Re: [Discuss-gnuradio] Welcome and brief update

[Marshall White]

--- Daniel Rogers wrote:
> actually, it seems that I choose 40Msps from a lack of understanding of 
> the amount of samples/Hz of radio frequency needed for correct digitization.
> 
> That said, how is it that a 400 kHz sample rate is sufficient for a 
> 107.5 MHz FM modulated signal?  How is it that you can extract useful 
> information when you have much muhc less that one sample per cycle.
> 
> And given all this information, what is the max frequency you could 
> demodulate at 40Msps?
> 
> --
> Dan
> 

Dan,

The answer is that you must have a "tuner" that takes the signal at 107.5 MHz 
and "moves" it down
to a much lower frequency (called an IF, or intermediate frequency).

If you have a 40 MHz sampling rate, any IF less than 20 MHz should more or less 
be okay.

If you had a 400 kHz sampling rate, then your IF would have to be CENTERED at 
100 kHz.

Marshall