[Discuss-gnuradio] Re: The ultimate SDR

[Ian Wraith]

Hello
     I have also been giving some thought to the design of a SDR of
late. Although I don't want an "ultimate SDR" just a starter SDR that will
allow me to experiment cheaply. So I was thinking along the lines of a AD9870
IF digitizer which has a 10 to 300 MHz input and outputs a digital I & Q.
This would be feed into one of the faster PIC's which will then pass the 
data on to a PC for processing via USB. Tuning info will be sent from the
PC to the PIC via USB which will then tune the AD9870. 

 This method does have a number of drawbacks the main one being the 
limited bandwidth of the AD9870 (150 KHz) so any GSM use is out of the
question. Other drawbacks being the device comes in a 48 pin LQFP package
so it would be difficult to work with plus I never have enough time.
If I ever get round to building such a circuit I don't want to re-invent
the wheel so has anyone ever built anything like this before ? If so did
you come across any problems I should be aware of ?

Thanks

Ian