[hpsdr] CASMIR design v0.4 plus introducing COPERNICUS!

[Alex]

An updated design document for CASMIR can be found at http://www.hamsdr.com/personaldirectory.aspx?id=321

I've significantly changed the design, replacing the DDS-generated LO with a DDS/Divide-by-N PLL generated LO (coarse and fine loops), added an H-mode mixer, substituted the DAC and created a new front-end board for the bandpass filters. 

The front-end board, named COPERNICUS  shall provide the option of T/R switching or use two boards for separate transmit and receive. It will be used as a front-end for CASMIR, HORTON, and MERCURY. Form factor and placement of the card are up for discussion. Personally it seems like a waste to use an ATLAS slot for COPERNICUS, maybe an external card. There's lots of room in my ATX case to mount it!  : )  (hint, hint, hint)

And for the nomenclature fans out there, why COPERNICUS? There's 9 HF bands and 9 planets, thus COPERNICUS. Plus it's starts with a "C".  : )   

Alex, N3NP