[Premium-Rx] RFSpace SDR-14 digital receiver

[mikea]

Consider that the US military for some time has had people working on
"radios" which directly digitize the input RF and then Do Magic with
the digitized data. This is just the beginning of what we can expect
to see as the technology is developed for civilian use. I expect to
see SDRs in which the heavy lifting is done in the radio case, so that
a separate PeeCee isn't required. They probably won't be as big as my
Yaesu FRG-100, which is pretty small for 50 KHz to 30 MHz, and may
well wind up being about the same size as my Icom PCR-1000.

The price will drop pretty quickly, too, as the technology improves
and the demand increases. 

Gonna be a whole new world. 

On Fri, Jun 25, 2004 at 09:50:11AM -0500, Terry O'Laughlin wrote:
> My friend has a very well equipped test bench including esoteric stuff like 
> a noise figure meter.  He tested the SDR-14 and found it to be 
> excellent.  Sensitivity is superb, well under 1 uV across the range.  The 
> shape factors of the "IF filters" are beautiful.  The noise figure rose to 
> 11 dB in the 30 MHz range, but at HF frequencies that is decent and 
> comparable to most conventional receivers.  The box is very quiet emitting 
> almost no birdies.  We didn't discuss intermod or overload.  The box 
> digitizes right after a single preamp stage, so the ADC is the only 
> significant non-linear device in the RF chain.  I'd be curious to see IP3 
> and other performance test data.

> The DSP based demodulation is a CPU killer.  He runs a Pentium 2.8 GHz 
> machine and it is running flat out when demodulating.  A Pentium 1.7 GHz 
> machine runs the waterfall and SDU just fine but stumbled regularly on 
> demodulation finctions.  Hard drive space is also a factor as the SDR-14 in 
> record mode churns out data like a fire hydrant running wide open.

> It is so different from ordinary radios I found it hard to 
> compare.  Knowing that it is only the first device in a design trend and it 
> performs so well is amazing and begs the question, what is next?

> At 12:29 AM 6/25/2004, you wrote:
> >Keep in mind that the SDR-14 is more of a lab instrument, rather than
> >strictly a receiver. It will be lacking in certain performance specs that we
> >take for granted in a premium or "serious" consumer-grade receiver, for that
> >matter. From the rfspace.com web site:



-- 
Mike Andrews
mikea at mikea.ath.cx
Tired old sysadmin