[Elecraft] K3 vs. HPSDR Mercury receiver

[Geoffrey Mackenzie-Kennedy]

David,

If you have not read it, the December 2008 issue of QST contains another 
review of the Perseus.

Although I own a Perseus, which I bought for use as a piece of test 
equipment, I do not own a K3 thus cannot compare their 'sound'. I can say 
though that I have never been comfortable with the 'sound' produced by most 
commercial amateur and military receivers which use DSP, but I do find that 
the 'sound' produced by Perseus, especially when a CW, SSB or AM signal is 
close to the ambient noise floor, is certainly not hard on the ears - it is 
quite mellow. Both its NB and NR work well.

73,
Geoff
GM4ESD



David Woolley (E.L) wrote:


> Dave G4AON wrote:
>> Members of the RSGB may wish to sneak a preview of the December
>> RadCom article on SDR where the authors compare a K3 with a HPSDR
>> Mercury receiver and explain why the SDR sounds better than the K3
>> (noise through a crystal filter causing phase changes).
>
> I've read the article and it is really comparing two types of SDR 
> receiver, rather than SDR and analogue.
>
> The type they are claiming the benefit for is one in which digitisation is 
> performed at signal frequency.  The other type is the design used by both 
> SoftRock and K3, in which the signal is first mixed down before being 
> digitised.
>
> The sort of noise they are talking about is impulsive noise, specifically 
> atmospherics due to global lightening.  A filter with non-constant group 
> delay will turn these from clicks to chirps.
>
> It is possible the SoftRock will do better in this respect, because 
> typical sound cards have a constant group delay anti-aliasing filter.
>>
>> http://www.rsgb.org/membersonly/radcom/techfeatures/sdr_1208.pdf
>>
>> </div>
>
>
> -- 
> David Woolley