[Elecraft] K3 & ADAT ADT-200A by HB9CBU

[Philip Covington]

On Tue, Dec 2, 2008 at 6:49 AM, Paul Christensen <w9ac at arrl.net> wrote:
>>> Its dynamic range may be OK for IMD but today's SDRs cannot approach the
>>> BDR of
>>> rigs like the K3 until even higher resolution ADCs become available.
>
>> Sorry to tell you a bad new: you are wrong!
> Nico & Phil,
>
> When can we expect to see direct R.F.-sampled SDRs with better MDS
> performance?   When we compare MDS data across QST product reviews in a 500
> Hz filter B/W, we see marginal figures of ~ -128 dBm @ 14 MHz.  This is true
> of the Perseus, SDR-IQ, and Flex 5000A.
>
> By contrast, radios such as the K3 and Orion offer excellent MDS figures
> approaching -140 dBm while still providing excellent close-spaced
> blocking and I3 dynamic range.
>
> Paul, W9AC
>

Hi Paul,

There is no inherent reason why the MDS could not be that low in
direct sampling SDRs.  It is mainly a matter of design
decision/implementation.

-- 
Phil Covington
Software Radio Laboratory LLC
Columbus, Ohio
http://www.srl-llc.com