I was wondering if there were any good Open Source SDR radios out there. What I mean by this is that I would like to be able to code my own IF and AF DSP filters, modify the GUI, etc. rather than being locked in to something like the 7300 (which I have). With the Flex or Anan can you actually tinker with things under the hood? Or are you stuck with what they give you? Maybe something like GNU Radio? Alternately a kit or homebrew project would be cool. I am not at the level where I would want to design it from scratch, though. Anyone have any experience with such a thing? Basically, I like old rigs because I can get in there with a soldering iron and modify things to my liking. I'd like an SDR rig where I can get in there with a text editor (and the source code) and modify/enhance things. Thanks.