Re: [Discuss-gnuradio] New Software Defined Receiver soon to be available

[Marcus Leech]

Philip Covington wrote:
> Highlights:
>
> 16 bit 130 MSPS ADC
> HPF, LPF, RF AMP Switchable Front End
> 0-31.5 dB Attenuator in 0.5 dB steps
> Cyclone II FPGA
> Two AD6620 DDC co-processors
> USB 2.0 480 Mbps High Speed Interface to PC
> 0.1 to 33 MHz coverage (0.1 to 65 MHz extended)
> RX bandwidths from 33 MHz to 1kHz
> Two independent RX channels anywhere in 0.1 to 33 MHz
> 6.00" X 4.00" board size
> Single +12V 1A supply
> Open Source Software and Hardware
>
> Prototype picture and preliminary info at:
>
> <http://pcovington.blogspot.com/>
>
> Soon to follow QS1R will be the QS1T transmitter board.
>
> 73 de Phil N8VB
Phil, this looks pretty good.

A quick comment, though.   Some of the daughtercards for the USRP 
produce complex baseband signals (I and Q), which
 are then sampled by the twin 12-bit A/Ds.   Since you are using 
real-mode only sampling, it would be inconvenient to
 attach (for example) a DBS_RX type front-end to your SDR card, since 
the DBS_RX uses a complex baseband.
 All of the modern satellite front-end chips, for example, use a 
complex-baseband direct-conversion approach.

My interest is radio astronomy, and while I'm perfectly happy with the 
USRP for my own use, I'd be happy to include support for
 your HPSDR card in my radio astronomy applications once your product 
is stable, and there's "driver" support in
 Gnu Radio for it...