[Elecraft] Son of K3??

[Geoffrey Mackenzie-Kennedy]

No criticism of Elecraft nor the K3 was intended, besides I do not have any 
good hard data as to the receive signal handling capability of the K3's DSP 
sub-system.

What triggered my comment was that the TS-590 is said to use only two 
roofing filters and it is claimed by the manufacturer that "it has the best 
receiver specs out there". If it is a superhet, this sounds suspiciously 
like a receiver that uses a H-Mode mixer, high IIP3 roofers, and a "strong" 
IF. The H-Mode is a type of mixer which appeared more than 15 years ago and 
yields very good  "IMD" performance, better than most, and as far as I know 
is not yet used in commercial amateur receivers - I don't know why not.

It will be interesting to see whether or not the designers of the TS-590 
receiver have used a proper Gain Distribution analysis to obtain optimum 
IMDDR3 performance, which should include every "stage" or element in or 
which impacts on the signal path, this includes L-C filters, crystal filters 
as well as LO phase noise. It will also be interesting to see their approach 
to the LO, because a PLL based synthesiser whose cost is within budget would 
probably be too "noisy".

All should be evident from the schematic when and if it becomes available.

73,

Geoff
GM4ESD


On Sunday, May 16, 2010, at 11:30 PM, Karl Marderian 
<karlmar at sbcglobal.net> wrote:

> For me and all others (I maybe the only one). Does this imply the
> enginreers at Elcraft need to do some brushing up on designing of DSPs.
> Are you saying their heterodynes aren't would they should be.
> N6XVT 73
>
> Sent from my iPhone