP had been part of the design.. sigh...
Unlike the Flex philosophy, the SDR-Cube uses a dedicated DSPic33.. a 16-bit device to do real time (and therefore low latency) operations. Ham radio, particularly at HF and even above in what hams currently typically use do not use much bandwidth and therefore don't need much processing power. The Flex and other PC based topologies (like the Softrocks, Genesis radios, etc.) rely typically on Windows for the platform to do DSP on. Windows has about the worst deterministic qualities of any OS out there, so random delays can interrupt the DSP that is on going. So literally your requirements for a dual-core PC (and an AMD one at that) to properly operate a Flex-1500, 3000, 5000 are really emulating the processing power of the PIC on the SDR-Cube that is dedicated to the task of demodulation. It's rather a testament of the effort that the Flex team has put into PowerSDR that it works as well as it does. However, it's not the correct way to do the SDR in my humble opinion.
I'm hoping that the Software that Juha has done in the SDR-Cube is the basis for much growth. I think he's done it correctly for current ham bandwidth signals.
We will see..
George Heron is always a blast to work with. I wish I could be 1/2 as positive as he is all the time..
I've started this to 'blog site to document the build of this project and maybe update some of my activities and other projects. Anything that comes out of that that should be saved for prosperity will end up on my website: fredspinner.com. It needs to be updated.. it's hopelessly out of date but I'll try to fix that in 2011.
It's Christmas Eve.. and the wife and kids are getting anxious. Merry Christmas to all and Happy New Years.
73,
Fred M. Spinner, W0FMS
*the small tower. It's a lot better than nothing.. which is what I had for years...
** I'm kicking around the idea of joining QCWA... at 41.. I'd have to be one of the youngest members...I am eligible 1/1/11 :O)
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