[hpsdr] About the Dynamic Range of Receivers

[pvharman at arach.net.au]

Hi Jeff,

Ray is correct, we intend to directly sample the incoming signal rather than 
mix down to an IF prior to the ADC. 

Some very preliminary performance calculations are on the Wiki at 

http://hpsdr.org/wiki/index.php?title=MERCURY

Please let me know if you find any errors in the calculations. 

73's Phil...VK6APh 


Quoting Ray Anderson <ray.anderson at xilinx.com>:

> ***** High Performance Software Defined Radio Discussion List *****
> 
> 
> 
> Jeff, WA1HCO wrote:
> 
> 
> >the approach of using a single QSD mixer helps a lot.  I didn't see
> what >the Mercury board intends for the buffer between mixer and A/D,
> but with up >to 0 dBm input level, it seems to need more than +45 dBm
> OIP3 to keep up >with the A/D.
> 
> >This is a very cool project.
> 
> >jeff, wa1hco
> 
> 
> Jeff-
> 
> I don't think the Mercury board details aren't completely worked out
> yet, however I believe that there is no mixer between the antenna and
> the A/D.  There may be a high OIP3 preamp in front of it, but the A/D
> will directly sample at the incoming RF frequency.
> 
> 
> 73 de Ray	WB6TPU
> 
> 
> 
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