> Actually guys i am building the receiver portion only, could you > please please please tell me what i will have to do between my > antenna and adc. I will do the processing in computer. Adnan, I'm not too sure what you mean by the ''only'' part. I would tend to think that the adc is your 192kHz computer sound card.
You can take a look at some projects at the below link for the carrier frequency of interest http://uwsdr.berlios.de/hardware.html This part http://www.analog.com/en/prod/0,,770_849_AD8348%2C00.html is a I Q downconverter with integrated variable gain with I Q outputs. For filtering, you could use a ready-built product to get only the FM band. There are some alternatives if you want to learn and build one. A)You can get a SAW filter http://www.rfm.com/products/sawfilters.shtml?source=GoogleAdwords http://www.epcos.com/web/generator/Web/Sections/ProductSearch/ProductParameter/SAWComponents/Multimedia/BandpassFiltersTVApplications/Page,templateId=render,locale=en.html B)David Brainerd on this mailing list made a filter circuit board with several bands, but for lower frequencies. He might be able to point you to a good design. You would need to be aware of parasitics and spend time testing your components. C)You could also build a fairly large one with sheet metal in the spirit of: http://www.tinlee.com/FM_Products.php#FULLFM D)Transmission line filters. The idea is to cut the length of coaxial cables and combine them according to the 1/4 wavelength of the carrier. Frank
