--- In [email protected], "trgkrazytrev" <[EMAIL PROTECTED]> wrote: > Ok laugh at me but i am a complete novice at this, Im building a > software radio for my final year project at university. > I have just build the front end that alberto shows in his > photos and i was wondering how do I tune into a desirred > frequency for example 97.4MHz on fm
Dear ??? (what's your name?) there are a few considerations that must be done. What I did put on the pseudo-schematic is just that, a pseudo-schematic. Not all of the connections are shown, e.g. the 74HC74 lacks some wiring between some pins. My intent was just that of giving an idea of how my circuit worked, not that of providing a detailed set of instructions sufficient to replicate it. A second point is that probably the components I used are not adequate for a frequency of 97 MHz. I don't have in this moment handy the characteristics of the ADG704 (the analog demultiplexers used for the Tayloe QSD), but probably their switching time leaves something to be desired for that frequency. Thirdly, an FM signal at 97.4 MHz has, with all probability, a wide deviation, more than 100 kHz. The SDRadio FM demodulator is meant for narrow FM, a few kHz, as used by radioamateurs. I would suggest you to give a look to another software defined radio project present on Internet, namely gnuradio, found at http://www.gnu.org/software/gnuradio/ They have developed demodulators for a lot of modulation schemes, even HDTV ! They sell also an hardware board that works with their software, which, BTW, is Linux based (which can be a cursing or a blessing, depending on your preferences...) 73 Alberto I2PHD P.S. I will be away from having Internet access for a couple of days, so there is the possibility that a few messages will wait for approval and not show immediately, Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/soft_radio/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
