[hpsdr] graphic cards and sdr

[jeff millar]

alex wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> here is some info i found on the ramdacs of graphics cards
> does anyone else think that it would be possible to use the ramdac for 
> an sdr? eg 230mhz at 16bit
> just add an adc and you could impliment the whole of an sdr on a 
> graphic card
Now all you have to do is figure out how to use the horizontal and 
vertical sync pulses constructively. If not, your SSB signal will have 
nasty buzz :-)

Seriously, it's a good idea. _If_ it's possible to generate a continuous 
waveform without H or V artifacts, then the next step would be to 
measure dynamic range, two tone IMD performance and noise floor.

Ok, now what do you do with 3 outputs? Red and Green for I/Q and Blue 
for the LO, maybe??

One more issue, they only use 8 bit DACs, so the output will have some 
artifacts.

jeff, wa1hco



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