Martin, my objective is to do as much as I can in software/FPGA. That is, I get the digitized antenna feed (the ADC input stage itself will probably require a LPF, but that's it), tune/detect/filter it using DSP magic, and spit out some sort of signal to an audio DAC. I realize that this is not the way "proper" radios work. The reason I chose AM is that its frequency band is still digitizable - I don't have to mix it down like I would with FM or whatever. But I'm still reading as I go, and you're right, it may be unfeasible the way I have it planned right now. Thanks, - Marcel What's your front-end look like? > You can't just feed an antenna into an ADC and expect to get a good > signal (or any).. I'm not an RF guru but you at least need an input > filter (band-pass) and maybe (maybe, it's a modern idea) - just a > first-stage amplifier if you're going for direct conversion. I'm not > sure if this works the same for AM. I'm not an RF wizard. > > Normally, an RF amplifier has a local oscillator (or two) that gets > mixed with the input signal. A low pass filter then removes the high > frequency parts so you're left with audio-range frequencies. You'd then > only have to sample at something like 48kHz. > > If I were you I'd first work on how you're going to receive the RF in > the first place. Get an ARRL Handbook and also read about the > "SoftRock-40" project. > > - > Martin > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist