Selecting a new SDR

Carl, Good to hear from you, and good to hear your interest (in this note, and your later ones). Congrats on your progress with the SRT. There are a lot of people struggling with these things. We are still pushing the technical possibilities and seeing what we can do. I think that you are getting the idea of what some of our challenges are, and our difficulties. Our development of ideas and how to work with no budget has led us along several paths -- this becomes a multidimensional array, and a good summary is our most recent (June, 2011) writeup at rf-sampler (a yahoo group that I hope you'l join). First the budget part, and this will just consider hardware, not the software part or everybody's donation of time: One zero dollar cost path was my begging parts from TI and Paul's pulling stuff from his project bin/workbench. This is going along well. A second path is gradually pulling parts together for a circular polarization radio astronomy experiments in the LF/VLF spectrum, based on ideas I discussed at the SARA conference. A third path, very important, may be that we all work through SARA to purchase parts for the RFSDR. A fourth path may be to get some investors who will benefit from the ultimate product, and who will throw some seed money into the pot. The RASDR project technical progress is being pursued in 3 phases. Basically, we started with an ambitious project that would use an FPGA board of our design. Early investigation led to our designating this as Phase 2. Phase 2 will be high speed -- a very hot receiver. More immediately, Phase 0 will center on a Lime Micro advanced chip (cost $65) on a board of our design and a USB 2.0 interface board (cost under $100); Phase 1 will be something with an FPGA, but not optimized. We got very active for the SARA June meeting, and MUST do this again in preparation for our Oct. 22 SARA regional meeting near Knoxville. Please see radio-astronomy.org on the home page and click the "regional meeting" to get the call for papers. I hope you'll come. See our SARA paper (in the proceedings, presented by Paul Oxley, and included in files at the rf-sampler yahoo group) for our original concept, which has become Phase 2, and some of our needs for Phases 0,1, and 2. Our first serious product will probably be Phase 0 (needed to do the engineering: one Lime Micro board and one USB interface board). Phase 0 is a most important step which we need to begin immediately. We need to work through SARA or get buy-in from serious amateur astronomers to fund purchase of the two needed boards. "When??, you ask. Please give us a few days to try to answer that. David Fields