If your main use for this board is going to be broadcast FM, I would
strongly urge you to use a fixed oscillator and a simple mixer to
downconvert the received signal into a range that avoids alias.  The fact
that FM broadcast band is split by a fold when used for direct conversion
makes it a bit challenging for such a purpose; you're going to get alias
images no matter how much filtering you do.  Since the FM broadcast band
covers 87.9 to 107.9 MHz, you need an oscillator somewhere between 75.9 and
87.9 MHz to ensure that the entire downconverted band falls below the first
aliasing fold point.  You would also want to use a bandpass filter so you
don't end up with aircraft transmissions creating alias images.

Or you could just use one of the other daughterboards. :)

Kelly


On Thu, May 22, 2008 at 11:34 AM, isaacgerg <[EMAIL PROTECTED]> wrote:

>
> It looks like i need to get an RF front end to pre-filter all that stuff
> out
> of there.....
> --
> View this message in context:
> http://www.nabble.com/BasicRx-Daugterboard-Frequency-Wrapping-tp17375343p17408282.html
> Sent from the GnuRadio mailing list archive at Nabble.com.
>
>
>
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