Not today... but give it a couple years. There is a lot of R&D being poured into this by a number of competing chip manufacturers. Even if the next batch of designs falls a little short, an all digital design with BDR close to the best conventional designs would probably enjoy a very substantial market.
73, Larry N8LP Alan Bloom wrote: > On Mon, 2009-02-23 at 18:40, N8LP wrote: > ... > >> I think the days of receivers with xtal filters are numbered. High speed >> ADCs capable of 140dB dynamic range without xtal filtering are on the >> horizon. A 20-bit ADC with enough processing gain would do it. >> > > I don't think you'll find a 20-bit ADC with a high enough sample rate to > digitize the 3-30 MHz HF band (i.e. >65-70 MHz or so). At least not at > a reasonable cost. > > I believe the best suitable, reasonable-cost ADCs available these days > are able to achieve a 500-Hz blocking dynamic range in the low 120's dB, > maybe 15-20 dB worse than the K3. That's significantly better than the > previous generation of ADCs could achieve, and no doubt someday we'll > get even better parts that are good enough to challenge the traditional > superhet/crystal filter architecture. But I don't believe we're close > to that level of performance today. > > Another issue, of course, is spurious responses. I'm pretty sure that > current ADCs don't have good enough spurious-free dynamic range to > challenge a state-of-the-art receiver like the K3. > > Al N1AL > > > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
